We used CrystalDiskMark 8 to test the random performance of the drive at lower queue depths (QD1 – QD8 where most of the everyday workloads occur) using 1 to 4 threads.
At QD1 the performance of the 1TB WD Black SN770 ranges from a low point of 20,422 IOPS (83MB/s) using a single thread up to 69,498 IOPS (284MB/s) using four threads. The performance increases steadily as the queue depth deepens for each thread count finishing at QD8 with figures ranging from 111,631 (457.24MB/s) for a single thread up to 280,276 IOPS (1,148MB/s) for four threads.
The WD Black SN770's write performance climbs smoothly throughout the tested queue depths and threads with a peak performance figure of 347,535 IOPS (1,407MB/s) at QD8 using four threads.