Test Setup

Synthetic Testing

• Tests are run with a 20-second-long warm-up time (result recording starts at second 21).
• Between each test, the drive is left idle for 60 seconds to allow it to flush and reorganize its internal data.
• All write requests contain random, incompressible data.
• Disk cache is flushed between all tests.
• M.2 drives are tested with a fan blowing on them; that is, except for the results investigating uncooled behavior on the thermal testing page.

Real-life Testing

• After initial configuration and installation, a disk image is created; it is used to test every drive.
• Automated updates are disabled for the OS and all programs. This ensures that—for every review—each drive uses the same settings without any interference from previous testing.
• Our disk image consumes around 450 GB—partitions are resized to fill all available space on the drive. For 256 GB-class drives, the work load is split into two separate runs, game load time and all other tests.
• All drives are filled with random data to 80% of their capacity.
• Partitions are properly aligned.
• Disk cache is flushed between all tests.
• In order to minimize random variation, each real-life performance test is run twelve times with reboots between tests to minimize the impact of disk cache. The top and bottom outliers are removed and the ten remaining runs get averaged for the final score.
• All application benchmarks run the actual application and do not replay any disk traces.