Performance in Intel IOMeter
Sequential Read & Write Patterns
IOMeter is sending a stream of read and write requests with a request queue depth of 4. The size of the requested data block changes each minute, so that we could see the dependence of the tested drive’s sequential read/write speed on the size of the processed data block. This test is indicative of the maximum speed the drive can achieve.
The numeric data can be viewed in the tables below. We will be discussing graphs and diagrams.
It’s simple with the top speeds of reading. The two SSDs from the Performance series and the junior (32 and 64GB) models of the Extreme series are about as fast as 200 MBps whereas the others are close to 250 MBps. There is no real competition when the SSDs process small data blocks: the new SandForce controller accelerates faster than the others as the data block size grows up.
Interestingly, its performance is so high on small (up to 4 KB) data blocks that it loads our testbed’s CPU by 95% with requests processing (there are about 30 thousand requests per second!). Well, such loads are rather theoretical ones because there is no reason for any application to read sequentially located data in such small chunks, yet we are really surprised to see our CPU almost suffocated by disk subsystem requests.
Another surprise is the performance of the Reactor. It outperforms many opponents on all data blocks, leaving the Performance series behind, for example.
The results are much more varied at writing. Like the OCZ Vertex 2 in our previous review, the SandForce-based SSD does not meet our expectations and stops far from the specified top speed, delivering a write speed of only 133 MBps.
Then, the Extreme series shows it clear enough that there is a difference in performance between different-capacity products which is roughly equal to what the manufacturer declares. We should also note that the Indilinx-based products reach their top write speed on 16KB data blocks and then slow down a little on larger blocks. The Nova copes better but we don’t know if this is due to its different flash memory chips or some changes in firmware.
The Performance and Reactor series drives are competing for top places. Their performance on large data blocks depends on the particular size of that block, which is due to some imperfections in their controllers. Or rather the performance depends on when and how the controller erases the memory cells.