Iometer: 4kB random read/write
We used Iometer to measure the random read speed using 4k data blocks at queue depths of 1 through 32.
Despite the fact that the Sandisk and WD are identical in terms of hardware, there is still the possibility of different tuning when it comes to the firmware. With QD1 the read performance of the WD is slightly better, but with QD32 the performance is practically identical.
When writing the WD seems to be faster with a low queue-depth, but this difference is negligible with higher queue-depths.