4KB RANDOM READ/WRITE
In order to properly test random 4KB performance, we first secure erase to get it in a clean state. Next, the drive is filled by sequentially writing to the RAW NAND capacity twice. We then precondition the drive with 4KB random writes at QD256 until the drive is in a steady state. Finally, we cycle through QD1-256 for 5 minutes each for writes and then reads. All this is scripted to run with no breaks in between. The last hour of preconditioning, the average IOPS, and average latency for each QD is graphed below.
Taking a look at our preconditioning data we can see that the average 4K write IOPS are a bit under spec with the 960GB model averaging 9.5 to 10K IOPs and the 800GB model averaging 25K IOPS. The above two graphs are also a very good representation of how you can improve your storage performance by simply over provisioning. Not only do the IOPS increase, performance consistency improves dramatically.
The Kingston DC400 seems to max out at around 78-80K IOPS for read with latency at just over 0.40ms at QD 32. This is under the rating of 99K. At QD1, however, there is a large gap between the 960GB and 800GB models with the 800GB model delivering double the performance and edging out up until QD16.
During 4K writes, the DC400 is the lowest performing drive at 960GB averaging10K IOPS. Once it was over-provisioned to 800GB, however, it delivers performance that is a bit better than the Micron M510DC, but just under the 5100 ECO at 25K IOPS.