Performance testing MD1000 SATA vs SAS

I have 2 MD1000 Powervaults, one with SAS 15K rpm drives, the other with 7.2K rpm SATA Drives, both connected via PERC5/e cards to CentOS 4.6 servers.

 

I have been trying to determine just how much faster the SAS drives are than the SATA, or it they are at all by using sys-bench.  I seem to be getting some interesting metrics for the random read/write tests, the SAS drives seem to be ~3-4 times faster, which I am very surprised at, below are my test commands.

 

 /usr/local/sysbench/bin/sysbench --num-threads=100 --test=fileio --file-total-size=404G --file-test-mode=rndrw run

sysbench v0.4.8:  multi-threaded system evaluation benchmark

 

Running the test with following options:

Number of threads: 100

 

Extra file open flags: 0

128 files, 3.1562Gb each

404Gb total file size

Block size 16Kb

Number of random requests for random IO: 10000

Read/Write ratio for combined random IO test: 1.50

Periodic FSYNC enabled, calling fsync() each 100 requests.

Calling fsync() at the end of test, Enabled.

Using synchronous I/O mode

Doing random r/w test

Threads started!

Done.

 

Operations performed:  5983 Read, 4020 Write, 10630 Other = 20633 Total

Read 93.484Mb  Written 62.812Mb  Total transferred 156.3Mb  (19.882Mb/sec)

 1272.47 Requests/sec executed

 

Test execution summary:

    total time:                          7.8611s

    total number of events:              10003

    total time taken by event execution: 147.6844

    per-request statistics:

         min:                            0.0000s

         avg:                            0.0148s

         max:                            1.7304s

         approx.  95 percentile:         0.0687s

 

Threads fairness:

    events (avg/stddev):           100.0300/38.37

    execution time (avg/stddev):   1.4768/0.80

 

THE SATA DRIVES:

 

 /usr/local/sysbench/bin/sysbench --num-threads=100 --test=fileio --file-total-size=404G --file-test-mode=rndrw run

sysbench v0.4.8:  multi-threaded system evaluation benchmark

 

Running the test with following options:

Number of threads: 100

 

Extra file open flags: 0

128 files, 3.1562Gb each

404Gb total file size

Block size 16Kb

Number of random requests for random IO: 10000

Read/Write ratio for combined random IO test: 1.50

Periodic FSYNC enabled, calling fsync() each 100 requests.

Calling fsync() at the end of test, Enabled.

Using synchronous I/O mode

Doing random r/w test

Threads started!

Done.

 

Operations performed:  5994 Read, 4018 Write, 10392 Other = 20404 Total

Read 93.656Mb  Written 62.781Mb  Total transferred 156.44Mb  (7.4698Mb/sec)

  478.07 Requests/sec executed

 

Test execution summary:

    total time:                          20.9425s

    total number of events:              10012

    total time taken by event execution: 435.0173

    per-request statistics:

         min:                            0.0000s

         avg:                            0.0434s

         max:                            12.1518s

         approx.  95 percentile:         0.0114s

 

Threads fairness:

    events (avg/stddev):           100.1200/49.42

    execution time (avg/stddev):   4.3502/4.81

 

Does anyone have any other suggestions for performance testing the Powervaults, I'm using for for MySQL5 DBs.