After some grueling IO testing on 7200rpm disks, I got my hands on some shiny new Samsung 840 SSDs and wanted to share the performance results in similar fashion.
Dell r630, E5-2630 v3 @ 2.40GHz (16 cores), 256GB RAM, Samsung 840 EV SSD 960GB.
Testing was sysbench, fileio-rndrw, async+direct io, 16 threads, 5.5TB RAID-6 using XFS mounted with noatime,inode64 and using the deadline scheduler.
|Write Policy||Read Policy||xfs options||Transfer/s||Requests/s||Avg/Request||95%/Request|
|WB||ADRA||sunit=16, swidth=576 blks||357.31Mb/sec||22868.08||0.17ms||0.70ms|
|WT||ADRA||sunit=16, swidth=576 blks||459.27Mb/sec||29393.37||0.14ms||0.53ms|
|WT||NORA||sunit=16, swidth=576 blks||448.07Mb/sec||28676.79||0.14ms||0.50ms|
|WT||ADRA||sunit=16, swidth=384 blks||450.69Mb/sec||28843.85||0.16ms||0.51ms|
WT = Write Through, WB = Write Back, ADRA = Adaptive Read Ahead; NORA = No Read Ahead
It’s a no brainer that SSDs are faster. For our testing, they were 7x faster than the previous 7200rpm tests and 4x faster than 15k platter in RAID-10 (15k results not published).
Edit: Clarified policy information and the speed differences from 7200/15k. Thanks Daniël van Eeden.