For those new to SSDs, it is important to recognize that the most visible upgrade one will see in a computer is that achieved through migrating a hard drive to an SSD. It is more visible than increasing RAM or even preferring a higher CPU. If you have been relying on a hard drive previous to trying a SSD for the first time, be ready for it as you will be amazed. I remember being quoted as describing this visible performance increase as, “the computer knowing what you are going to do before you do”, a few years back when an SSD purchase was simply not affordable to the typical consumer.
With respect to this comparison, we are pitting the best mSATA SSD that we have ever tested against one of the worst. Lets first take a look at the compressible performance of this SSD.
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.
To the uneducated consumer, this result looks great and definitely hits the SATA 3 range. Manufacturers use this type of testing to determine their specifications because they understand that sales are achieved where the consumer can relate to higher performance. What the consumer is not aware of is that these high transfer speeds of 492MB/s read and 314MB/s write are reached through high sequential disk access, this being a level of transfer that will only be used in less than 1% of their activities.
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 can’t 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.
Using Crystal DiskMark, we have tested both the U100 (left) and SMART SSD (right) and we can obviously see a significant difference. Not concentrating on the Sequential or even 512k transfer levels, take a look specifically at the low 4k random write results. The’low 4k’ transfer is very important as it is seconded only to disk access speed where a visible performance upgrade is observed. In short, the higher the low 4k random write transfer speed, the more likely it wil be that we observe a performance increase.
In these two results, we used highly incompressible data as the data sample, this data being simlar to that of music, movies or photographs. At first, it may almost appear that the Sandisk betters the MyDigitalSSD SMART simply because of the Sequential write scores but remember, low 4k random writes are the key to visible performance increase.