We used CrystalDiskMark 8‘s custom settings to test the 4K random read performance of the drive through a range of queue depths. The setup for the tests is listed below.
Transfer Request Size: 4KB, Outstanding I/O: 1-32.
WD rate the 4K random read performance of the 1TB Black SN770 as up to 740,000 IOPS. Using our 4-threaded 4K random testing, the best we saw was 448,613 IOPS (QD32).
4K Random Read v QD Performance compared.
The WD Black SN770 performs well at both ends of our 4K random read tests. At QD1 it sits in third place (69,498 IOPS) and at QD32 it tops the chart (448,613 IOPS). However, the final figure of 448,613 IOPS is a long way short of the official maximum of 740,000 IOPS.