HP A6826A User guide

A6826A – PCI-X Dual port 2Gb/s Fibre Channel Adapter

Performance Paper for PCI platforms

Table of contents

Introduction...............................................................................................................................................2

Executive summary.....................................................................................................................................2

Test results ................................................................................................................................................3

IOPs .....................................................................................................................................................3

Service demand.....................................................................................................................................3

Throughput............................................................................................................................................4

Scalability .............................................................................................................................................5

System configuration guidelines...................................................................................................................7

Test details................................................................................................................................................8

Products used in testing...........................................................................................................................8

Test configuration...................................................................................................................................9

Additional Information................................................................................................................................9

Introduction

This paper provides basic I/O performance and scalability information for the A6826A dual-channel 2Gb Fibre Channel adapter on HP’s PCI platforms. A series of tests were conducted to evaluate the adapter’s performance on HP servers, namely rp5450, rp7400, rp8400 and Superdome. The tests measured the IOPS and throughput of single and multiple adapters.

This paper addresses the performance capabilities of A6826A when used with the above mentioned HP platforms. The paper also discusses the system setup considerations to obtain the maximum possible performance from A6826A on these platforms.

This paper focuses on the following topics:

• Test results: Single and multiple adapters performance data, which include the IOPS and throughput

for single and dual ports, will be discussed.

• Scalability: Multiple adapter scalability tests on systems namely Superdome, rp8400, rp7400 and

rp5450 will be discussed.

• System configuration guidelines: Superdome, rp8400, rp7400 and rp5450 system configurations

and recommendations will be discussed.

• Test details: HP’s products used, test setup, benchmark tool used and system configuration in the test

setup will be discussed.

Executive summary

A6826A on HP mid range and high end platforms offers an excellent SAN solution. A6826A provides read throughput of 195MB/s, and write throughput of 188MB/s on a single port. With dual ports a read throughput of 390MB/s, and write throughput of 368MB/s are achieved.

A6826A performance summary

Operation

iops 35530 21300 20300 70100 42700 31300

throughput

(MB/s)

NOTE:

*bd: Bidirectional Operation. **The full duplex throughput is limited by 66MHz PCI bandwidth (528 MB/s). The above performance data is obtained on A6826A seated in a 66MHz PCI slot of a single cell single CPU (750MHz) rp8400.

achieved 195 188 351 390 368 412**

% of 2Gb/s FC

theoretical max

read write bd* read write bd

single port two ports

97.5 94 87.7 97.5 92 51.1

On rp8400 and Superdome A6826A provides outstanding performance with linear scaling up to 4 cards, when all the eight ports are being used at 2Gb/s bandwidth. Additional cards may be added to provide greater connectivity. The card delivers excellent performance in limited configurations on rp7400 and rp5450.

Test results

Diskbench (db) utility is used to generate the read and write test traffic. Various block size tests were executed for read and write on single and dual ports. The IOPS metric are obtained with 1 KB block size transfers. The throughput metric is obtained with 128 KB block size transfers. The throughput metric is useful in modeling large sequential transfers such as remote backup etc. The IOPS metric is useful in modeling small transactional traffic.

IOPs

Chart 1a: IOPS (in thousands) Chart 1b: % CPU Utilization

IOPs

Read

Write

80000

70000

60000

50000

40000

30000

20000

10000

35530 70100

21300 42700

Numbe r of P orts

% CPU Uitlization

Read

Write

100

40.02 92.85

25.77 54.29

Number o f Po rts

The chart, chart 1a, shows the number of IO operations per second for read and write operations on single and dual ports of A6826A. The X-axis is the number of ports and the Y-axis the number of IO operations per second.

The chart 1a shows linear scaling of IOPS for single and dual ports. The number of read IO operations per second for single port is 35530 and for dual ports are 70100. The number of write operations per second for single port is 21300 and for dual port are 42700. The IOPS metric for A6826A is limited by the processor used on A6826A.

The chart 1b shows the CPU utilization for the IO operation tests.

The chart 1b shows the % CPU utilization for IO operation tests. The X-axis is number of the Fibre Channel ports. The Y-axis is the % CPU utilization. Only one 1 CPU is configured in these tests, hence this is a single CPU utilization.

Service demand

A6826A offers a great service demand for small size IO operations. To illustrate service demand of A6826A small size operations tests were conducted using db. Read and write operations of IO sizes of 4KB and 8KB were performed on a single cell single CPU rp8400 and the results were recorded.

The following table shows single and dual port throughput and CPU utilization for Sequential Read and Sequential Writes with 4KB and 8KB IO sizes.

Number

of Ports

Thru

CPU2

Single 130 37% Dual 275 74%

NOTE:

Throughput in MB/s

Single CPU utilization

Service Demand =

Data gathered on single cell single CPU rp8400

Sequential Read Sequential Write

4KB 8KB 4KB 8KB

SD3

Thru CPU

2.93

2.75

((%CPU utilization/100)/Throughput in KB/sec)

190 25% 379 65%

1.34

1.75

Thru CPU

83 25% 164 53%

3.08

3.30

Thru CPU

127 20% 248 58%

1.61

2.39

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