# Get a decent idea about the steady state performance of an SSD. # # First we sequentially write the drive. Then we completely # overwrite the device again, this time randomly at 4K. The former gives # us a good idea of the ideal write performance, you should see flat graph # of steady write performance. The latter we would expect to start out at # approximately the same rate as the sequential fill, but at some point # hit a write cliff and hit steady state. The latency numbers of the steady # state also provide a good idea of what kind of latencies to expect when # the device is pushed to steady state instead of peak benchmark-like # numbers that are usually reported. # # Note that this is a DESTRUCTIVE test. It operates on the device itself. # It's not destructive in the sense that it will ruin the device, but # whatever data you have on there will be gone. # [global] ioengine=libaio direct=1 group_reporting filename=/dev/fioa [sequential-fill] description=Sequential fill phase rw=write iodepth=16 bs=1M [random-write-steady] stonewall description=Random write steady state phase rw=randwrite bs=4K iodepth=32 numjobs=4 write_bw_log=fioa-steady-state