A6826A - PCI-X Dual port 2Gb/s Fibre Channel Adapter Performance Paper for PCI Platforms

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
0
10000
20000
30000
40000
50000
60000
70000
80000
Number of Ports
IOPs
Read
35530 70100
Write
21300 42700
12
0
10
20
30
40
50
60
70
80
90
100
Number of Ports
% CPU Uitlization
Read
40.02 92.85
Write
25.77 54.29
12
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.
Sequential Read Sequential Write
4KB 8KB 4KB 8KB
Number
of Ports
Thru
1
CPU
2
SD
3
Thru CPU SD Thru CPU SD Thru CPU SD
Single 130 37% 2.93 190 25% 1.34 83 25% 3.08 127 20% 1.61
Dual 275 74% 2.75 379 65% 1.75 164 53% 3.30 248 58% 2.39
NOTE:
1
Throughput in MB/s
2
Single CPU utilization
3
Service Demand =
((%CPU utilization/100)/Throughput in KB/sec)
Data gathered on single cell single CPU rp8400
3