Random readsStill with IOMeter we took a reading of performance during random reads by blocks of 4 KB on the whole SSD after it had been filled with incompressible data.
These readings were carried out with between 1 and 32 simultaneous accesses over two minutes, which allows us to highlight the ability of SSDs to process these accesses in parallel. However, given that in standard usage the number of simultaneous accesses is most commonly between 1 and 4, we have only given results up to 8 commands to make the graphs more legible.
For information, in addition to random accesses we have also given the values for the same accesses when carried out sequentially.
[Random 4 KB reads: IOPS ] [ Random 4 KB reads: MB/s]
[Sequential 4 KB reads: IOPS ] [ Sequential 4 KB reads: MB/s ]
The fastest SSD on random accesses is the OCZ Vertex 4, closely followed by the Crucial C300 and the Plextor M3 and M3P. Overall SandForce SSDs don’t do very well here when the exercise is carried out across the whole SSD (they do better on a reduced area), but the OCZ Petrol brings up the rear a good way behind the Octane.
If we look at the same accesses when carried out sequentially, the Samsung 830 dominates with a single command, the Crucial M4 with 2 and 4 and the Plextor M3 and M3P with 8. Two of the SSDs however behave rather strangely: the Kingston V200 isn’t any faster with sequential accesses than random and the Vertex 4 is actually slower with sequential accesses! There’s obviously an issue with the firmware here, given the performance gap to competitor SSDs.