Multithreaded Read & Write Patterns
The multithreaded tests simulate a situation when there are one to four clients accessing the disk at the same time – the clients’ address zones do not overlap. We will discuss diagrams for a request queue of 1 as the most illustrative ones. When the queue is 2 or more requests long, the speed doesn’t depend much on the number of simultaneously running applications. You can also click the following links for the full results:
Our multithreaded tests often prove to be an extremely difficult trial for hard disk drives, but SSDs find them rather easy. They don’t care what exactly memory cell to access. Moreover, the multiple threads produce a kind of a request queue, allowing to read simultaneously from two different flash memory modules. As we can see, most SSDs increase their performance at multithreaded reading rather than otherwise. The Intel X25-V and the OCZ Colossus are the only two products to slow down.
So, the RAID0 with two Corsair drives is in the lead, followed by the Crucial (which performs better with SATA600 than with SATA300 in this particular test). Next goes the Colossus and the rest of the SSDs.
The RevoDrive is slow with one thread but gets closer to the leaders when reading two data threads. It looks like the load is not heavy enough for this product to show its best.
As the number of data threads grows up, the RevoDrive climbs higher in the standings. The opponents help, too: the RAID array built out of two Corsair SSDs slows down at four data threads and the Crucial is irresolute as to what interface is better for it.
Multithreaded reading is difficult for HDDs but multithreaded writing is such for SSDs. There are two SSDs that suffer the most when writing two threads: the Crucial slows down with both interfaces, giving way to the single-chip SandForce-based products. The OCZ Colossus has an even bigger performance hit, though.
The RevoDrive is not troubled by the increased number of data threads and the Crucial is trying to catch up with the leader (this SSD now prefers the ICH controller again). By the way, this is one of the few tests where SSDs do not deliver high speeds and do not have an advantage over hard disk drives.
As for the other products, the Vertex 2 is undecided as to what firmware version is better for it. The Agility 2 is as fast as the other SSDs with the same controller (its smaller capacity must be the reason for the small gap). The low-capacity G.Skill is worse, even though ahead of the Intel.