a6825a / a6847a
pci gigabit ethernet
performance paper
using hp server rp7410
September 2002
U.S.A.
© 2002 Hewlett-Packard Company
the design
makes
the difference
Table of Contents
introduction ............................................................................................................................................. 1
summary................................................................................................................................................. 1
test details ............................................................................................................................................... 2
products used in testing........................................................................................................................ 2
test configuration ................................................................................................................................. 3
gigabit ethernet performance data ........................................................................................................... 4
throughput........................................................................................................................................... 5
average throughput per card................................................................................................................ 6
cpu utilization ...................................................................................................................................... 7
performance highlights ............................................................................................................................ 8
additional information ............................................................................................................................. 8
taking the next step ................................................................................................................................. 8
ii
Gigabit Ethernet Performance in rp7410 Servers
introduction
HP leads the industry in PCI Gigabit Ethernet (GbE) performance, reliability, and supportability. With
the introduction of the second generation PCI Gigabit Ethernet Adapters, HP extends its leadership
position.
HP’s new 1000Base-SX NIC solution (using multi-mode fiber cable and supporting distances of up to
550m) and 1000Base-T NIC solution (using CAT5 UTP cable and supporting distances of up to 100m)
both offer the same level of performance with the only difference being cost and distance.
This paper provides basic I/O performance information for the A6825A 1000Base-T and A6847A
1000Base-SX Gigabit Ethernet LAN Adapters when installed in the hp server rp7410. This paper is not
an exhaustive source for HP LAN adapter performance information. It provides a guideline for expected
performance from the A6825A and A6847A Gigabit Ethernet LAN Adapters.
Both the A6825A and A6847A Gigabit Ethernet adapters are designed to maximize server CPU
efficiency with advanced features such as protocol offloading through on-board TCP, UDP, and IP
checksum calculations and optional jumbo frame support (9000 byte maximum transfer unit, MTU) for
improved efficiency and performance with bulk data transfer.
The hp server rp7410 is a highly dependable, adaptable, and efficient midrange server for the data center.
The rp7410 brings added efficiency and economy of operation to the midrange server market.
This paper addresses the performance capabilities of the A6825A 1000Base-T and A6847A 1000Base-SX
Adapters when used in the hp server rp7410.
summary
The hp server rp7410 is an excellent midrange server, and with the HP Gigabit Ethernet NICs provides a
winning combination of capabilities.
The HP Gigabit Ethernet adapters together with the 8-way rp7410 provide outstanding networking
performance, with linear scaling of Transmit data and Receive data for up to 4 cards. Additional cards
may also be added to provide greater connectivity.
Page 1
test details
products used in testing
The following products were used for the performance measurement tests:
products used with netperf for the performance measurement test
Server
Tested
Clients
generating
the test
load
Benchmark
software
rp7410
• Eight, 750 MHz CPUs
• 16 GB RAM
• Operating System - HPUX 11i version
B.11.11.0203
A6847A PCI 1000Base-SX Adapter
• Gigabit Ethernet 1000 Base-SX LAN
• PCI-4X (64-bit, 66 MHz)
• LAN Driver version – Gigether-01
B.11.11.04
Sixteen j6000 workstations
• Two, 552 MHz CPUs each
• Operating System - HPUX 11i version
B.11.11.0112.6
Odd numbered j6000’s:
• One A6847A PCI 1000Base-SX Adapter
• LAN Driver version – GigEther-01
B.11.11.04
Even numbered j6000’s:
• One A4926A PCI 1000Base-SX Adapter
• LAN Driver version – GigEther-00
B.11.11.14
Netperf is the benchmark software suite that
generated LAN traffic for these performance
tests. For more information about netperf or to
get a free copy of netperf, go to
http://www.netperf.org
Page 2
Gigabit Ethernet Performance in rp7410 Servers
test configuration
The test configuration consists of an 8-way (750 MHz) rp7410 with 16 Gigabytes of system memory and
eight A6847A Gigabit Ethernet cards. The cards were connected to one of two HP 9304M Procurve
Routing Switches. The tests were repeated with different configurations of cards, and the results in all
cases were very similar.
The test load was generated by 16, 2-way j6000’s, each containing a single 1000Base-SX Gigabit
Ethernet Adapter. Each NIC in the rp7410 was connected to two j6000’s through a switch.
NOTES:
• The networking performance of the HP PCI 1000Base-SX NICs and PCI 1000Base-T NICs is
identical.
• The observed performance results are consistent across all I/O slots of the system.
Page 3
gigabit ethernet performance data
The performance of the Gigabit Ethernet adapters is measured with the following traffic types:
• Transmit (TX) using netperf with socket size of 128K bytes and message size of 32K bytes
• Receive (RX) using netperf with socket size of 128K bytes and message size of 32K bytes
• Bi-directional (BD) running the TX and RX tests concurrently
NOTE:
• The A6749-60001 core LAN/SCSI card in the rp7410 had only minimal site LAN traffic during
performance testing.
Page 4
throughput
4,500
4,000
3,500
3,000
2,500
2,000
1,500
1,000
10^6 bits per second
500
xmit
recv
bd
bd_xmit
bd_recv
Gigabit Ethernet Performance in rp7410 Servers
Gigabit Ethe r ne t Throughput on 8-Way rp7410
124
947.97 1,895.99 3,792.06
948.13 1,853.09 3,325.21
1,643.32 2,475.09 3,906.36
821.11 1,164.27 1,466.88
822.21 1,310.81 2,439.48
Nu m be r o f Car ds
The above chart shows the throughput performance of 1, 2, and 4 Gigabit Ethernet cards in an 8-way
rp7410. Throughput numbers are shown in 10^6 bits per second, or Mbps.
As the chart shows, one NIC transmits well over 947 Mbps of user data across the Gigabit Ethernet link.
Two NICs scale at 2x the performance of a single NIC to transmit 1895.99 Mbps. Four NICs scale at 4x
the performance of a single NIC, transmitting a total of more than 3792 Mbps of user data.
On the receive side, one NIC receives up to 948.13 Mbps of user data. Two NICs scale to approximately
2x the performance of a single NIC, receiving 1853.09 Mbps. Four NICs scale at approximately 4x the
performance of a single NIC, receiving up to 3325.21 Mbps.
The chart demonstrates outstanding performance, with linear scaling on transmit and receive for up to
four cards. Thus, the rp7410 supports up to four Gigabit Ethernet adapters at full unidirectional link rate.
Additional NICs can be added to provide greater connectivity, up to a total of 15 Gigabit Ethernet cards
for the system. For example, two more NICs add an additional 500 Mbps of bi-directional throughput,
yielding an aggregate bandwidth across the six NICs of 4413.41 Mbps of bi-directional data.
Page 5
average throughput per card
Gigabit Ethe r ne t Per Card Ave rage Thr oughput on 8-Way rp7410
1,800
1,600
1,400
1,200
1,000
800
600
10^6 bits per second
400
200
-
xmit
recv
bd
124
947.97 947.99 948.02
948.13 926.54 831.30
1,643.32 1,237.54 976.59
Nu m be r o f Car ds
As demonstrated in the chart above, the average throughput per card for transmit data is the same for two
cards and four cards as it is for a single card. The average throughput per card for receive data on two
and four cards compared to one card is exceptional as well.
The decline in average bi-directional throughput as the number of cards increases results from the rp7410
nearing the limit of its CPU capacity. This is discussed more fully on the following page.
Page 6
cpu utilization
100%
90%
80%
70%
60%
50%
40%
30%
Percent of CPUs Used
20%
10%
0%
xmit
recv
bd
Gigabit Ethernet Performance in rp7410 Servers
CPU Utilizatio n on 8-Way r p7410 for Gigabit Ethe r net
124
12.82% 26.90% 63.96%
28.17% 45.13% 91.16%
38.91% 68.76% 99.87%
Num be r o f Car ds
This chart shows the total amount of CPU utilization for 1, 2, and 4 Gigabit Ethernet cards in an 8-way
rp7410. With two NICs running at link rate with receive only traffic, the rp7410 still had approximately
55% of its CPU cycles available for other applications. When supporting two NICs with transmit only
traffic running at link rate, the rp7410 had over 73% of its CPU capacity available for other applications.
A total of four Gigabit Ethernet NICs can be operated at full link rate carrying unidirectional data without
driving the CPU utilization to the limits of its capacity.
With two NICs running at link rate and carrying bi-directional traffic, the rp7410 had over 31% of its
CPU cycles available for other applications. As illustrated in the above chart, when four NICs are
carrying bi-directional traffic the CPU utilization is very close to 100%. This indicates that the rp7410 is
reaching the limit of its CPU capacity. Bi-directional traffic consumes more of the system’s resources
than either transmit-only or receive-only traffic. Therefore, as the total volume of bi-directional traffic
increases, the demand on system resources increases faster than it does for unidirectional traffic.
This increasing load on the CPUs causes the limiting of bi-directional throughput as the number of cards
increases, as shown on the previous chart.
Page 7
performance highlights
• The rp7410 provides incredible network performance, supporting up to four Gigabit Ethernet NICs
running at link rate simultaneously with unidirectional traffic.
• The rp7410 scales linearly through four NICs with unidirectional traffic for industry-leading Gigabit
Ethernet performance.
• Additional Gigabit Ethernet NICs can be added for greater connectivity, up to a total of 15 NICs for
the system.
additional information
This paper is the latest in a series of white papers detailing the performance of HP’s link and server
products. For a complete list of white papers on HP’s Gigabit Ethernet solutions, go to
http://docs.hp.com/netcomm/index.html
Ethernet)” and look under “White Papers.”
, scroll down to “1000Base-T and 1000Base-SX (Gigabit
For more information about HP or other HP products go to http://www.hp.com/
For more information about HP’s full line of rack-optimized Unix servers, go to
http://www.hp.com/products1/servers/rackoptimized/index.html
For more information about HP’s super-scalable superdome server, go to
http://www.hp.com/products1/servers/scalableservers/index.html
For more information about the hp server rp7410 go to
http://www.hp.com/products1/servers/architecture/pa_risc/
and click on ‘rp7410’ to see the product brief.
The product brief provides an overview of the rp7410 and access to additional information such as the
rp7410 technical white paper. In the product information area of the product brief click on information
library to find a list of available documents.
For more information about the A6825A and A6847A Gigabit Ethernet Adapters, view the Gigabit
Ethernet family product brief at
http://www.hp.com/products1/unixserverconnectivity/adapters/ethernet/infolibrary/gigapbww_801.pdf
taking the next step
With performance that scales superbly through four Gigabit Ethernet NICs, the HP server rp7410 with the
A6825A / A6847A Gigabit Ethernet Adapters is a winning combination.
Contact your local hp Sales Representative for a current list of tested products and a detailed analysis of
specific requirements and needs.
Page 8
Gigabit Ethernet Performance in rp7410 Servers
Legal Notices
The information in this document is subject to change without notice.
Hewlett-Packard makes no warranty of any kind with regard to this white paper, including but not limited to the implied warranties of
merchantability and fitness for a particular purpose. Hewlett-Packard shall not be held liable for errors contained herein or direct,
indirect, special, incidental or consequential damages in connection with the furnishing, performance, or use of this material.
©Copyright 2002 Hewlett-Packard Company, all rights reserved.
HP-UX® is a registered trademark of the Hewlett-Packard Corporation. All other trademarks and registered trademarks are the property
of the respective corporations.
Reproduction, adaptation, or translation of this document without prior written permission is prohibited, except as allowed under the
copyright laws.
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