ATTO Disk Benchmark is perhaps one of the oldest benchmarks going and is definitely the main staple for manufacturer performance specifications. ATTO uses RAW or compressible data and, for our benchmarks, we use a set length of 256mb and test both the read and write performance of various transfer sizes ranging from 0.5 to 8192kb. Manufacturers prefer this method of testing as it deals with raw (compressible) data rather than random (includes incompressible data) which, although more realistic, results in lower performance results.
Crystal Disk Benchmark is used to measure read and write performance through sampling of raw (0/1 Fill/compressible) or random data which is, for the most part, incompressible. Many new SandForce Driven SSD owners who cant wait to test the performance of their SSD often grab this program and run a quick test, not realizing that they are testing with incompressible data rather than compressible data used in testing by manufacturers. We have provided compressible (oFill) results on the left with incompressible (random data) results on the right.
For those new to SSDs, the result on right is typical when testing incompressible data and displaying it next to the results of compressible data (left), incompressible data consisting mainly of music files, video and photographs. These results are only indicative of transfer speeds and wouldn’t affect media playback whatsoever. Conversely, excellent low 4k write transfer speeds of 98MB/s give us a heads up that this SSD will be showing some nice numbers as we further our testing.
Up until recently, ATTO was the only benchmark created specifically for SSD testing and it uses incompressible data. AS SSD, for the most part, gives us the worst case scenario in SSD transfer speeds because of its use of incompressible data and many enthusiasts like to AS SSD for their needs. Transfer speeds are displayed on the left with IOPS results on the right.
Our AS SSD results confirm that of which we saw in Crystal DiskMark while testing in incompressible data and go a step further by showing some great disk access speeds. The IOPS results are a bit lower than the specifications list but this is typical of AS SSD.