Disk Response Time
For 10 minutes IOMeter is sending a stream of requests to read and write 512-byte data blocks with a request queue of 1. The total of requests processed by each SSD is much larger than its cache, so we get a sustained response time that doesn’t depend on the SSD’s buffer size.
The Indilinx-based models all have the same read response time. The latest firmware has improved this parameter to 0.1 milliseconds. The Vertex 2 differs by a mere 0.03 milliseconds, but this small difference may translate into a considerable amount of operations per second.
As for writing, it is easy to see that large-capacity SSDs have a better response time. The models of different series are not similar, though. The Vertex Turbo is as fast as the 60GB products. The Onyx is slightly slower and the 30GB Solid 2 is twice as slow as the 60GB Solid 2.
Random Read & Write Patterns
Now we will see how the performance of the drives in random read and write modes depends on the size of the requested data block.
The random read results roughly correspond to the read response time of the drives except for the Vertex 2 whose graph differs strikingly from the others. It is faster than the others on rather large data blocks but its performance does not scale up as rapidly as theirs on data blocks smaller than 8 KB and it falls behind its opponents as the consequence. Perhaps this is due to those mysterious ways of data processing which are meant to make the SSD more reliable.
Random writing repeats the results of the response time test, too. The only exception is the OCZ Vertex Turbo which is as fast as the 60GB models processing 512-byte requests. However, it falls behind the rest of the SSDs as soon as it has to process larger data blocks.