Seagate, Seagate Technology, and the Seagate logo are registered trademarks of Seagate
Technology LLC. SeaTools, SeaFONE, SeaBOARD, and SeaTDD are either registered trade
marks or trademarks of Seagate Technology LLC. Other product names are registered trademarks or trademarks of their owners.
Seagate reserves the right to change , without notice, product offerings or specifications. No part
of this publication may be reproduced in any fo rm without written permission of Seagate Technol
This manual describes Seagate Technology® LLC, Cheetah® SAS (Serial Attached SCSI) disc drives.
Cheetah drives support the SAS Protocol specifications to the extent described in this manual. The SAS Inter-
face Manual (part number 100293071) describes the general SAS characteristics of Cheetah T10 and other
Seagate SAS drives.
Figure 1. Cheetah T10 SAS disc drive
Cheetah T10 SAS Product Manual, Rev. A1
2Cheetah T10 SAS Product Manual, Rev. A
2.0Sta ndards, compliance and reference documents
The drive has been developed as a system peripheral to the highest standards of design and construction. The
drive depends on its host equipment to provide adequate power and environment for optimum performance
and compliance with applicable industry and governmental regulations. Special attention must be given in th e
areas of safety, power distribution, shielding, audible noise control, and temperature regulation. In particular,
the drive must be securely mounted to guar antee the specified performance characteristics. Mounting by bot
tom holes must meet the requirements of Section 8.3.
2.1Standards
The Cheetah SAS family complies with Seagate standards as noted in the appropriate sections of this manual
and the Seagate SAS Interface Manual, part number 100293071.
The Cheetah disc drive is a UL recog nized com pon en t pe r UL1950 , CSA certified to CAN/CSA C22.2 No. 95095, and VDE certified to VDE 0805 and EN60950.
2.1.1Electromagnetic compatibility
The drive, as delivered, is designed for system integration and installation into a suitable enclosure prior to
use. The drive is supplied as a subasse mbly and is not s ubject to Subpart B o f Part 15 of the F CC Rules and
Regulations nor the Radio Interference Reg ula tio ns of the Canadian Department of Communications.
The design characteristics of the drive serve to minimize radiation when installed in an enclosure that provides
reasonable shielding. The drive is capable of meeting the Class B limits of the FCC Rules and Regulations of
the Canadian Department of Communications when properly packaged; however, it is the user ’s responsibility
to assure that the drive meets the appropriate EMI requirements in their system. Shielded I/O cables may be
required if the enclosure does not provide adequate shielding. If the I/O c ables are external to the enclosure,
shielded cables should be used, with the shields grounded to the enclosure and to the host controller.
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2.1.1.1Electromagnetic susceptibility
As a component assembly, the drive is not required to meet any susceptibility performance requirements. It is
the responsibility of those integrating the drive within their systems to perform those tests required and design
their system to ensure that equipment operating in the same system as the drive or external to the system
does not adversely affect the performance of the drive. See Tables
Cheetah T10 SAS Product Manual, Rev. A3
2, 3 and 4, for DC power requirements.
2.2Compliance
2.2.1Electromagnetic compliance
Seagate uses an independent laboratory to confirm compliance with the directives/standards for CE Marking
and C-Tick Marking. The drive was teste d in a repr esent ative system for typical applications. The selected sys
tem represents the most popular characteristics for test platforms. The system configurations include:
• Typical current use microprocessor
• 3.5-inch floppy disc drive
• Keyboard
• Monitor/display
• Printer
• External modem
•Mouse
Although the test system with this Seagate model complies with the directives/standards, we cannot guarantee
that all systems will comply. The computer manufacturer or system integrator shall confirm EMC compliance
and provide the appropriate marking for their product.
Electromagnetic compliance for the European Union
If this model has the CE Marking it complies with the European Union requirements of the Electromagnetic
Compatibility Directive 89/336/EEC of 03 May 1989 as amended by Directive 92/31/EEC of 28 April 1992 and
Directive 93/68/EEC of 22 July 1993.
-
Australian C-Tick
If this model has the C-Tick Marking it complies with the Australia/New Zealand Standard AS/NZS3548 1995
and meets the Electromagnetic Compatibility (EMC) Framework requirements of Australia’s Spectrum Man
agement Agency (SMA).
Korean MIC
If this model has the Korean Ministry of Information and Communication (MIC) logo, it complies with paragraph
1 of Article 11 of the Electromagnetic Compatibility (EMC) Control Regulation and meets the Electromagnetic
Compatibility Framework requirements of the Radio Research Laboratory (RRL) Ministry of Information and
Communication Republic of Korea.
Taiwanese BSMI
If this model has two Chinese words meaning “EMC certification” followed by an eight digit identification num-
ber, as a Marking, it complies with Chinese National Standard (CNS) 13438 and meets the Electromagnetic
Compatibility (EMC) Framework requirements of the Taiwanese Bureau of Standards, Metrology, and Inspec
tion (BSMI).
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4Cheetah T10 SAS Product Manual, Rev. A
2.3Reference documents
Cheetah T10 SAS Installation GuideSeagate part number: 100433695
SCSI Commands Reference ManualSeagate part number: 100293068
SAS Interface ManualSeagate part number: 100293071
Applicable ANSI SAS documents
SFF-83233.5” Drive Form Factor with Serial Connector
SFF-8460HSS Backplane Design Guidelines
SFF-8470Multi Lane Copper Connector
SFF-8482SAS Plug Connector
ANSI INCITS.xxx Serial Attached SCSI (SAS) Standard (T10/1562-D)
ISO/IEC 14776-xxx SCSI Architecure Model-3 (SAM-3) Standard (T10/1561-D)
ISO/IEC 14776-xxx SCSI Primary Commands-3 (SPC-3) Standard (T10/1416-D)
ISO/IEC 14776-xxx SCSI Block Commands-2 (SBC-2) St andard (T10/1417-D)
ANSI Small Computer System Interface (SCSI) Documents X3.270-1996(SCSI-3) Architecture Model
Specification for Acoustic Test Requirement and ProceduresSeagate part number: 30553-001
Package Test SpecificationSeagate P/N 30190-001 (under 100 lb.)
Package Test SpecificationSeagate P/N 30191-001 (over 100 lb.)
In case of conflict between this document and any referenced document, this document takes precedence.
Cheetah T10 SAS Product Manual, Rev. A5
6Cheetah T10 SAS Product Manual, Rev. A
3.0General description
Cheetah drives combine giant magnetoresistive (GMR) heads, partial response/maximum likelihood (PRML)
read channel electronics, embedded servo technology, and a Serial Attached SCSI (SAS) interface to provide
high performance, high capacity data storage for a variety of systems including engineering workstations, net
work servers, mainframes, and superc om p uter s. T he Serial Attached SCSI interface is designed to meet nextgeneration computing demands for performance, scalability, flexibility and high-density storage requirements.
Cheetah drives are random access storage devices designed to support the Serial Attached SCSI Protocol as
described in the ANSI specifications, this document, and the SAS Interface Manual (part number 100293071)
which describes the general interface characteristics of this drive. Cheetah drives are classified as intelligent
peripherals and provide level 2 conformance (highest level) with the ANSI SCSI-1 standard. The SAS connec
tors, cables and electrical interface are compatible with Serial ATA (SATA), giving future users the choice of
populating their systems with either SAS or SATA hard disc drives. This allows you to continue to leverage your
existing investment in SCSI while gaining a 3Gb/s serial data transfer rate.
The head and disc assembly (HDA) is sealed at the factory. Air recirculates within the HDA through a nonreplaceable filter to maintain a contamination-free HDA environment.
Note.Never disassemble the HDA and do not attempt to service items in the sealed enclosure (heads,
media, actuator, etc.) as this requires special facilities. The drive does not contain user-replaceable
parts. Opening the HDA for any reason voids your warranty.
Cheetah drives use a dedicated landing zone at the innermost radius of the media to eliminate the possibility of
destroying or degrading data by landin g in the dat a zone. The heads automatically go to the landing zone when
power is removed from the drive.
-
-
An automatic shipping lock prevents potential damage to the heads and discs that results from movement during shipping and handling. The shipping lock disengages and the head load process begins when power is
applied to the drive.
Cheetah drives decode track 0 location data from the servo data embedded on each surface to eliminate
mechanical transducer adjustments and related reliability concerns.
The drives also use a high-performance actuator assembly with a low-inertia, balanced, patented, straight arm
design that provides excellent performance with minimal power dissipation.
Cheetah T10 SAS Product Manual, Rev. A7
3.1Standard features
Cheetah drives have the following standard features:
• 1.5 / 3Gbit Serial Attached SCSI (SAS ) interface
• Integrated dual port SAS controller supporting the SCSI protocol
• Support for SAS expanders and fanout adapters
• Firmware downloadable using the SAS interface
• 128-deep task set (queue)
• Supports up to 32 initiators
• Jumperless configuration.
• User-selectable logical block size (512, 520, 524, or 528 bytes per logical block)
• Perpendicular recording technology
• Programmable logical block reallocation scheme
• Flawed logical block reallocation at format time
• Programmable auto write and read reallocation
• Reallocation of defects on command (Post Format)
• ECC maximum burst correction length of 320 bits
• No preventive maintenance or adjustments required
• Dedicated head landing zone
• Embedded servo design
• Automatic shipping lock
• Embedded servo design
• Self diagnostics performed when power is applied to the drive
• Zone bit recording (ZBR)
• Vertical, horizontal, or top down mounting
• Dynamic spindle brake
• 16 Mbyte data buffer (see Section 4.5).
• Drive Self Test (DST)
• Background Media Scan (BGMS)
•Power Save
3.2Media description
The media used on the drive has an aluminum substrate coated with a thin film magnetic material, ov e rcoa t ed
with a proprietary protective layer for improved durability and environmental protection.
3.3Performance
• Programmable multi-segmentable cache buffer
• 300 Mbytes/sec maximum instantaneous data transfers.
• 15k RPM spindle. Average latency = 2.0 msec
• Background processing of queue
• Supports start and stop commands (spindle stops spinning)
• 1,400,000 hour MTBF (Annualized Failure Rate (AFR) of 0.62%)
• Incorporates industry-standard Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.)
• 5-year warranty
3.5Formatted capacities
Standard OEM models are formatted to 512 bytes per block. The block size is selectable at format time and
must be a multiple of 4 bytes. Users having the necessary equipment may modify the data block size before
issuing a format command and obtain different formatted capacities than those listed.
To provide a stable target capacity environment and at the same time provide users with flexibility if they
choose, Seagate recommends product planning in one of two modes:
1. Seagate designs specify capacity points at ce rtain block sizes that Seagate guarantees current and future
products will meet. We recommend customers use this capacity in their project planning, as it ensures a
stable operating point with backward and forward compatibility from generation to generation. The current
guaranteed operating points for this product are:
2. Seagate drives also may be use d at the maximu m ava ilable capacity at a give n blo ck size , but the exce ss
capacity above the guaranteed level will vary between other drive families and from generation to genera
tion, depending on how each block size actually formats out for zone frequencies and splits over servo
bursts. This added capacity potential may range from 0.1 to 1.3 percent above the guaranteed capacities
listed above. Using the drives in this manner gives the absolute maximum capacity potential, but the user
must determine if the extra capacity potential is useful, or whether their assurance of backward and for
ward compatibility takes precedence.
3.6Programmable drive capacity
Using the Mode Select command, the drive can change its capacity to something less than maximum. See the
Mode Select (6) parameter list table in the SAS Interface Manual, part number 100293071. A value of zero in
the Number of Blocks field indicates that the drive will not change the capacity it is currently formatted to have.
A number other than zero and less than the maximum number of LBAs in the Number of Blocks field changes
the total drive capacity to the value in the Number of Blocks field. A value greater than the maximum numbe r of
LBAs is rounded down to the maximum capacity.
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3.7Factory-installed accessories
OEM standard drives are shipped with the Cheetah T10 SAS Installation Guide, part number 100433695, and
the Safety and Regulatory Agency Specifications, part number 75789512 (unless otherwise specified).
Cheetah T10 SAS Product Manual, Rev. A9
3.8Options (factory installed)
You may order the following items which are incorporated at the manufacturing facility during production or
packaged before shipping. Some of the options available are (not an exhaustive list of possible options):
• Other capacities can be ordered depending on sparing scheme and sector size requested.
• Single-unit shipping pack. The drive is normally shipped in bulk packaging to provide maximum protec tion
against transit damage. Units shipped individually require additional protection as p rovided by the sin gle unit
shipping pack. Users planning single unit distribution should specify this option.
•The Cheetah T10 SAS Installation Guide, part number 100433695, is usually included with each standard
OEM drive shipped, but extra copies may be ordered.
•The Safety and Regulatory Agency Specifications, part number 75789512, is usually included with each
standard OEM drive shipped, but extra copies may be ordered.
3.9User-installed accessories
The following accessory is available:
• Single-unit shipping pack.
10Cheetah T10 SAS Product Manual, Rev. A
4.0Performance characteristics
This section provides detailed information concerning performance-related characteristics and features of
Cheetah drives.
4.1Internal drive characteristics
ST3300555SS ST3146755SS ST373355SS
Drive capacity300.0146.873.4Gbytes (formatted, rounded off value)
Read/write data heads842
Tracks per surface (total)74,34074,34074,340Tracks (user accessible)
Tracks per inch125,000125,000125,000TPI
Peak bits per inch890k890k890kKBPI
Areal Density110110110Gbits/inch
Internal data rate960 to 1607960 to 1607960 to 1607Mbits/sec (variable with zone)
Disc rotation speed15k15k15krpm
Avg rotational latency2.02.02.0msec
*One Gbyte equals one billion bytes when referring to hard drive capacity. Accessible capacity may vary depending on operating environment
and formatting.
**Rounded off value.
2
*,**
4.2Seek time
See Section 9.4.1, "SAS physical interface" on page 57 and the SAS Interface Manual (part number
100293071) for additional timing details.
4.2.1Access time
Not Including controller overhead
ReadWrite
AverageTypical3.54.0
Single trackTypical0.20.4
Full strokeTypical6.87.5
1, 2
(msec)
1.Typical access times are measured under nominal conditions of temperature, voltage,
and horizontal orientation as me asured on a representative sample of drives.
2.Access to data = access time + latency time.
Cheetah T10 SAS Product Manual, Rev. A11
4.2.2Format command execution time (minutes)
ST3300555SSST3146755SSST373355SS
Maximum (with verify)
Maximum (without verify)
1459060
904530
Execution time measured from receipt of the last byte of the Command Descriptor Block (CDB) to the request
for a Status Byte Transfer to the Initiator (excluding connect/disconnect).
4.2.3General performance characteristics
Sustainable disc transfer rate*:
Minimum55.5 Mbytes/sec
Maximum93 Mbytes/sec
SAS Interface maximum instantaneous transfer rate300 Mbytes/sec* per port
Logical block sizes
Default is 512-byte data blocks
Sector sizes variable to 512, 520, 524 an 528 bytes.
Read/write consecutive sectors on a trackYes
Flaw reallocation performance impact (for flaws reallocated at format time using
the spare sectors per sparing zone reallocation scheme.)
Average rotational latency2.0 msec
*Assumes system ability to support the rates listed and no cable loss.
(dual port = 600 Mbytes/sec*)
Negligible
4.3Start/stop time
The drive accepts the commands listed in the SAS Interface Manual less than 3 seconds after DC power has
been applied.
If the drive receives a NOTIFY (ENABLE SPINUP) primitive through either port and has not received a START
STOP UNIT command with the START bit equal to 0, the drive becomes ready for normal operations within 20
seconds (excluding the error recovery procedure).
If the drive receives a START STOP UNIT command with the START bit equal to 0 before receiving a NOTIFY
(ENABLE SPINUP) primitive, the drive waits for a START ST OP UNIT command with the START bit equal to 1.
After receiving a START STOP UNIT command with the START bit equal to 1, the drive waits for a NOTIFY
(ENABLE SPINUP) primitive. After receiving a NOTIFY (ENABLE SPINUP) primitive through either port, the
drive becomes ready for normal operations within 20 seconds (excluding the error recovery procedure).
If the drive receives a START STOP UNIT command with the START bit and IMMED bit equal to 1 and does
not receive a NOTIFY (ENABLE SPINUP) primitive within 5 seconds, the drive fails the START STOP UNIT
command.
12Cheetah T10 SAS Product Manual, Rev. A
The ST AR T STOP UNIT command may be used to command the drive to stop the spindle. Stop time is 30 seconds (maximum) from removal of DC power. There is no power control switch on the drive.
4.4Prefetch/multi-segmented cache control
The drive provides a prefetch (read look-ahead) and multi-segmented cache control algorithms that in many
cases can enhance system performance. Cache refers to the drive buffer storage space when it is used in
cache operations. To select this feature, the host sends the Mode Select command with the proper va lues in
the applicable bytes in page 08h. Prefetch and cache operations are independent features from the standpoint
that each is enabled and disabled independently using the Mode Select command; however, in actual opera
tion, the prefetch feature overlaps cache operation somewhat as described in sections 4.5.1 and 4.5.2.
All default cache and prefetch mode parameter values (Mode Page 08h) for standard OEM versions of this
drive family are given in Section
9.3.2.
4.5Cache operation
Note.Refer to the SAS Interface Manual for more detail concerning the cache bits.
Of the 16 Mbytes physical buffer space in the drive, approximately 13,000 kbytes can be used as a cache. The
buffer is divided into logical segments from which data is read and to which data is written.
The drive keeps track of the logical block addresses of the data stored in each segment of the buffer. If the
cache is enabled (see RCD bit in the SAS Interface Manual
is retrieved from the buffer, if possible, before any disc access is initiated. If cache operation is not enabled, the
buffer is still used, but only as circular buffer segments during disc medium read operations (disregarding
Prefetch operation for the moment). That is, the drive does not check in the buffer segments for the requested
read data, but goes directly to the medium to retrieve it. The retrieved data merely passes through some buffer
segment on the way to the host. All data transfers to the host are in accordance with buffer-full ratio rules. See
the explanation provided with the information about Mode Page 02h (disconnect/reconnect control) in the SAS
Interface Manual.
), data requested by the host with a read comman d
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The following is a simplified description of the prefetch/cache operation:
Case A—read command is received and all of the requested logical blocks are already in the cache:
1. Drive transfers the requested logical blocks to the initiator.
Case B—A Read command requests data, and at least one requested logical block is not in any segment of
the cache:
1. The drive fetches the requested logical blocks from the disc and transfers them into a segment, and then
from there to the host in accordance with the Mode Select Disconnect/Reconnect parameters, page 02h.
2. If the prefetch feature is enabled, refe r to sec tio n 4.5.2 for operation from this point.
Each cache segment is actually a self-contained circular buffer whose length is an integer number of logical
blocks. The drive dynamically creates and removes segments based on the workload. The wrap-around capa
bility of the individual segments greatly enhances the cache’s overall performance.
Note.The size of each segment is not reported by Mode Sense command page 08h, bytes 14 and 15.
The value 0XFFFF is always reported regardless of the actual size of the segment. Sending a size
specification using the Mode Select command (bytes 14 and 15) does not set up a new segment
size. If the STRICT bit in Mode page 00h (byte 2, bit 1) is set to one, the drive responds as it does
for any attempt to change an unchangeable parameter.
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Cheetah T10 SAS Product Manual, Rev. A13
4.5.1Caching write data
Write caching is a write operation by the drive that ma kes use o f a drive b uffer storage area wher e the da ta to
be written to the medium is stored while the drive performs the Write command.
If read caching is enabled (RCD=0), then data written to the medium is retained in the cache to be made available for future read cache hits. The same buffer space and segmentation is used as set up for read functions.
The buffer segmentation scheme is set up or changed independently, having nothing to do with the state of
RCD. When a write command is issued, if RCD=0, the cache is first checked to see if any logical blocks that
are to be written are already stored in the cache from a previous read or write command. If there are, the
respective cache segments are cleared. The new data is cached for subsequent Read commands.
If the number of write data logical blocks exceed the size of the se gment being written into, when the end of the
segment is reached, the data is written into the beginning of the same cache segment, overwriting the data that
was written there at the beginning of the operation; however, the drive does not overwrite data that has not yet
been written to the medium.
If write caching is enabled (WCE=1), then the drive may return Good status on a write command after the data
has been transferred into the cache, but before the data has been written to the medium. If an error occurs
while writing the data to the medium, and Good status has already been returned, a deferred error will be gen
erated.
The Synchronize Cache command may be used to force the drive to write all cached write data to the medium.
Upon completion of a Synchronize Cache command, all data received from previous write commands will have
been written to the medium.
Tables 10, 11, and 12 shows the mode default settings for the drives.
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4.5.2Prefetch operation
If the Prefetch feature is enabled, data in contiguous logical blocks on the disc immediately beyond that which
was requested by a Read command are retrieved and stored in the buffer for immediate transfer from the
buffer to the host on subsequent Read commands that request those logical blocks (this is true even if cache
operation is disabled). Though the pr ef etch operation uses the buffer as a cache, finding the requested data in
the buffer is a prefetch hit, not a cache operation hit.
To enable Prefetch, use Mode Select page 08h, byte 12, bit 5 (Disable Read Ahead - DRA bit). DRA bit = 0
enables prefetch.
The drive does not use the Max Prefetch field (bytes 8 and 9) or the Prefetch Ceiling field (bytes 10 and 11).
When prefetch (read look-ahead) is enabled (enabled by DRA = 0), the drive enables prefetch of contiguous
blocks from the disc when it senses that a prefetch hit will likely occur. The drive disables prefetch when it
decides that a prefetch hit is not likely to occur.
14Cheetah T10 SAS Product Manual, Rev. A
5.0Reliability specifications
The following reliability specifications assume correct host and drive operational interface, including all interface timings, power supply voltages, environmental requirements and drive mounting constraints.
Seek error rate:Less than 10 errors in 108 seeks
Read Error Rates
Recovered DataLess than 10 errors in 1012 bits transferred (OEM default settings)
Unrecovered DataLess than 1 sector in 1016 bits transferred
Miscorrected DataLess than 1 sector in 1021 bits transferred
Interface error rate:Less than 1 error in 1012 bits transferred
MTBF1,400,000 hours
Preventive maintenance:None required
1.Error rate specified with automatic retries and data correction with ECC enabled and all flaws reallocated.
1
5.1Error rates
The error rates stated in this manual assume the following:
• The drive is operated per this specification using DC power as defined in this manual (see Section 6.2).
• Errors caused by host system failures are excluded from error rate computations.
• Assume random data.
• Default OEM error recovery settings are applied. This includes AWRE, ARRE, full read retries, full write
retries and full retry time.
5.1.1Recoverable Errors
Recovereable errors are those detected and corrected by the drive, and do not require user intervention.
Recoverable Data errors will use correction, although ECC on-the-fly is not considered for purposes of recov-
ered error specifications.
Recovered Data error rate is determined using read bits transferred for recoverab le errors occurring during a
read, and using write bits transferred for recoverable errors occurring during a write.
5.1.2Unrecoverable Errors
Unrecoverable Data Errors (Sense Key = 03h) are specified at less than 1 sector in error per 1016 bits transferred. Unrecoverable Data Errors resulting from the same cause are treated as 1 error for that block.
Cheetah T10 SAS Product Manual, Rev. A15
5.1.3Seek errors
A seek error is defined as a failure of the drive to position the heads to the addressed track. After detecting an
initial seek error, the drive automatically performs an error recovery process. If the error recovery process fails,
a seek positioning error (Error code = 15h or 02h) will be reported with a Hardware error (04h) in the Sense
Key. Recoverable seek errors are specified at Less than 10 errors in 10
8
seeks. Unrecoverable seek errors
(Sense Key = 04h) are classified as drive failures.
5.1.4Interface errors
An interface error is defined as a failure of the receiver on a port to recover the data as transmitted by the
device port connected to the receiver. The error may be detected as a running disparity error, illegal code, loss
of word sync, or CRC error.
5.2Reliability and service
You can enhance the reliability of Cheetah disc drives by ensuring that the drive receives adequate cooling.
Section 6.0 provides temperature measurements and other information that may be used to enhance the service life of the drive. Section 8.2 provides recommended air-flow information.
5.2.1Mean time between failure (MTBF)
The production disc drive shall achieve a MTBF of 1,400,000 hours when operated in an environment that
ensures the HDA case temperatures specified in Section
the specification limits of the operating environment will not affect MTBF performance. Continual or sustained
operation at case temperatures above the values shown in Section
6.4 are not exceeded. Short-term excursions up to
6.4.1 may degrade product reliability.
The MTBF target is specified as device power-on hours (POH) for all drives in service per failure.
MTBF =Estimate power-on operating hours in the period
----------------------------------------------------------------Number of drive failures in the period
Estimated power-on operation hours means power-up hours per disc drive times the total number of disc
drives in service. Each disc drive shall have accumulated at least nine months of operation. Data shall be cal
culated on a rolling average base for a minimum period of six months.
MTBF is based on the following assumptions:
• 8,760 power-on hours per year.
• 250 average on/off cycles per year.
• Operations at nominal voltages.
• Systems will provide adequate cooling to ensure the case temperatures specified in Sectio n 6.4.1 are not
exceeded.
Drive failure means any stoppage or substandard performance caused by drive malfunction.
A S.M.A.R.T. predictive failure indicates that the drive is deteriorating to an imminent failure and is considered
an MTBF hit.
5.2.2Preventive maintenance
No routine scheduled preventive maintenance is required.
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16Cheetah T10 SAS Product Manual, Rev. A
5.2.3Hot plugging the drive
When a disc is powered on by switching the power or hot plugged, the drive runs a self test before attempting
to communicate on its’ interfaces. When the self test completes successfully, the drive initiates a Link Reset
starting with OOB. An attached device should respond to the link reset. If the link reset attempt fails, or any
time the drive looses sync, the drive initiated link reset. The drive will initiate link reset once per second but
alternates between port A and B. Therefore each port will attempt a link reset once per 2 seconds assuming
both ports are out of sync..
If the self-test fails, the does not respond to link reset on the failing port.
Note.It is the responsibility of the systems integrator to assure that no temperature, energy, voltage haz-
ard, or ESD potential hazard is presented during the hot connect/disconnect operation. Discharge
the static electricity from the drive carrier prior to inserting it into the system.
Caution. The drive motor must come to a complete stop prior to changing the plane of operation. This time is
required to insure data integrity.
5.2.4S.M.A.R.T.
S.M.A.R.T. is an acronym for Self-Monitoring Analysis and Reporting Technology. This technology is intended
to recognize conditions that indicate imminent drive failure and is designed to provide sufficient warning of a
failure to allow you to back up the data before an actual failure occurs.
Note.The drive’s firmware monitors specific attributes fo r degradation over time but can’t predict insta nta-
neous drive failures.
Each monitored attribute has been selected to monitor a specific set of failure conditions in the operating performance of the drive and the thresholds are optimized to minimize “false” and “failed” predictions.
Controlling S.M.A.R.T.
The operating mode of S.M.A.R.T. is controlled by the DEXCPT and PERF bits on the Informa tional Exceptions
Control mode page (1Ch). Use the DEXCPT bit to en able or disable the S.M.A.R.T. feature. Setting the DEX
CPT bit disables all S.M.A.R.T. functions. When enabled, S.M.A.R.T. collects on-line data as the drive performs
normal read and write operations. When the PERF bit is set, the drive is considered to be in “On-line Mode
Only” and will not perform off-line functions.
You can measure off-line attributes and force the drive to save the data by using the Rezero Unit command.
Forcing S.M.A.R.T. resets the timer so that the next scheduled interrupt is in two hours.
You can interrogate the drive through the host to determine the time remaining before the next scheduled mea surement and data logging process occurs. To accomplish this, issue a Log Sense command to log page 0x3E.
This allows you to control when S.M.A.R.T. interruptions occur. Forcing S.M.A.R.T. with the RTZ command
resets the timer.
Performance impact
S.M.A.R.T. attribute data is saved to the disc so that the events that caused a predictive failure can be recreated. The drive measures and saves paramete rs once every two hours subject to an idle period on the drive
interfaces. The process of measuring off-line attribute data and saving data to the disc is uninterruptable. The
maximum on-line only processing delay is summarized below:
Maximum processing delay
-
S.M.A.R.T. delay times
On-line only delay
DEXCPT = 0, PERF = 1
42 milliseconds
Fully-enabled delay
DEXCPT = 0, PERF = 0
163 milliseconds
Cheetah T10 SAS Product Manual, Rev. A17
Reporting control
Reporting is controlled by the MRIE bits in the Informational Exceptions Control mode page (1Ch). Subject to
the reporting method, the firmware will issue to the host an 01-5Dxx sense code. The error code is preserved
through bus resets and power cycles.
Determining rate
S.M.A.R.T. monitors the rate at which errors occur and signals a predictive failure if the ra te of d eg raded erro rs
increases to an unacceptable level. To determine rate, error events are logged and compare d to the num ber of
total operations for a given attribute. The interval defines the nu mber of oper ations o ver whic h to me asure the
rate. The counter that keeps track of the current number of operations is referred to as the Interval Counter.
S.M.A.R.T. measures error rates. All errors for each monitored attribute are recorded. A counter ke eps track of
the number of errors for the current interval. This counter is referred to as the Failure Counter.
Error rate is the number of errors per operation. The algori thm that S.M.A.R.T. uses to record rates of error is to
set thresholds for the number of errors and their interval. If the number of errors exceeds the threshold before
the interval expires, the error rate is considered to be unacceptable. If the number of errors does not exceed
the threshold before the interval expires, the error rate is considered to be acceptable. In either case, the inter
val and failure counters are reset and the process starts over.
Predictive failures
S.M.A.R.T. signals predictive failures when the drive is performing unacceptably for a period of time. The firmware keeps a running count of the number of times the error rate for each attribute is unacceptable. To accomplish this, a counter is incremented e ach time the erro r rate is unacceptable and decremented (not to exceed
zero) whenever the error rate is acceptable. If the counter continually increments such that it reaches the pre
dictive threshold, a predictive failure is signaled. This counter is referred to as the Failure History Counter.
There is a separate Failure History Counter for each attribute.
-
-
5.2.5Thermal monitor
Cheetah drives implement a temperature warning system which:
1. Signals the host if the temperature exceeds a value which would threaten the drive.
2. Signals the host if the temperature exceeds a user-specified value.
3. Saves a S.M.A.R.T. data frame on the drive which exceeds the threatening temperature value .
A temperature sensor monitors the drive temperature and issues a warning over the interface when the temperature exceeds a set th reshold. The t emperature is measured a t power-up an d then at te n-minute interv als
after power-up.
The thermal monitor system generates a warning code of 01-0B01 when the temperature exceeds the specified limit in compliance with the SCSI standard. The drive temperature is reported in the FRU code field of
mode sense data. You can use this information to determine if the warning is due to the temperature exceeding
the drive threatening temperature or the user-specified temperature.
This feature is controlled by the Enable Warning (EWasc) bit, and the reporting mechanism is controlled by the
Method of Reporting Informational Exceptions field (MRIE) on the Informational Exceptions Control (IEC)
mode page (1Ch).
The current algorithm implem ents two temperature trip points. The first trip point is set at 68°C which is the
maximum temperature limit according to the drive specification. The second trip point is user-selectable using
the Log Select command. The reference temperature parameter in the temperature log page (see Table
1) can
18Cheetah T10 SAS Product Manual, Rev. A
be used to set this trip point. The default value for this drive is 68°C, however, you can set it to any value in the
range of 0 to 68°C. If you specify a temperature greater than 68°C in this field, the temperature is rounded
down to 68°C. A sense code is sent to the host to indicate the rounding of the parameter field.
Table 1: Temperature Log Page (0Dh)
Parameter CodeDescription
0000h
0001h
Primary Temperature
Reference Temperature
5.2.6Drive Self Test (DST)
Drive Self Test (DST) is a technology designed to recognize drive fault conditions that qualify the drive as a
failed unit. DST validates the functionality of the drive at a system level.
There are two test coverage options implemented in DST:
1. Extended test
2. Short text
The most thorough option is the extended test that performs var io us t es ts on the driv e a nd sca n s ev er y lo gical
block address (LBA) of the drive. The short test is time-restricted and limited in length—it does not scan the
entire media surface, but does some fundamental tests and scans portions of the media.
If DST encounters an error during either of these tests, it reports a fault condition. If the drive fails the test,
remove it from service and return it to Seagate for service.
5.2.6.1DST failure definition
The drive will present a “diagnostic failed” condition through the self-tests results value of the diagnostic log
page if a functional failure is encountered during DST. The channel and servo parameters are not modified to
test the drive more stringently, and the number of retries are not reduced. All retries and recovery processes
are enabled during the test. If data is recoverable, no failure condition will be reported regardless of the number
of retries required to recover the data.
The following conditions are considered DST failure conditions:
• Seek error after retries are exhausted
• Track-follow error after retries are exhausted
• Read error after retries are exhausted
• Write error after retries are exhausted
Recovered errors will not be reported as diagnostic failures.
5.2.6.2Implementation
This section provides all of the information necessary to implement the DST function on this drive.
Cheetah T10 SAS Product Manual, Rev. A19
5.2.6.2.1State of the drive prior to testing
The drive must be in a ready state before issuing the Send Diagnostic command. There are multiple reasons
why a drive may not be ready, some of which are valid conditions, and not errors. For example, a drive may be
in process of doing a format, or another DST. It is the responsibility of the host application to determine the “not
ready” cause.
While not technically part of DST, a Not Ready condition also qualifies the drive to be returned to Seagate as a
failed drive.
A Drive Not Ready condition is reported by the drive under the following conditions:
• Motor will not spin
• Motor will not lock to speed
• Servo will not lock on track
• Drive cannot read configuration tables from the disc
In these conditions, the drive responds to a Test Unit Ready command with an 02/04/00 or 02/04/03 code.
5.2.6.2.2Invoking DST
To invoke DST, submit the Send Diagnostic command with the appropriate Function Code (001b for the short
test or 010b for the extended test) in bytes 1, bits 5, 6, and 7.
5.2.6.2.3Short and extended tests
DST has two testing options:
1. short
2. extended
These testing options are described in the following two subsections.
Each test consists of three segments: an electrical test segment, a servo test segment, and a read/ve rify s can
segment.
Short test (Function Code: 001b)
The purpose of the short test is to provide a time-limited test that tests as much of the drive as possible within
120 seconds. The short test does not scan the entire media surface, but does some fundamental tests and
scans portions of the media. A complete read/verify scan is not performed and only factual failures will report a
fault condition. This option provides a quick confidence test of the drive.
Extended test (Function Code: 010b)
The objective of the extended test option is to empirically test critical drive componen ts. For example, the seek
tests and on-track operations test the positioning mechanism. The read operation tests the read head element
and the media surface. The write element is tested through read/write/read operations. The integrity of the
media is checked through a read/verify scan of the media. Motor functionality is tested by default as a part of
these tests.
The anticipated length of the Extended test is reported through the Control Mode page.
5.2.6.2.4Log page entries
When the drive begins DST, it creates a new entry in the Self-test Results Log page. The new entry is created
by inserting a new self-test parameter block at the b eginning of the self- test result s log parame ter section of the
log page. Existing data will be moved to make room for the new parameter block. The drive reports 20 param
eter blocks in the log page. If there are more than 20 parameter blocks, the least recent parameter block will be
deleted. The new parameter block will be initialized as follows:
1. The Function Code field is set to the same value as sent in the DST command
-
20Cheetah T10 SAS Product Manual, Rev. A
2. The Self-Test Results Va lue field is set to Fh
3. The drive will store the log page to non-volatile memory
After a self-test is complete or has been aborted, the drive updates the Self-Test Results Value field in its Self-
Test Results Log page in non-volatile memory. The host may use Log Sense to read the results from up to the
last 20 self-tests performed by the drive. Th e se lf- te st r esults value is a 4-bit field that reports the results of the
test. If the field is set to zero, the drive passed with no errors detected by the DST. If the field is not set to zero,
the test failed for the reason reported in the field.
The drive will report the failure condition and LBA (if applicable) in the Self-test Results Log parameter. The
Sense key, ASC, ASCQ, and FRU are used to report the failure condition.
5.2.6.2.5Abort
There are several ways to abort a diagnostic. You can use a SCSI Bus Reset or a Bus Device Reset message
to abort the diagnostic.
You can abort a DST executing in background mode by using the abort code in the DST Function Code field.
This will cause a 01 (self-test aborted by the application client) code to appear in the self-test results values
log. All other abort mechanisms will be reported as a 02 (self-test routine was interrupted by a reset condition).
5.2.7Product warranty
Beginning on the date of shipment to the customer and continuing for the period specified in your purchase
contract, Seagate warrants that each product (including components and subassemblies) that fails to function
properly under normal use due to defect in materia ls or workmanshi p or due to noncon formance to the applica
ble specifications will be repaired or replaced, at Seagate’s option and at no charge to the customer , if returned
by customer at customer’s expense to Seagate’s designated facility in accordance with Seagate’s warranty
procedure. Seagate will pay for transporting the repair or replacement item to the customer. For more detailed
warranty information, refer to the standard terms and conditions of purchase for Seagate products on your pur
chase documentation.
-
-
The remaining warranty for a particular drive can be determined by calling Seagate Customer Service at
1-800-468-3472. You can also determine remaining warranty using the Seagate web site (www.seagate.com).
The drive serial number is required to determine remaining warranty information.
Shipping
When transporting or shipping a drive, use only a Seagate-approved container. Keep your original box.
Seagate approved containers are easily identified by the Se agat e Ap pr oved Package la be l. Shipp ing a drive in
a non-approved container voids the drive warranty.
Seagate repair centers may refuse receipt of components improperly packaged or obviously damaged in transit. Contact your authorized Seagate distributor to purchase additi onal boxes. S eagate recommends shipping
by an air-ride carrier experienced in handling computer equipment.
Product repair and return information
Seagate customer service centers are the only facilities authorized to service Seagate drives. Seagate does
not sanction any third-party repair facilities. Any unauthorized repair or tampering with the factory seal voids
the warranty.
Cheetah T10 SAS Product Manual, Rev. A21
22Cheetah T10 SAS Product Manual, Rev. A
6.0Physical/electrical specifications
This section provides information relating to the physical and electrical characteristics of the drive.
6.1AC power requirements
None.
6.2DC power requirements
The voltage and current requirements for a single drive are shown below. Values indicated apply at the drive
connector.
Table 2: ST3300555SS DC power requirements
ST3300555SS
1.5 Gbit mode
Notes
Voltage+5V+12V [2]+5V+12V [2]
Regulation[5]±5%±5% [2]±5%±5% [2]
Avg idle current DCX[1] [6]0.790.850.780.86
Maximum starting current
(peak DC) DC3σ[3]0.901.980.891.97
(peak AC) AC3σ[3]1.193.321.213.28
Delayed motor start (max) DC 3σ[1] [4]0.650.030.680.03
Peak operating current:
Typical DCX[1]0.781.020.811.03
Maximum DC3σ[1]0.801.040.831.05
Maximum (peak) DC3σ1.582.861.582.82
0.15A DC and 0.2A AC 12V max start current margin added.
(Amps)(Amps)(Amps)(Amps)
ST3300555SS
3 Gbit mode
Cheetah T10 SAS Product Manual, Rev. A23
Table 3: ST3146755SS DC power requirements
ST3146755SS
1.5 Gbit mode
Notes
Voltage+5V+12V [2]+5V+12V [2]
Regulation[5]±5%±5% [2]±5%±5% [2]
Avg idle current DCX[1] [6]0.800.570.780.57
Maximum starting current
(peak DC) DC3σ[3]0.872.120.871.93
(peak AC) AC3σ[3]1.203.491.213.45
Delayed motor start (max) DC 3σ[1] [4]0.640.030.680.03
Peak operating current:
Typical DCX[1] 0.780.760.810.76
Maximum DC3σ[1]0.780.780.820.78
Maximum (peak) DC3σ1.602.541.622.62
0.15A DC and 0.2A AC 12V max start current margin added..
(Amps)(Amps)(Amps)(Amps)
ST3146755SS
3 Gbit mode
Table 4: ST373355SS DC power requirements
ST373355SS
1.5 Gbit mode
Notes
Voltage+5V+12V [2]+5V+12V [2]
Regulation[5]±5%±5% [2]±5%±5% [2]
Avg idle current DCX[1] [6]0.780.440.770.44
Maximum starting current
(peak DC) DC3σ[3]0.841.910.841.91
(peak AC) AC3σ[3]1.183.171.123.23
Delayed motor start (max) DC 3σ[1] [4]0.660.030.660.03
Peak operating current:
Typical DCX[1] 0.750.640.780.63
Maximum DC3σ[1]0.770.650.800.66
Maximum (peak) DC3σ1.502.321.542.32
0.15A DC and 0.2A AC 12V max start current margin added.
(Amps)(Amps)(Amps)(Amps)
ST373355SS
3 Gbit mode
[1]Measured with average reading DC ammeter or equivalent sampling scope. Instantaneous +12V current
peaks will exceed these values. Power supply at nominal voltage. N (number of drives tested) = 6, 35
24Cheetah T10 SAS Product Manual, Rev. A
Degrees C ambient.
[2]For +12 V, a –10% tolerance is allowed during initial spindle start but must return to ±5% before reaching
15,000 RPM. The ±5% must be maintained after the drive signifies that its power-up sequence has been
completed and that the drive is able to accept selection by the host initiator.
[3]See +12V current profile in Figures 2, 3, and 4.
[4]This condition occurs after OOB and Speed Negotiation completes but before the drive has received the
Notify Spinup primitive.
[5]See paragraph 6.2.1, "Conducted noise immunity." Specified voltage tolerance includes ripple, noise, and
transient response.
[6]During idle, the drive heads are relocated every 60 seconds to a random location within the band from
three-quarters to maximum track.
General DC power requirement notes.
1. Minimum current loading for each supply vo ltage is not less than 1.7% of the maximum operating current
shown.
2. The +5V and +12V supplies should employ separate ground returns.
3. Where power is provided to multiple drives from a common supply, careful consideration for individual
drive power requirements should be noted. Where multiple units are powered on simultaneously, the peak
starting current must be available to each device.
4. Parameters, other than spindle start, are measured after a 10-minute warm up.
5. No terminator power.
6.2.1Conducted noise immunity
Noise is specified as a periodic and random distribution of frequencies covering a band from DC to 10 MHz.
Maximum allowed noise values given below are peak-to-peak measurements and apply at the drive power
connector.
+5V+12V
0 to 100 kHz150mV150mV
100 kHz to 10 MHz100mV100mV
6.2.2Power sequencing
The drive does not require power sequencing. The drive protects against inadvertent writing during power-up
and down.
6.2.3Current profiles
The +12V and +5V current profiles for these drive are shown below in the following figures.
Note: All times and currents are typical. See Tables 2, 3, and 4 for maximum current requirements.
Cheetah T10 SAS Product Manual, Rev. A25
Figure 2. Typical ST3300555SS drive current profiles
26Cheetah T10 SAS Product Manual, Rev. A
Figure 3. Typical ST3146755SS drive current profiles
Cheetah T10 SAS Product Manual, Rev. A27
Figure 4. Typical ST373355SS drive current profiles
28Cheetah T10 SAS Product Manual, Rev. A
6.3Power dissipation
ST3300555SS in 3 Gbit operation
Typical power dissipation under idle conditions in 3Gb operation is 14.22 watts (48.52 BTUs per hour).
To obtain operating power for typical random read operations, refer to the following I/O rate curve (see Figure
5). Locate the typical I/O rate fo r a drive in you r system on the horizontal axis and read the corresponding +5
volt current, +12 volt current, and total watts on the vertical axis. To calculate BTUs per hour, multiply watts by
3.4123.
CURRENT/POWER vs THROUGHPUT (SAS - 3.0GB)
1.400
1.200
1.000
0.800
0.600
Amperes
0.400
0.200
0.000
0.050.0100.0150.0200.0250.0300. 0
Random 8 Block Reads
18. 0 0
16. 0 0
14. 0 0
12. 0 0
10. 0 0
8.00
6.00
4.00
2.00
0.00
5Volt A
12 V o l t A
Watts
Power (watts)
I/Os per Second
Figure 5. ST3300555SS (3 Gbit) DC current and power vs. input/output operations per second
ST3300555SS in 1.5 Gbit operation
Typical power dissipation under idle conditions in 1.5 Gbit oper ation is 14.15 watts (48.28 BTUs per hour).
To obtain operating power for typical random read operations, refer to the following I/O rate curve (see Figure
5). Locate the typical I/O rate fo r a drive in you r system on the horizontal axis and read the corresponding +5
volt current, +12 volt current, and total watts on the vertical axis. To calculate BTUs per hour, multiply watts by
3.4123.
CURRENT/POWER vs THROUGHPUT (SAS - 1.5GB)
1.4 0 0
1.2 0 0
1.0 0 0
0.800
0.600
Amperes
0.400
0.200
0.000
0.050.0100.0150.0200.0250.0300.0
Random 8 Block Reads
I/Os per Second
18 .0 0
16 .0 0
14 .0 0
12 .0 0
10 .0 0
8.00
6.00
4.00
2.00
0.00
5Volt A
12 V o l t A
Watts
Power (watts)
Figure 6. ST3300555SS (1.5 Gbit) DC current and power vs. input/output operations per second
Cheetah T10 SAS Product Manual, Rev. A29
ST3146755SS in 3 Gbit operation
Typical power dissipation under idle conditions in 3Gb operation is 10.74 watts (36.65 BTUs per hour).
To obtain operating power for typical random read operations, refer to the following I/O rate curve (see Figure
5). Locate the typical I/O rate for a drive in you r system on the horizontal axis and read the corresponding +5
volt current, +12 volt current, and total watts on the vertical axis. To calculate BTUs per hour, multiply watts by
3.4123.
CURRENT/POWER vs THROUGHPUT (SAS - 3.0GB)
1.4 0 0
1.2 0 0
1.0 0 0
0.800
0.600
Amperes
0.400
0.200
0.000
0.050.0100.0150.0200.0250.0300.0
Random 8 Block Reads
14 . 0 0
12 . 0 0
10 . 0 0
8.00
6.00
4.00
2.00
0.00
5Volt A
12 V o l t A
Watts
Power (watts)
I/Os per Second
Figure 7. ST3146755SS (3 Gbit) DC current and power vs. input/output operations per second
ST3146755SS in 1.5 Gbit operation
Typical power dissipation under idle conditions in 1.5 Gbit operation is 10.84 watts (36.99 BTUs per hour).
To obtain operating power for typical random read operations, refer to the following I/O rate curve (see Figure
5). Locate the typical I/O rate for a drive in you r system on the horizontal axis and read the corresponding +5
volt current, +12 volt current, and total watts on the vertical axis. To calculate BTUs per hour, multiply watts by
3.4123.
CURRENT/POWER vs THROUGHPUT (SAS - 1.5GB)
1.400
1.200
1.000
0.800
0.600
Amperes
0.400
0.200
0.000
0.050.0100.0150.0200.0250.0300.0
Random 8 Block Reads
14 . 0 0
12 . 0 0
10 . 0 0
8.00
6.00
4.00
2.00
0.00
5Volt A
12 V o l t A
Watts
Power (watts)
I/Os per Second
Figure 8. ST3146755SS (1.5 Gbit) DC current and power vs. input/output operations per second
30Cheetah T10 SAS Product Manual, Rev. A
ST373355SS in 3 Gbit operation
Typical power dissipation under idle conditions in 3Gb operation is 9.13 watts (31.15 BTUs per hour).
To obtain operating power for typical random read operations, refer to the following I/O rate curve (see Figure
5). Locate the typical I/O rate fo r a drive in you r system on the horizontal axis and read the corresponding +5
volt current, +12 volt current, and total watts on the vertical axis. To calculate BTUs per hour, multiply watts by
3.4123.
CURRENT/POWER vs THROUGHPUT (SAS - 3.0GB)
1.4 0 0
1.2 0 0
1.0 0 0
0.800
0.600
Amperes
0.400
0.200
0.000
0.050.0100.0150.0200.0250.0300.0
Random 8 Block Reads
14 . 0 0
12 . 0 0
10 . 0 0
8.00
6.00
4.00
2.00
0.00
5Volt A
12 V o l t A
Watts
Power (watts)
I/Os per Second
Figure 9. ST373355SS (3 Gbit) DC current and power vs. input/output operations per second
ST373355SS in 1.5 Gbit operation
Typical power dissipation under idle conditions in 1.5 Gbit operation is 9.18 watts (31.32 BTUs per hour).
To obtain operating power for typical random read operations, refer to the following I/O rate curve (see Figure
5). Locate the typical I/O rate fo r a drive in you r system on the horizontal axis and read the corresponding +5
volt current, +12 volt current, and total watts on the vertical axis. To calculate BTUs per hour, multiply watts by
3.4123.
CURRENT/POWER vs THROUGHPUT (SAS - 1.5GB)
1.400
1.200
1.000
0.800
0.600
Amperes
0.400
0.200
0.000
0.050.0100.0150.0200.0250.0300.0
Random 8 Block Reads
14. 0 0
12. 0 0
10. 0 0
8.00
6.00
4.00
2.00
0.00
5Volt A
12 V o l t A
Watts
Power (watts)
I/Os per Second
Figure 10. ST373355SS (1.5 Gbit) DC current and power vs. input/output operations per second
Cheetah T10 SAS Product Manual, Rev. A31
6.4Environmental limits
Temperature and humidity values experienced by the drive must be such that condensation does not occur on
any drive part. Altitude and atmospheric pressure specifications are referenced to a standard day at 58.7°F
(14.8°C). Maximum wet bulb temperature is 82°F (28°C).
6.4.1Temperature
a. Operating
The maximum allowable continuous or sustained HDA case temperature for the rated MTBF is 122°F
(50°C) The maximum allowable HDA case temperature is 60°C. Occasiona l excursions of HDA case tem
peratures above 122°F (50°C) or below 41°F (5°C) may occur without impact to specified MTBF. Continual
or sustained operation at HDA case temperatures outside these limits may degrade MTBF.
Provided the HDA case temperatures limits are met, the drive meets all specifications over a 41°F to 131°F
(5°C to 55°C) drive ambient temperature range with a maximum temperature gradient of 36°F (20°C) per
hour. Air flow m ay be needed in the dr ive enclosure to keep within this range (see Section 8.3). Operation at
HDA case temperatures outside this range may adversely affect the drives ability to meet specifications. To
confirm that the required cooling for the electronics and HDA case is provided, place the drive in its final
mechanical configuration, perform random write/read operations and measure the HDA case temperature
after it has stabilized.
b. Non-operating
–40° to 158°F (–40° to 70°C) package ambient with a maximum gradient of 36°F (20°C) per hour. This
specification assumes that the drive is packaged in the shipping cont ainer designe d by Seagate for use with
drive.
-
HDA Temp.
Check Point
Figure 11. Location of the HDA temper ature check point
1.0"
.5"
32Cheetah T10 SAS Product Manual, Rev. A
6.4.2Relative humidity
The values below assume that no condensation on the drive occurs.
a. Operating
5% to 95% non-condensing relative humidity with a maximum gradient of 20% per hour.
b. Non-operating
5% to 95% non-condensing relative humidity.
6.4.3Effective altitude (sea level)
a. Operating
–1,000 to +10,000 feet (–305 to +3,048 meters)
b. Non-operating
–1,000 to +40,000 feet (–305 to +12,210 meters)
6.4.4Shock and vibration
Shock and vibration limits specified in this document are measured directly on the drive chassis. If the drive is
installed in an enclosure to which the stated shock and/or vibration criteria is applied, resona nces may occur
internally to the enclosure resulting in drive movement in excess of the stated limits. If this situation is apparent,
it may be necessary to modify the enclosure to minimize drive movement.
The limits of shock and vibration defined within this document are specified with the drive mounted by any of
the four methods shown in Figure
12, and in accordance with the restrictions of Section 8.3.
6.4.4.1Shock
a. Operating—normal
The drive, as installed for normal operation, shall oper ate error free while subjected to intermittent shoc k not
exceeding 15 Gs at a maximum duration of 11 msec (half sinewave). The drive, as installed for normal
operation, shall operate error free while subjected to intermittent shock not exceeding 60 Gs at a maximum
duration of 2 msec (half sinewave). Shock may be applied in the X, Y, or Z axis.
b. Operating—abnormal
Equipment, as installed for normal operation, does not incur physical damage while subjected to intermittent shock not exceeding 40 Gs at a maximum duration of 11 msec (half sinewave). Shock occurring at
abnormal levels may promote degraded operational performa nce during the abnormal shock period. Speci
fied operational performance will continue when normal operating shock levels resume. Shock may be
applied in the X, Y, or Z axis. Shock is not to be repeated more than two times per second.
c. Non-operating
The limits of non-operating shock shall apply to all conditions of handling and transportation. This includes
both isolated drives and integrated drives.
The drive subjected to nonrepetitive shock not exceeding 75 Gs at a maximum duration of 11 msec (half
sinewave) shall not exhibit device damage or performance degradation. Shock may be applied in the X, Y,
or Z axis.
The drive subjected to nonrepetitive shock not exceeding 250 Gs at a maximum duration of 2 msec (half
sinewave) does not exhibit device damage or performance degradation. Shock may be applied in the X, Y,
or Z axis.
The drive subjected to nonrepetitve shock not exceeding 120 Gs at a maximum duration of 0.5 msec (half
sinewave) does not exhibit device damage or performance degradation. Shock may be applied in the X, Y,
or Z axis.
-
Cheetah T10 SAS Product Manual, Rev. A33
d. Packaged
Disc drives shipped as loose load (not palletized) general freight will be packaged to withstand drops from
heights as defined in the table below. For additional details refer to Seagate specifications 30190-001
(under 100 lbs/45 kg) or 30191-001 (over 100 lbs/45 Kg).
Package sizePackaged/product weightDrop height
<600 cu in (<9,800 cu cm)Any60 in (1524 mm)
600-1800 cu in (9,800-19,700 cu cm)0-20 lb (0 to 9.1 kg)48 in (1219 mm)
>1800 cu in (>19,700 cu cm)0-20 lb (0 to 9.1 kg)42 in (1067 mm)
>600 cu in (>9,800 cu cm)20-40 lb (9.1 to 18.1 kg)36 in (914 mm)
Drives packaged in single or multipacks with a gross weight of 20 pounds (8.95 kg) or less by Seagate for
general freight shipment shall withstand a drop test from 48 inches (1,070 mm) against a concrete floor or
equivalent.
Z
Y
X
Figure 12. Recommended mounting
X
Y
Z
34Cheetah T10 SAS Product Manual, Rev. A
6.4.4.2Vibration
a. Operating—normal
The drive as installed for normal operation, shall comply with the complete specified performance while
subjected to continuous vibration not exceeding
10-500 Hz @ 0.5 G (zero to peak)
Vibration may be applied in the X, Y, or Z axis.
Operating normal translational random flat profile
10 - 500 Hz0.4 gRMS
b. Operating—abnormal
Equipment as installed for normal operation shall not incur physical damage while subjected to periodic
vibration not exceeding:
15 minutes of duration at major resonant frequency
10-500 Hz @ 0.75 G (X, Y, or Z axis)
Vibration occurring at these levels may degrade operational performance during the abnormal vibration
period. Specified operational performance will continue when normal operating vibration levels are
resumed. This assumes system recovery routines are available.
Operating abnormal translational random flat profile
10 - 500 Hz1.2 gRMS
c. Non-operating
The limits of non-operating vibration shall apply to all conditions of handling and transportation. This
includes both isolated drives and integrated drives.
The drive shall not incur physical damage or degraded performance as a result of continuous vibration not
exceeding
Vibration may be applied in the X, Y, or Z axis.
Non-operating translational random flat profile
The drive is designed to operate in a typical office environment with minimal environmental control.
6.4.6Corrosive environment
Seagate electronic drive components pass accelerated corrosion testing equivalent to 10 years exposure to
light industrial environments containing sulfurous gases, chlorine and nitric oxide, classes G and H per ASTM
B845. However, this accelerated testing cannot duplicate every potential application environment.
Users should use caution exposing any electronic components to uncontrolled chemical pollutants and corrosive chemicals as electronic drive component reliability can be affected by the installationenvironment. The silver, copper, nickel and gold films used in Seagate products are especially sensitive to the presence of sulfide,
chloride, and nitrate contaminants. Sulfur is found to be the most da maging. In addi tion, electronic comp onent s
should never be exposed to condensing water on the surface of the printed circuit board assembly (PCBA) or
exposed to an ambient relative humidity greater than 95%. Materials used in cabinet fabrication, such as vulca
nized rubber, that can outgas corrosive compounds should be minimized or eliminated. The useful life of any
electronic equipment may be extended by replacing materials near circuitry with sulfide-free alternatives.
Cheetah T10 SAS Product Manual, Rev. A35
-
6.4.7Acoustics
Sound power during idle mode shall be 3.6 bels typical when measured to ISO 7779 specification. Sound
power while operating shall be 4.3 bels typical when measured to ISO 7779 specification.
There will not be any discrete tones more than 10 dB above the masking noise on typical drives when measured according to Seagate specification 30553-001. There will not be any tones more than 24 dB above the
masking noise on any drive.
6.4.8Electromagnetic susceptibility
See Section 2.1.1.1.
6.5Mechanical specifications
Refer to Figure 13 for detailed physical dimensions. See Section 8.3, “Drive mounting.”
Height:1.028 in26.11 mm
Width:4.010 in101.85 mm
Depth:5.787 in146.99 mm
Weight:1.85 pounds0.839 kilograms
50.80
(2.000)
UNITS OF MEASURE: mm (inches)
20.14
(.793)
101.60 +/- .25
(4.000 +/- .010)
2X 100.13
(2X 3.942)
26.11 MAX
(1.028 MAX)
98.42
(3.875)
33.40
(1.315)
2X 20.14
(2X .793)
1.45 (.057)
20.68 (.814)
0.76
( .030)
6.35 (.250)
3.17 (.125)
24.00
(.945)
2X 28.45
(2X 1.120)
41.15 (1.620)
2X 29.21
(2X 1.150)
2X 70.05 (2X 2.758)
85.60 (3.370)
122.00 (4.803)
2X 130.05 (2X 5.120)
146.99 MAX (5.787 MAX)
131.17 (5.164)
4.22 X 90 ( .166 X 90 )
0.36
( .014)
4.57 MIN BLIND
( .18 MIN BLIND)
4.22 X 90 ( .166 X 90 )
0.36
( .014)
DRIVE
CENTER
LINE
0.13
3.50 +/- .38
(.138 +/- .015)
0.25
(.010)
(.005)
0.13
(.005)
0.99
(.039)
0.41
(.016)
36.37
(1.432)
Figure 13. Physical dimensions
36Cheetah T10 SAS Product Manual, Rev. A
7.0Defect and error management
Seagate continues to use innovative technologies to manage defects and errors. These technologies are
designed to increase data integrity, perform drive self-maintenance, and validate proper drive operation.
SCSI defect and error managemen t involves drive internal defect/error management and SAS system error
considerations (errors in communications between the initiator and the drive). In addition, Seagate provides
the following technologies used to increase data integrity and drive reliability:
• Background Media Scan (see Section 7.4)
• Media Pre-Scan (see Section 7.5)
• Deferred Auto-Reallocation (see Section 7.6)
• Idle Read After Write (see Section 7.7)
The read error rates and specified storage capacities are not dependent on host (initiator) defect management
routines.
7.1Drive internal defects/errors
During the initial drive format operation at the factory, media defects are identified, tagged as being unusable,
and their locations recorded on the drive primary defects list (referred to as the “P’ list and also as the ETF
defect list). At factory format time, these known defects are also reallocated, that is, reassigned to a new place
on the medium and the location liste d in the defects reallocation table. The “P” list is not altered after factory
formatting. Locations of defects found and reallocated during error recovery procedures after drive shipment
are listed in the “G” list (defects growth list). The “P” and “G” lists may be referenced by the initiator using the
Read Defect Data command.
Details of the SCSI commands supported by the drive are described in the SAS Interface Manual. Also, more
information on the drive Error Recovery philosophy is presented in the SAS Interface Manual.
7.2Drive error recovery procedures
When an error occurs during drive operation, the drive, if pr ogrammed to do so, p erforms err or recovery procedures to attempt to recover the dat a . The erro r reco very pro cedures us ed depen d on the o ptions prev iously set
in the Error Recovery Parameters mode page. Error recovery and defect management may involve using sev
eral SCSI commands described in the SAS Interface Manual. The drive implements selectable error recovery
time limits required in video applications.
The error recovery scheme supported by the drive provides a way to control the to tal error r ecovery time for the
entire command in addition to controlling the recovery level for a single LBA. The total amount of time spent in
error recovery for a command can be limited using the Recovery Time Limit bytes in the Error Recovery mode
page. The total amount of time spent in error recovery for a single LBA can be limited using the Read Retry
Count or Write Retry Count bytes in the Error Recovery mode page.
Cheetah T10 SAS Product Manual, Rev. A37
-
The drive firmware error recovery algorithms consists of 11 levels for read recoveries and five levels for write.
Each level may consist of multiple steps, where a step is defined as a recovery function involving a single reread or re-write attempt. The maximum level used by the drive in LBA recovery is determined by the read and
write retry counts.
Table 5 equates the read and write retry count with the maximum possible recovery time for read and write
recovery of individual LBAs. The times given do not include time taken to perform reallocations. Reallocations
are performed when the ARRE bit (for reads) or AWRE bit (for writes) is one, the RC bit is zero, and the recov
ery time limit for the command has not yet been met. Time needed to perform reallocation is not counted
against the recovery time limit.
When the RC bit is one, reallocations are disabled even if the ARRE or AWRE bits are one. The drive will still
perform data recovery actions within the limits defined by the Read Retry Count, Write Retry Count, and
Recovery Time Limit parameters. However, the drive does not report any unrecovered errors.
Table 5: Read and write retry count maximum recovery times
Setting these retry counts to a value below the default setting could result in degradation of the unrecovered error rate which may exceed the value given in this product manual. A setting of zero (0) will result in
the drive not performing error recovery.
For example, suppose the read/write recovery page has the RC bit set to 0, read retry count set to 4, and
the recovery time limit field (Mode Sense page 01, bytes 10 and 11) set to FF FF hex (maximum). A four
LBA Read command is allowed to take up to 253.11 msec recovery time for each of the four LBAs in the
command. If the recovery time limit is set to 00 C8 hex (200 msec decimal) a four LBA read command is
allowed to take up to 200 msec for all error recovery within that command. The use of the Recovery Time
Limit field allows finer granularity on control of the time spent in error recovery. The recovery time limit
only starts counting when the drive is executing error recovery and it restarts on each command. There
fore, each command’s total recovery time is subject to the recovery time limit. Note: A recovery time limit
of 0 will use the drive’s default value of FF FF. Minimum recovery time limit is achieved by setting the
Recovery Time Limit field to 00 01.
-
38Cheetah T10 SAS Product Manual, Rev. A
7.3SAS system errors
Information on the reporting of operational errors or faults across the interface is given in the SAS Interface
Manual. The SSP Response returns information to the host about numerous kinds of errors or faults. The
Receive Diagnostic Results reports the results of diagnostic operations performed by the drive.
Status returned by the drive to the initiator is described in the SAS Interface Manual. Status reporting plays a
role in systems error management and its use in that respect is described in sections where the various com
mands are discussed.
7.4Background Media Scan
Background Media Scan (BMS) is a self-initiated media scan. BMS is defined in the T10 document SPC-4
available from the T10 committee. BMS performs sequential reads across the entire pack of the media while
the drive is idle. In RAID arrays, BMS allows hot spare drives to be scann ed for defects prior to being pu t into
service by the host system. On regular duty drives, if the host system makes use of the BMS Log Page, it can
avoid placing data in suspect locations on the media. Unreadable and recovered error sites will be logged or
reallocated per ARRE/AWRE settings.
With BMS, the host system can consume less power and system overhead by only checking BMS status and
results rather than tying up the bus and consuming power in the process of host-i nitiated media scan ning activ
ity.
Since the background scan functions are only done dur ing idle periods, BMS ca uses a negligible imp act to system performance. The first BMS scan for a newly manufactured drive is performed as quickly as possible to
verify the media and protect data by setting the “Start time after idle” to 5ms, all subsequent scans begin after
500ms of idle time. Other features that normally use idle time to function will function normally because BMS
functions for bursts of 800ms and then suspends activity for 100ms to allow other background functions to
operate.
-
-
BMS interrupts immediately to service host commands from the interface bus while performing reads. BMS will
complete any BMS-initiated error recovery prior to returning to service host-initiated commands. Overhead
associated with a return to host-servicing activity from BMS only impacts the first command that interrupted
BMS, this results in a typical delay of about 1 ms.
7.5Media Pre-Scan
Media Pre-Scan is a feature that allows the drive to repair media errors that would otherwise have been found
by the host system during critical data accesses early in the drive’s life. The default setting for Media Pre-Scan
is enabled on standard products. Media Pre-Scan checks each write command to determine if the destination
LBAs have been scanned by BMS. If the LBAs have been verified, the drive proceeds with the normal write
command. If the LBAs have not been verified by BMS, Pre-Scan will convert the write to a write verify to certify
that the data was properly written to the disc.
Note.During Pre-Scan write verify commands, write performance may decrease by 50% un til Pre-Scan
completes. Write performance testing shou ld be performed after Pre-Scan is complete. Th is may
be checked by reading the BMS status.
To expedite the scan of the full pack and subsequently exit from the Pre-Scan period, BMS will begin scanning
immediately when the drive goes to idle during the Pre-Scan period. In the event that the drive is in a high
transaction traffic environment and is unable to complete a BMS scan within 24 power on hours BMS will dis
able Pre-Scan to restore full performance to the system.
-
Cheetah T10 SAS Product Manual, Rev. A39
7.6Deferred Auto-Reallocation
Deferred Auto-Reallocation (DAR) simplifies reallocation algorithms at the system level by allowing the drive to
reallocate unreadable locations on a subsequent write command. Sites are marked for DAR during read oper
ations performed by the drive. When a write command is received for an LBA marked for DAR, the auto-reallocation process is invoked and attempts to rewrite the data to the original location. If a verification of this rewrite
fails, the sector is re-mapped to a spare location.
This is in contrast to the system having to use the Reassign Command to reassign a location that was unreadable and then generate a write command to rewrite the data. DAR is most effective when AWRE and ARRE
are enabled—this is the default setting from the Seagate factory. With AWRE and ARRE disabled DAR is
unable to reallocate the failing location and will report an error sense code indicating that a write command is
being attempted to a previously failing location.
7.7Idle Read After Write
Idle Read After Write (IRAW) utilizes idle time to verify the integrity of recently written data. During idle periods,
no active system requests, the drive reads recently written data from the media and compares it to valid write
command data resident in the drives data buffer. Any sector s that fail the co mparison result in the invocation of
a rewrite and auto-reallocation process. The process attempts to rewrite the data to the original location. If a
verification of this rewrite fails, the sector is re-mapped to a spare location.
-
40Cheetah T10 SAS Product Manual, Rev. A
8.0Installation
Cheetah disc drive installation is a plug-and-play process. There are no jumpers, switches, or terminators on
the drive.
SAS drives are designed to be used in a host system that provides a SAS-compatible backplane with bays
designed to accomodate the drive. In such systems, the host system typically provides a carrier or tray into
which you need to mount the drive. Mount the drive to the carrier or tray provided by the host system using four
6-32 UNC screws. Do not over-tighten or force the screws. You can mount the drive in any orientation.
Note.SAS drives are designed to be attached to the host system without I/O or power cables. If you
intend the use the drive in a non-backplane host system, connecting the drive using high-quality
cables is acceptable as long as the I/O cable length does not exceed 4 meters (13.1 feet).
Slide the carrier or tray into the appropriate bay in your host system using the instructions provided by the host
system. This connects the drive directly to your system’s SAS connector. The SAS connector is normally
located on a SAS backpanel. See
Power is supplied through the SAS connector.
The drive is shipped from the factory low-level formatted in 512-byte logical blocks. You need to reformat the
drive only if you want to select a different logical block size.
Section 9.4.1 for additional information about these connectors.
SAS Interface
connector
Figure 14. Physical interface
8.1Drive orientation
The drive may be mounted in any orientation. All drive performance characterizations, however, have been
done with the drive in horizontal (discs level) and vertical (drive on its side) orientations, which are the two pre
ferred mounting orientations.
Cheetah T10 SAS Product Manual, Rev. A41
-
8.2Cooling
Cabinet cooling must be designed by the customer so that the ambient temperature immediately surro unding
the drive will not exceed temperature conditions specified in
The rack, cabinet, or drawer environment for the drive must provide heat removal from the electronics and
head and disc assembly (HDA). You should confirm that adequate heat removal is provided using the temper
ature measurement guidelines described in Section 6.4.1.
Forced air flow may be r equired to keep temper atures a t or be low the t emperat ures spe cified in S ection 6.4.1
in which case the drive should be oriented, or air flow directed, so that the least amount of air flow resistance is
created while providing air flow to the electronics and HDA. Also, the shortest possible path between the air
inlet and exit should be chosen to minimize the travel length of air heated by the drive and other heat sources
within the rack, cabinet, or drawer environment.
If forced air is determined to be necessary, possible air-flow patterns are shown in Figure 15. The air-flow patterns are created by one or more fans, either forcing or drawing air as shown in the illustrations. Conduction,
convection, or other forced air-flow patterns are acceptable as long as the temperature measurement guide
lines of Section 6.4.1 are met.
Section 6.4.1, "Temperature."
-
-
Note. Air flows in the direction shown (back to front)
or in reverse direction (front to back)
Note. Air flows in the direction shown or
in reverse direction (side to side)
Figure 15. Air flow
Above unit
Under unit
Above unit
Under unit
42Cheetah T10 SAS Product Manual, Rev. A
8.3Drive mounting
Mount the drive using the bottom or side mounting holes . If you mount the drive using the b ottom holes, ensure
that you do not physically distort the drive by attempting to mount it on a stiff, non-flat surface.
The allowable mounting surface stiffness is 80 lb/in (14.0 N/mm) . The followin g equation and paragraph define
the allowable mounting surface stiffness:
K x X = F < 15lb = 67N
where K is the mounting surface stiffness (units in lb/in or N/mm) and X is the out-of-plane surface distortion
(units in inches or millimeters). The out-of-plane distortion (X) is determined by defining a plane with three of
the four mounting points fixed and evaluating the out-of-plane deflection of the fourth mounting point when a
known force (F) is applied to the fourth point.
8.4Grounding
Signal ground (PCBA) and HDA ground are connected together in the drive and cannot be separated by the
user. The equipment in which the drive is mounted is connected directly to the HDA and PCBA with no ele ctri
cally isolating shock mounts. If it is desired for the system chassis to not be connected to the HDA/PCBA
ground, the systems integrator or user must provide a nonconductive (electrically isolating) method of mount
ing the drive in the host equipment.
Increased radiated emissions may result if you do not provide the maximum surface area ground connection
between system ground and drive ground. This is the system designer’s and integrator’s responsibility.
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Cheetah T10 SAS Product Manual, Rev. A43
44Cheetah T10 SAS Product Manual, Rev. A
9.0Interface requirements
This section partially describes the interface requirements as implemented on Cheetah drives. Additional information is provided in the SAS Interface Manual (part number 100293071).
9.1SAS features
This section lists the SAS-specific features supported by Cheetah drives.
9.1.1 task management functions
Table 6 lists the SAS task management functions supported.
Table 7 lists the SAS response codes returned for task management functions supported.
Table 7: Task management response codes
Function nameResponse co de
Function complete00
Invalid frame02
Function not supported04
Function failed05
Function succeeded08
Invalid logical unit09
Cheetah T10 SAS Product Manual, Rev. A45
9.2Dual port support
Cheetah SAS drives have two independent ports. These ports may be connected in the same or dif ferent SCSI
domains. Each drive port has a unique SAS address.
The two ports run at the same link rate. The first port to successfully complete speed negotiation sets the link
rate support by both ports. When the second port participates in speed negotiation, it indicates the only sup
ported speed is the speed selected by the first port. If the first port to complete speed negotiation looses sync
before the second port completes speed negotiation, both ports revert back to the power on condition of allow
ing either link rate (1.5 or 3.0 Gbits/sec).
Subject to buffer availability, the Cheetah drives support:
• Concurrent port transfers—The drive supports receiving COMMAND, TASK management transfers on both
ports at the same time.
• Full duplex—The drive supports sending XFER_RDY, DATA and RESPONSE transfers while receiving
frames on both ports.
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46Cheetah T10 SAS Product Manual, Rev. A
9.3SCSI commands supported
Table 8 lists the SCSI commands supported by Cheetah drives.
Table 8: Commands supported by Cheetah T10 SAS family drives
Command nameCommand codeSupported
Change Definition40hN
Compare39hN
Copy18hN
Copy and Verify3AhN
Format Unit [1]04hY
DPRY bit supportedN
DCRT bit supportedY
STPF bit supportedY
IP bit supportedY
DSP bit supportedY
IMMED bit supportedY
VS (vendor specific)N
Inquiry12hY
Date Code page (C1h)Y
Device Behavior page (C3h)Y
Firmware Numbers page (C0h)Y
Implemented Operating Def page (81h)Y
Jumper Settings page (C2h)Y
Supported Vital Product Data page (00h)Y
Unit Serial Number page (80h)Y
Lock-unlock cache36hN
Log Select4ChY
PCR bitY
DU bitN
DS bitY
TSD bitY
ETC bitN
TMC bitN
LP bitN
Log Sense4DhY
Application Client Log page (0Fh)Y
Buffer Over-run/Under-run page (01h)N
Cache Statistics page (37h)Y
Factory Log page (3Eh)Y
Last n Deferred Errors or Asynchronous Events page (0Bh)N
Last n Error Events page (07h)N
Cheetah T10 SAS Product Manual, Rev. A47
Table 8: Commands supported by Cheetah T10 SAS family drives (continued)
Command nameCommand codeSupported
Non-medium Error page (06h)Y
Pages Supported list (00h)Y
Read Error Counter page (03h)Y
Read Reverse Error Counter page (04h)N
Self-test Results page (10h)Y
Background Medium Scan page (15h)Y
Start-stop Cycle Counter page (0Eh)Y
Temperature page (0Dh)Y
Verify Error Counter page (05h)Y
Write error counter page (02h)Y
Mode Select (same pages as Mode Sense 1Ah)15hY [2]
Mode Select (10) (same pages as Mode Sense 1Ah)55hY
Mode Sense1AhY [2]
Caching Parameters page (08h)Y
Control Mode page (0Ah)Y
Disconnect/Reconnect (02h)Y
Error Recovery page (01h)Y
Format page (03h)Y
Information Exceptions Control page (1Ch)Y
Background Medium Scan mode subpage (01h)Y
Notch and Partition Page (0Ch)N
Protocol-Specific Port page (19h)Y
Power Condition page (1Ah)Y
Rigid Disc Drive Geometry page (04h)Y
Unit Attention page (00h)Y
Verify Error Recovery page (07h)Y
Xor Control page (10h)N
Mode Sense (10) (same pages as Mode Sense 1Ah)5AhY
Prefetch34hN
Read08hY
Read Buffer (modes 0, 2, 3, Ah and Bh supported)3ChY
Read Capacity25hY
Read Defect Data (10)37hY
Read Defect Data (12)B7hY
Read Extended28hY
DPO bit supportedY
FUA bit supportedY
Read Long3EhY
48Cheetah T10 SAS Product Manual, Rev. A
Table 8: Commands supported by Cheetah T10 SAS family drives (continued)
Command nameCommand codeSupported
Reassign Blocks07hY
Receive Diagnostic Results1ChY
Supported Diagnostics pages (00h)Y
Translate page (40h)Y
Release17hY
Release (10)57hY
Request Sense03hY
Actual Retry Count bytesY
Extended SenseY
Field Pointer bytesY
Reserve16hY
3rd Party ReserveY
Extent ReservationN
Reserve (10)56hY
3rd Party ReserveY
Extent ReservationN
Rezero Unit01hY
Search Data Equal31hN
Search Data High30hN
Search Data Low32hN
Seek0BhY
Seek Extended2BhY
Send Diagnostics1DhY
Supported Diagnostics pages (00h)Y
Translate page (40h)Y
Set Limits33hN
Star t Unit/Stop Unit (spindle ceases rotating)1BhY
Synchronize Cache35hY
Test Unit Ready00hY
Verify2FhY
BYTCHK bitY
Write0AhY
Write and Verify2EhY
DPO bitY
Write Buffer (modes 0, 2, supported)3BhY
Firmware Download option
[1]Cheetah drives can format to 512, 520, 524, or 528 bytes pe r logical block.
[2]Warning. Power loss during flash programming can result in firmware corruption. This usually makes the
drive inoperable.
[3]Reference Mode Sense command 1Ah for mode pages supported.
[4]Y = Yes. Command is supported.
N = No. Command is not supported.
A = Support is available on special request.
50Cheetah T10 SAS Product Manual, Rev. A
9.3.1Inquiry data
Table 9 lists the Inquiry command data that the drive should return to the initiator per the format given in the
SAS Interface Manual.
*Copyright year (changes with actual year).
**SCSI Revision support. See the appropriate SPC release documention for definitions.
PP 10 = Inquiry data for an Inquiry command received on Port A.
30 = Inquiry data for an Inquiry command received on Port B.
R# Four ASCII digits representing the last four digits of the product firmware relea s e number.
S#Eight ASCII digits representing the eight digits of the product serial number.
[ ]Bytes 16 through 26 reflect model of drive. The table above shows the hex values for Model ST3300555SS.
Refer to the values below for the values of bytes 16 through 26 of your particular model:
ST3300555SS53 54 33 33 30 30 35 35 35 53 53
ST3146755SS53 54 33 31 34 36 37 35 35 53 53
ST373355SS53 54 33 37 33 33 35 35 53 53 20
9.3.2Mode Sense data
The Mode Sense command provides a way for the drive to report its operating parameters to the initiator. The
drive maintains four sets of mode parameters:
1. Default values
Default values are hard-coded in the drive firmware stored in flash E-PROM (nonvolatile memory) on the
drive’s PCB. These default values can be changed only by downloading a complete set of new firmware
into the flash E-PROM. An initiator can request and receive from the drive a list of default values and use
those in a Mode Select command to set up new current and saved values, where the values are change
able.
2. Saved values
Saved values are stored on the drive’s media using a Mode Select command. Only parameter values that
are allowed to be changed can be changed by this method. Parameters in the saved values list that are not
changeable by the Mode Select command get their values from default values storage.
When power is applied to the drive, it takes saved values from the media and stores them as current values in volatile memory. It is not possible to change the current values (or the saved values) with a Mode
Cheetah T10 SAS Product Manual, Rev. A51
-
Select command before the drive achieves operating speed and is “read y.” An attempt to do so results in a
“Check Condition” status.
On drives requiring unique saved values, the required unique saved values are stored into the saved values storage location on the media prior to shipping the drive. Some drives may have unique firmware with
unique default values also.
On standard OEM drives, the saved values are taken from the default values list and stored into the saved
values storage location on the media prior to shipping.
3. Current values
Current values are volatile values being used by the drive to control its operation. A Mode Select command
can be used to change the values identified as changeable values. Originally, current values are installed
from saved or default values after a power on reset, hard reset, or Bus Device Reset message.
4. Changeable values
Changeable values form a bit mask, stored in nonvolatile memory, that dictates which of the current values
and saved values can be changed by a Mode Select command. A one (1) indicates the value can be
changed. A zero (0) indicates the value is not changeable. For example, in Table
81, in the row entitled “CHG.” These are hex numbers representing the changeable values for Mode page
81. Note in columns 5 and 6 (bytes 04 and 05), there is 00h which indicates that in bytes 04 and 05 none of
the bits are changeable. Note also that bytes 06, 07, 09, 10, and 11 are not changeable, because those
fields are all zeros. In byte 02, hex value FF equates to the binary pattern 11111111. If there is a zero in any
bit position in the field, it means t hat bit is not changeable. Since all of the bits in byte 02 are ones, all of
these bits are changeable.
The changeable values list can only be changed by downloading new firmware into the flash E-PROM.
10, refer to Mode page
Note.Because there are often several different versions of drive control firmware in the total pop ulation of
drives in the field, the Mode Sense values given in the following tables may not exactly match those
of some drives.
The following tables list the values of the data bytes returned by the d rive in response to the Mode Sense command pages for SCSI implementation (see the SAS Interface Manual ).
Definitions:
DEF = Default value. Standard OEM drives are shipped configured this way.
CHG = Changeable bits; indicates if default value is changeable.
9.4Miscellaneous operating features and conditions
Table 13 lists various features and conditions. A “Y” in the support column indicates the feature or condition is
supported. An “N” in the support column indicates the feature or condition is not supported.
Table 13: Miscellaneous features
SupportedFeature or condi tio n
NAutomatic contingent allegiance
NAsynchronous event notification
NSynchronized (locked) spindle operation
YSegmented caching
NZero latency read
YQueue tagging (up to 64 queue tags supported)
YDeferred error handling
YParameter rounding (controlled by Round bit in Mode Select page 0)
YReporting actual retry count in Extended Sense bytes 15, 16, and 17
NAdaptive caching
YSMP = 1 in Mode Select command needed to save RPL and rotational offset bytes
Table 14: Miscellaneous status
SupportedStatus
YGood
YCheck condition
YCondition met/g ood
YBusy
YIntermediate/good
YIntermediate/conditi on met/good
YReservation conflict
YTask set full
NACA active
NACA active, faulted initiator
56Cheetah T10 SAS Product Manual, Rev. A
9.4.1SAS physical interface
Figure 16 shows the location of the SAS device connector J1. Figures 17 and 18 provide the dimensions of the
SAS device.
Details of the physical, electrical, and logical characteristics are provided within this section. The operational
aspects of Seagate’s SAS drives are provided in the SAS Interface Manual..
J6
SAS Interface
connector
Figure 16. Physical interface
Cheetah T10 SAS Product Manual, Rev. A57
0.80 (6X)
0.30 0.05 (2X)
4.00 0.08
0.15 D
2.00 (3X)
7.625.92
5.08
42.73 REF.
41.13 0.15
0.20
B
C
A
4.65
0.45 0.03 (7X)
0.10 M
E
0.52 0.08 x 45
B
1.10
C OF DATUM D
L
0.30 0.05 (4X)
0.35MIN
B
C
15.875
1.27 (14X)
P15
Figure 17. SAS connector dimensions
33.43 0.05
5.08
C OF DATUM B
L
A
15.875
1.27 (6X)
P1
R0.30 0.08 (4X)
SEE Detail1
B
0.84 0.05 (22X)
0.15 B
4.90 0.08
S1
S7
58Cheetah T10 SAS Product Manual, Rev. A
Detail A
SEE Detail 2
3.90 0.15
2.25 0.05
4.85 0.05
0.10 B
E
SECTION A - A
0.08 0.05
S14
6.10
4.40 0.15
0.35 0.05
CONTACT SURFACE FLUSH
TO DATUM A 0.03
S8
0.40 0.05 X 45 (3X)
CORING ALLOWED
IN THIS AREA.
A
0.30 0.05 x 45 (5X)
R0.30 0.08
45
SECTION C - C
C
1.95 0.08
1.23 0.05
65
30
Detail 2
0.08 0.05
2.40 0.08
0.10 A
SECTION B - B
D
1.90 0.08
Figure 18. SAS connector dimensions
9.4.2Physical characteristics
This section defines physical interface connector.
9.4.3Connector requirements
Contact your preferred connector manufacturer for mating part information. Part numbers for SAS connectors
will be provided in a future revision of this publication when production parts are available from major connec
tor manufacturers.
The SAS device connector is illustrated in Figures 17 and 18.
-
Cheetah T10 SAS Product Manual, Rev. A59
9.4.4Electrical description
SAS drives use the device connector for:
• DC power
• SAS interface
• Activity LED
This connector is designed to either plug directly into a backpanel or accept cables.
9.4.5Pin descriptions
This section provides a pin-out of the SAS device and a description of the functions provided by the pins.
Table 15: SAS pin descriptions
PinSignal nameSignal typePinSignal nameSignal type
S1Port A GroundP1*NC (reserved 3.3Volts)
S2*+Port A_inDiff. input pairP2*NC (reserved 3.3Volts)
S3*-Port A_inP3NC (reserved 3.3Volts)
S4Port A GroundP4Ground
S5*-Port A_outDiff output pairP5Ground
S6*+Port A_outP6Ground
S7Port A GroundP75 Volts charge
S8Port B GroundP8*5 Volts
S9*+Port B_inDiff. input pairP9*5 Volts
S10*-Port B_inP10Ground
S11Port A GroundP11*Ready LEDOpen collector out
S12*-Port B_outDiff output pairP12Ground
S13*+Port B_outP1312 Volts charge
S14Port B GroundP14*12 Volts
P15*12 Volts
* - Short pin to support hot plugging
NC - No connection in the drive.
60Cheetah T10 SAS Product Manual, Rev. A
9.4.6SAS transmitters and receivers
A typical SAS differential copper transmitter and receiver pair is shown in Figure 19. The receiver is AC coupling to eliminate ground shift noise.
TX
Transmitter
100
TY
Figure 19. SAS transmitters and receivers
Differential
Transfer Medium
.01
.01
RX
Receiver
100
RY
9.4.7Power
The drive receives power (+5 volts and +12 volts) through the SAS device connector.
Three +12 volt pins provide power to the drive, 2 short and 1 long. The current return for the +12 volt power
supply is through the common ground pins. The supply current and return current must be distributed as
evenly as possible among the pins.
Three +5 volt pins provide power to the drive , 2 short and 1 long. The current return for the +5 volt power supply is through the common ground pins. The supply curre nt and retu rn current must be distributed as evenly as
possible among the pins.
Current to the drive through the long power pins may be limited by the system to reduce inrush current to the
drive during hot plugging.
9.5Signal characteristics
This section describes the electrical signal characteristics of the drive’s input and output signals. See Tab le 15
for signal type and signal name information.
9.5.1Ready LED Out
The Ready LED Out signal is driven by the drive as indicated in Table 16.
Table 16: Ready LED Out conditions
Normal command activityLED status
Ready LED Meaning bit mode page 19h
Spun down and no activityOffOff
Spun down and activity (command executing)OnOn
Spun up and no activityOnOff
Spun up and activity (command executing)OffOn
Spinni ng up or downBlinks steadily
(50% on and 50% off, 0.5 seconds on and off for 0.5 seconds)
Format in progress, each cylinder changeToggles on/off
01
Cheetah T10 SAS Product Manual, Rev. A61
The Ready LED Out signal is designed to pull down the cathode of an LED. The anode is attached to the
proper +3.3 volt supply through an appr opri ate c urren t limitin g re sistor. The LED and the curr ent lim iting re sis
tor are external to the drive. See Table 17 for the output characteristics of the LED drive signals.
Table 17: LED drive signal
StateTest conditionOutput voltage
LED off, high0 V ≤ VOH ≤ 3.6 V-100 µA < IOH < 100 µA
LED on, lowIOL = 15 mA0 ≤ VOL ≤ 0.225 V
9.5.2Differential signals
The drive SAS differential signals comply with the intra-enclosure (internal connector) requirements of the SAS
standard.
Table 18 defines the general interface characteristics.
Table 18: General interface characteristics
CharacteristicUnits1.5 Gbps3.0 Gbps
Bit rate (nominal)Mbaud1,5003,000
Unit interval (UI)(nominal)ps666.6333.3
Impedance (nominal, differential )ohm100100
Transmitter transients, maximumV± 1.2± 1.2
Receiver transients, maximumV± 1.2± 1.2
-
9.5.2.1Eye masks
9.5.2.1.1Eye masks overview
The eye masks are graphical representations of the voltage and time limits on the signal at the compliance
point. The time values between X1 and (1 - X1) cover all but 10
-12
of the jitter population. The random content
of the total jitter population has a range of ± 7 standard deviations.
62Cheetah T10 SAS Product Manual, Rev. A
9.5.2.1.2Receive eye mask
Figure 20 describes the receive eye mask. This eye mask applies to jitter after the application of a single pole
high-pass frequency-weighting function that progressively attenuates jitter at 20 dB/decade below a frequency
of ((bit rate) / 1.667).
Absolute
amplitude
(in V)
Z2
Z1
0 V
-Z1
-Z2
01
X1X2
Norm alize d time (in UI)
Figure 20. Receive eye mask
1-X1
1-X2
Verifying compliance with the limits represented by the receive eye mask should be done with reverse channel
traffic present in order that the effects of crosstalk are taken into account.
9.5.2.1.3Jitter tolerance masks
Figure 21 describes the receive tolerance eye masks and is constructed using the X2 and Z2 values given in
table 21. X1OP is half the value for total jitter intable 21 and X1
is half the value for total jitter in table 22, for
TOL
jitter frequencies above ((bit rate) / 1.667).
Absolute
amplitude
(in V)
Z2
Z1
OP
Z1
TOL
0 V
-Z1
TOL
-Z1
OP
-Z2
X1
01
OP
X1
TOL
Normalized time (in UI)
(additional sinusoidal jitter) / 2
X2
1-X1
OP
1-X1
TOL
Outline of eye mask
before adding
sinusoidal jitter
Outline of eye mask
after adding
sinusoid al jitter
Figure 21. Reveive tolerance eye mask
Cheetah T10 SAS Product Manual, Rev. A63
The leading and trailing edge slopes of figure 20 shall be preserved. As a result the amplitude value of Z1 is
less than that given in table 20 and Z1
and Z1OP shall be defined from those slopes by the following equa-
is the value for Z1 to be used for the tolerance masks; and
TOL
Z1OP, X1OP, and X2OP are the values in table 20 for Z1, X1, and X2.
The X1 points in the receive tolerance masks are greater than the X1 points in the receive masks, due to the
addition of sinusoidal jitter.
Figure 22 defines the sinusoidal jitter mask.
Peak-to-
peak
sinusoidal
jitter
(in UI)
1.5
1.0
Si nusoidal j i tter frequency
(log/log plot)
= 1.5 x 109 for 1.5 Gbps
F
NOM
F
= 3.0 x 109 for 3.0 Gbps
NOM
0.1
0
F
/ 25,000F
NOM
Frequency (in kHz)
Figure 22. Sinusoidal jitter mask
NOM
/ 1,667
64Cheetah T10 SAS Product Manual, Rev. A
9.5.2.2Transmitter signal characteristics
Table 19 specifies the signal requireme nts at the transmitter end of a TxRx connection as measured into the
zero-length test load. All specifications are based on differential measurements.
The OOB sequence is performed at signal voltage levels corresponding to the lowest supported transfer rate.
Table 19 specifies the signal characteristics.
Table 19: Tr ansmitter signal characteristics
Signal characteristic
b
Skew
Tx Off Voltage
Maximum rise/fall time
Minimum rise/fall time
Maximum transmitter output imbalance
OOB offset delta
OOB common mode delta
a All tests in this table shall be performed with zero-length test load shown in figure 24.
b The skew measurement shall be made at the midpoint of the transition with a repeating 0101b pattern on the physical
link. The same stable trigger, coherent to the data stream, shall be used for both the Tx+ and Tx- signals. Skew is
defined as the time difference between the means of the midpoint crossing times of the Tx+ signal and the Tx- signal.
c The transmitter off voltage is the maximum A.C. voltage measured at compliance points when the transmitter is
unpowered or transmitting D.C. idle (e.g., during idle time of an OOB signal).
d Rise/fall times are measured from 20 % to 80 % of the transition with a repeating 0101b pattern on the physical link.
e The maximum difference between the V+ and V- A.C. RMS transmitter amplitudes measured on a CJTPAT test
pattern (see 9.5.2.3.3) into the test load shown in figure 24, as a percentage of the average of the V+ and V- A.C.
RMS amplitudes.
f The maximum difference in the average differential voltage (D.C. offset) component between the burst times and the
idle times of an OOB signal.
g The maximum difference in the average of the common mode voltage between the burst times and the idle times of
Table 20 defines the compliance point requiremen ts of the signal at the receiver end of a TxRx connection as
measured into the test loads specified in figure 23 and figure 24.
Table 20: Receiver signal characteristics
Signal characteristicUnits1.5 Gbps3.0 Gbps
Jitter (see figure 20)
b
N/ASee table 21See table 21
2 x Z2mV(P-P)1,2001,600
2 x Z1mV(P-P)325275
a
X1
UI0.2750.275
X2UI0.500.50
d
Skew
ps8075
Max voltage (non-op)mV(P-P)2.0002.000
Minimum OOB ALIGN burst amplitude
Maximum noise during OOB idle time
Max near-end crosstalk
a The value for X1 shall be half the value given for total jitter in table 21. The test or analysis shall include the effects of
a single pole high-pass frequency-weighting function that progressively attenuates jitter at 20 dB/decade below a
frequency of ((bit rate) / 1,667).
b The value for X1 applies at a total jitter probability of 10
between the mask and actual signals is not a valid method for determining compliance with the jitter output
requirements.
c With a measurement bandwidth of 1.5 times the baud rate (i.e. 4.5 GHz for 3.0 Gbps).
d The skew measurement shall be made at the midpoint of the transition with a repeating 0101b pattern on the physical
link. The same stable trigger, coherent to the data stream, shall be used for both the Rx+ and Rx- signals. Skew is
defined as the time difference between the means of the midpoint crossing times of the Rx+ signal and the Rx- signal.
e Near-end crosstalk is the unwanted signal amplitude at receiver terminals DR, CR, and XR coupled from signals and
noise sources other than the desired signal. Refer to SFF-8410.
e
c
c
mV(P-P)240240
mV(P-P)120120
mV(P-P)100100
-12
. At this level of probability direct visual comparison
9.5.2.3.1Jitter
Table 21 defines the maximum allowable jitter .
Table 21: Maximum allowable jitter
1.5 Gbps m,
Deterministic jitter
0.350.550.350.55
a Units are in UI.
b The values for jitter in this section are measured at the average amplitude po i n t.
c Total jitter is the sum of deterministic jitter and random jitter. If the actual deterministic jitter is less than the maximum
specified, then the random jitter may increase as long as the total jitter does not exceed the specified maximum total
jitter.
d Total jitter is specified at a probability of 10
e The deterministic and total values in this table apply to jitter after application of a single pole high-pass frequency-
weighting function that progressively attenuates jitter at 20 dB/decade below a frequency of ((bit rate) / 1
f If total jitter received at a ny point is less than the maximum allowed, then the jitter distribution of the signals is allowed
to be asymmetric. The total jitter plus the magnitude of the asymmetry shall not exceed the allowed maximum total
jitter. The numerical difference between the average of the peaks with a BER < 10
individual events is the measure of the asymmetry. Jitter peak-to-peak measured < (maxi mum total jitter -
|Asymmetry|).
q
n
Total jitterc,d,e,fDeterministic jittereTotal jitterc,d,e,f
-12
.
3.0 Gbps m,
-12
n
667).
and the average of the
66Cheetah T10 SAS Product Manual, Rev. A
9.5.2.3.2Receiver jitter tolerance
Table 22 defines the amount of jitter the receiver shall tolerate .
Table 22: Receiver jitter tolerance
jitter
e,f,h
a
Total
jitter
h
Sinusoidal
b,d
jitter
-12
. Receivers shall tolerate sinusoidal jitter of
-12
. The additional 0.1 UI of sinusoidal jitter is
3.0 Gbps
Deterministic
1.5 Gbps
Sinusoidal
b,c
jitter
0.100.350.650.100.350.65
a Units are in UI.
b The jitter values given are normative for a combination of deterministic jitter, random jitter , and sinusoidal jitter that
receivers shall be able to tolerate without exceeding a BER of 10
progressively greater amplitude at lower frequencies, according to the mask in figure 22 with the same deterministic
jitter and random jitter levels as were used in the high frequency sweep.
c Sinusoidal swept frequency: 900 kHz to > 5 MHz.
d Sinusoidal swept frequency: 1.800 kHz to > 5 MHz.
e No value is given for random jitter. For compliance with this standard, the actual random jitter amplitude shall be the
value that brings total jitter to the stated value at a probability of 10
added to ensure the receiver has sufficient operating margin in the presence of external interference.
f Deterministic jitter: 900 kHz to 750 MHz.
g Deterministic jitter: 1.800 kHz to 1.500 MHz.
h The deterministic and total values in this table apply to jitter after application of a single pole high-pass frequency-
weighting function that progressively attenuates jitter at 20 dB/decade below a frequency of ((bit rate) / 1.667).
Deterministic
jitter
e,g,h
a
Total
h
jitter
9.5.2.3.3Compliant jitter test pattern (CJTPAT)
The CJTPAT within a compliant protocol frame is used for all jitter testing unless otherwise specified. See the
SAS Interface Manual for definition of the required pattern on the physical link and information regarding spe
cial considerations for scrambling and running disparity.
-
9.5.2.3.4Impedance specifications
Table 23 defines impedance requirements.
Table 23: Impedance requirements (Sheet 1 of 2)
RequirementUnits1.5 Gbps3.0 Gbps
Time domain reflectometer rise time 20 % to 80 %
a,b
ps10050
Media (PCB or cable)
Differential impedance
Differential impedance imbalance
Common mode impedance
ohm20 min/40 max20 min/40 max
Transmitter source termination
Differential impedance
Differential impedance imbalance
Common mode impedance
a All times indicated for time domain reflectometer measurements are recorded times. Recorded times are twi ce the
transit time of the time domain reflectometer signal.
b All measurements are made through mated connector pairs.
c The media impedance measurement identifies the impedance mismatches present in the media when terminated in
its characteristic impedance. This measurement excludes mated connectors at both ends of the media, when
present, but includes any intermediate connectors or splices. The mated connectors measurement applies only to the
mated connector pair at each end, as applicable.
d Where the media has an electrical length of > 4 ns the procedure detailed in SFF-8410, or an equivalent procedure,
shall be used to determine the impedance.
e The receiver termination impedance specification applies to all receivers in a TxRx connection and covers all time
points between the connector nearest the receiver, the receiver, and the transmission line terminator. This
measurement shall be made from that connector.
f At the time point corresponding to the connection of the receiver to the transmission line the input capacitance of the
receiver and its connection to the transmission line may cause the measured impedance to fall below the minimum
impedances specified in this table. The area of the impedance dip (amplitude as
duration in time) caused by this capacitance is the receiver termination time constant. The receiver time constant
shall not be greater than the values shown in this table. An approximate value for the receiver termination time
constant is given by the product of the amplitude of the dip (as
point. The amplitude is defined as being the difference in the reflection coefficient between the reflection coefficient at
the nominal impedance and the reflection coefficient at the minimum impedance point. The value of the receive r
excess input capacitance is given by the following equation:
ohm60 min/115 max 60 min/115 max
ohm55
ohm15 min/40 max15 min/40 max
ρ, the reflection coefficient, and
ρ) and its width (in ps) measured at the half amplitude
where (R0 || RR) is the parallel combination of the transmission line characteristic impedance and
termination resistance at the receiver.
g The difference in measured impedance to ground on the plus and minus terminals on the interconnect, transmitter or
receiver, with a differential test signal applied to those terminals.
9.5.2.4Electrical TxRx connections
TxRx connections may be divided into TxRx connection segments. In a single TxRx connection individual
TxRx connection segments may be formed from differing media and materials, including traces on printed wir
ing boards and optical fibers. This subclause applies only to TxRx connection segments that are formed from
electrically conductive media.
Each electrical TxRx connection segment shall comply with the impedance requirements of table 23 for the
media from which they are formed. An equalizer network, if present, shall be part of the TxRx connection.
TxRx connections that are composed entirely of electrically conducting media shall be applie d only to homoge nous ground applications (e.g., betw een device s within an enclosure or rack, or between enclosures interconnected by a common ground return or ground plane).
9.5.2.4.1Transmitter characteristics
The drive is D.C. coupled.
-
68Cheetah T10 SAS Product Manual, Rev. A
A combination of a zero-length test load and the transmitter compliance transfer function (TCTF) test load
6
0
10
20
methodology is used for the specification of transmitter characteristics. This methodology specifies the trans
mitter signal at the test points on the required test loads. The transmitter uses the same settings (e.g., preemphasis, voltage swing) with both the zero-length test load and the TCTF test load. The signal specifications
at IR are met under each of these loading conditions.
The TCTF is the mathematical statement of the transfer fu nction through which the transmitte r shall be capable
of producing acceptable signals as defined by a receive mask. The transmission magnitude response of the
TCTF in dB is given by the following equation for 1.5 Gbps:
6–
S
21
for 50 MHz < f < 1.5 GHz, and:
20–log10e()65,10
05,
f
××()20,10
10–
f××()33,10
20–
f2××()++()× dB×=
-
S
21
for 1.5 GHz < f < 5.0 GHz,
where:
a) f is the signal frequency in hertz.
The transmission magnitude response of the TCTF in dB is given by the following equation for 3.0 Gbps:
S
21
for 50 MHz < f < 3.0 GHz, and:
S
21
for 3.0 GHz < f < 5.0 GHz,
where f is the signal frequency in hertz.
The TCTF is used to specify the requirements on transmitter s that may or may not in corporate pre- emphasis or
other forms of compensation. A compliance interconnect is any physical interconnect with loss equal to or
greater than that of the TCTF at the above frequencies that also meets the ISI loss requirements shown in
ure 25 and figure 26.
Compliance with the TCTF test load requirement is verified by measuring the signal produced by the transmitter through a physical compliance interconnect attached to the transmitter.
Compliance with the zero-length test load requirement verified by measurement made across a load equivalent to the zero-length load shown in figure 24.
5 437,–dB=
20–log10e()65,10
10 884,–dB=
–
5,
f
××()20,10
–
f××()33,10
–
f2××()++()× dB×=
fig-
For both test load cases, the transmitter delivers the output voltages and timing listed in table 20 at the designated compliance points. The default mask is IR for intra-cabinet TxRx connectio ns. The eye masks are sho wn
in
9.5.2.1.
Figure 23 shows the compliance interconnect test load.
10 nF50 ohm
Tx +
10 nF
P robe
points
50 ohm
TCTF
Tx -
SAS internal connector
Figure 23. Compliance interconnect test load
Cheetah T10 SAS Product Manual, Rev. A69
Figure 24 shows the zero-length test load.
Tx +
Tx -
SAS internal connector
10 nF
10 nF
50 ohm
P robe
points
50 ohm
Figure 24. Zero-length test load
Figure 25 shows an ISI loss example at 3.0 Gbps.
(dB)
S
21
C ompliance interconnect magnitude response and
0
ISI loss
> 3.9 dB
ISI loss exam ple for 3.0 Gbps
10.9 dB
0.3
Sample compliance interconnect
3.01.5
Figure 25. ISI loss example at 3.0 Gbps
Figure 26 shows an ISI loss example at 1.5 Gbps.
S
(dB)
21
0
Compliance interconnect magnitude response and ISI
ISI loss
> 2.0 dB
-5.4 dB
0.15
loss exam ple for 1.5 Gbps
Sample c ompliance i nterconnec t
1.50.75
Frequency (GHz)
Frequency (GH z)
Figure 26. ISI loss example at 1.5 Gbps
70Cheetah T10 SAS Product Manual, Rev. A
9.5.2.5Receiver characteristics
The drive receiver is A.C. coupled. The receive network terminates the TxRx connection by a 1 00 ohm eq uiva lent impedance as specified in table 23.
The receiver operates within a BER of 10
-12
when a SAS signal with valid voltage and timing characteristics is
delivered to the compliance point from a 100 ohm source. The received SAS signal are considered valid if it
meets the voltage and timing limits specified in
table 20.
Additionally the receiver operates within the BER objective when the signal at a receiving phy has the additional sinusoidal jitter present that is specified in table 22 and the common mode signal VCM over frequency
range FCM as specified in table 18. The jitter tolerance is shown in Figure 22 for all Rx compliance points in a
TxRx connection. The figure given assumes that any extern al interference occu rs prior to the point at which the
test is applied. When testing the jitter tolerance capability of a receiver, the additional 0.1 UI of sinusoidal jitter
may be reduced by an amount proportional to the actual externally induced interference between the applica
tion point of the test and the input to the receiving phy. The additional jitter reduces the eye opening in both
voltage and time.
-
Cheetah T10 SAS Product Manual, Rev. A71
72Cheetah T10 SAS Product Manual, Rev. A
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Cheetah T10 SAS Product Manual, Rev. A73
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Brazil
Jabil Industrial Do Brasil—+55-11-4191-4761+55-11-4191-5084
LTDA
4
3
—+1-956-664-4725
SeagateRMA.br@jabil.com
Data Recovery Services
Call centerToll-freeDirect dialFAX
USA, Canada, 1-800-475-01435+1-905-474-21621-800-475-0158
and Mexico+1-905-474-2459
1
Hours of operation are 8:00 A.M. to 7:00 P.M., Monday through Friday (Central time).
2
Hours of operation are 8:00 A.M. to 8:00 P.M., Monday through Friday (Central time).
3
Hours of operation are 8:00 A.M. to 5:00 P.M., Monday through Friday (Central time).
4
Authorized Service Center
5
Hours of operation are 8:00 A.M. to 8:00 P.M., Monday through Friday, and 9:00 A.M. to 5:00 P.M., Saturday (Eastern time).
74Cheetah T10 SAS Product Manual, Rev. A
European support services
For presales and technical support in Europe, dial the Seagate Service Center toll-free number for your specific location. If your location is not listed here, dial our presales and technical support call center at +1-405324-4714 from 8:00
The presales and technical support call center is located in Oklahoma City, USA.
For European warranty service, dial the toll-free number for your specific location. If your location is not listed
here, dial our European CSO warranty center at +31-20-316-7222 from 8:30
time) Monday through Friday. The CSO warranty center is located in Amsterdam, The Netherlands.
A.M. to 1 1:45 A.M. an d 1:00 P.M. to 5:00 P.M. (Centr al Eu rope tim e) Monday thr ou gh Frid ay.
A.M. to 5:00 P.M. (Central Europe
Seagate Service Centers
Toll-free support numbers
Call centerPresales and Technical SupportWarranty Service
For presales and technical support in Africa and the Middle East, dial our presales and technical support call
center at +1-405-324-4714 from 8:00
A.M. to 11:45 A.M. and 1:00 P.M. to 5:00 P.M. (Central Europ e time) Mon -
day through Friday. The presales and technical support call center is located in Oklahoma City, USA.
For warranty service in Africa and the Middle East, dial our European CSO warranty center at +31-20-316-
7222 from 8:30
A.M. to 5:00 P.M. (Central Europe time) Monday through Friday, or send a FAX to +31-20-653-
3513. The CSO warranty center is located in Amsterdam, The Netherlands.
Asia/Pacific support services
For Asia/Pacific presales and technical support, dial the toll-free number for your specific location. The Asia/
Pacific toll-free numbers are available from 6:00
A.M. to 10:45 A.M. and 12:00 P.M. to 6:00 P.M. (Australian East-
ern time) Monday through Friday, except as noted. If your location is not listed here, direct dial one of our technical support locations.
Warranty service is available fr om 9:00 A.M. to 5:00 P.M., Monday through Friday. Warranty service for Australia
is available from 10:00
A.M. to 7:00 P.M., April through October, and from 11:00 A.M. to 8:00 P.M. November
through March (Australian Eastern time) Monday through Friday.
Seagate Service Centers
Call centerToll-freeDirect dialFAX
Australia1800-14-7201——
China (Mandarin)
Hong Kong800-90-0474——
Hong Kong (Cantonese)
2, 4
India
Indonesia001-803-1-003-2165——
3, 4
Japan
3, 4
Korea
Malaysia1-800-80-2335——
New Zealand0800-443988——
Singapore800-1101-150—+65-6488-7525
Taiwan (Mandarin)
Thailand001-800-11-0032165——
Hours of operation are 8:30 A.M. to 5:30 P.M., Monday through Friday (Australian Western time).
2
Hours of operation are 9:00 A.M. to 6:00 P.M., Monday through Saturday.
3
Hours of operation are 9:30 A.M. to 6:30 P.M., Monday through Friday.
4
Authorized Service Center
76Cheetah T10 SAS Product Manual, Rev. A
—+91-44-42015000+91-44-42015184
Index
Numerics
12 volt
pins 61
5 volt pins 61
A
abort task set function 45
AC coupling 61
AC power requirements 23
ACA active status 56
ACA active, faulted initiator status 56
acoustics 36
active LED Out signal 61
actuator
assembly design 7
adaptive caching 56
AFR 9
air cleanliness 35
air flow 42
illustrated 42
air inlet 42
altitude 33
ambient 32
ambient temperature 42
ANSI documents
SCSI 5
Serial Attached SCSI 5
asynchronous event notification 56
audible noise 3
auto write and read reallocation
programmable 8
automatic contingent allegiance 56
average idle current 23, 24
average rotational latency 11
B
Background Media Scan 39
backpanel 60
BMS 39
buffer
data 8
space 13
busy status 56
C
cache operation 13
cache segments 13
caching write data 14
Canadian Department of Communications 3
capacity
unformatted 11
check condition status 56
chemical pollutants 35
class B limit 3
clear ACA function 45
clear task set function 45
commands supported 47
condensation 33
condition met/good status 56
connector
sequencing 25
power distribution 3
power-on operating hours 16
power-up hours 16
prefetch/multi-segmented cache control 13
preventive maintenance 15
Q
queue tagging 56
R
radio interference regulations 3
RCD bit 13
read error rates 15, 37
read/write data heads 11
receivers 61
recommended mounting 34
Recoverable Errors 15
recovered media data 15
reference
documents 5
relative humidity 33
reliability 9
specifications 15
reliability and service 16
repair and return information 21
reporting actual retry count 56
reservation conflict status 56
resonance 33
return information 21
rotation speed 11
S
safety 3
SAS
interface 60
physical interface 57
task management functions 45
SAS documents 5
SAS Interface Manual 3, 5
SCSI interface
commands supported 47
seek error
defined 16
rate 15
seek performance characteristics 11
seek time
average typical 11
full stroke typical 11
single track typical 11
segmented caching 56
Self-Monitoring Analysis and Reporting Technology