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.
Initial ATTO results of 557MB/s read and 532MB/s write are excellent and typical of most ‘LSI SandForce Driven’ SSDs.
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.
If you are looking at Crystal DiskMark benchmarks and observe that the write performance at high sequential and 512k write disk access is lower when testing random, or incompressible data, than that of highly compressible, or 0Fill, data as shown on the left, this is normal for SSDs using the LSI SandForce FSP and an easy way to identify such. A closer look at these two results shows the 4k write performance of 102MB/s when testing in incompressible data and this is something we always like to see. As much as we might hope, having low 4k write performance this high is still very rare and a great indicator of the caliber of the drive being tested.
Up until recently, AS SSD 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.
These AS SSD results are typical of most SSDs and the Total Score is actually a bit low. This is rather strange as our AS SSD Copy Benchmark resulted in the fastest transfer speeds we have seen from any SSD to date. Obtaining consistent SATA 3 results in all three tests is a rarity. Having two performance benchmarks return over 400MB/s with all three in the SATA 3 realm is pretty much unheard of.