The majority of our test procedure consists of performance benchmarks. The HD Tune bechnmark shows, among other things, the average transfer rate and the average access time of the drives. We use the Atto benchmark to determine how quickly drives can read and write small (4 kB) and larger (1 MB) data blocks; four at a time. The Atto benchmark measures the average throughput rate when processing data of different block sizes. We take a closer look at the results for blocks of 4 kB, 64 kB and 1 MB. The results of the 1 MB test are primarily influenced by the maximum throughput rate of the hard drives, whereas the 4 kB test is influenced more by the average access time. The results of the 4 kB test are mainly of interest when you are planning on using the drive as a primary disk for your OS and programs; the results of the 1 MB test are the ones to look at for those who will be using the drive for data storage.
The PCMark 7 and 8 tests represent a situation where the drive would be used as primary disk, or rather, for starting and using programs. Both benchmarks are based on the hard drive activity patterns of real software. PCMark 7 uses programs from the Windows 7 era and PCMark 8 uses software from the Windows 8 era. These tests use so-called traces, recordings of drive usage when performing certain tasks.
Furthermore we measured the noise levels of the drives in a soundproof box at a distance of 10 cm; both when the drives were idle as well as during a random workload. Note that the numbers should be interpreted as follows: everything under the 30 dB(A) threshold is essentially inaudible at a rnomal distance. Everything under 40 dB(A) is as quiet as a whisper at a normal distance. Drives that exceed the 40 dB(A) threshold are clearly audible.
Finally, we also measured the power consumption of the drives, both when idle as well as when under load.