Web-Server, File-Server and Workstation Patterns
The drives are tested under loads typical of servers and workstations.
The names of the patterns are self-explanatory. The Workstation pattern is used with the full capacity of the drive as well as with a 32GB partition. The request queue is limited to 32 requests in the Workstation pattern.
The results are presented as performance ratings. For the File-Server and Web-Server patterns the performance rating is the average speed of the drive under every load. For the Workstation pattern we use the following formula:
Rating (Workstation) = Total I/O (queue=1)/1 + Total I/O (queue=2)/2 + Total I/O (queue=4)/4 + Total I/O (queue=8)/8 + Total I/O (queue=16)/16.
The picture is most unusual because HDDs behave completely different in this test. The Corsair delivers stable results at any queue depth. As a result, it is slower than the X25-M models at short queue depths but is ahead of them at long queue depths.
Intel’s SSDs all behave in the same way. They are brilliant at short queue depths but slow down at a queue depth of 128 requests. The 160GB model (with newer firmware) wins at short queue depths while the 80GB model, at long ones. The X25-E is surprisingly the worst of the three. These SSDs have some problems in this test. It must be some flaw in the controller’s operation.
The X25-M and Corsair have similar performance ratings whereas the X25-E has the slowest rating.
The picture is different when there are write requests in the load. The Corsair delivers stable performance but is slower than the opponents among which the SLC-based model is superior. Intel’s SSDs are far from stable. Their performance is constantly fluctuating.
The Workstation pattern is a more variegated load and it provokes dramatic changes in the behavior of the SSDs although there are no serious changes in terms of our performance ratings except that the 80GB X-25M gives way to the 160GB model. Particularly, Intel’s SSDs now deliver stable performance, although the 160GB model suffers a performance hit as the request queue gets longer. Corsair is still on the losing side. It is now clear that it prefers to work under low loads.
When the test zone is reduced to 32 gigabytes, every SSD, save for the Corsair, has performance fluctuations. The Corsair loses its speed at short queue depths while the X25-E is slower at long queue depths. As a result, the X25-M models take the two top places according to our performance rating.