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Database Patterns

In the Database pattern the drive is processing a stream of requests to read and write 8KB random-address data blocks. The ratio of read to write requests is changing from 0% to 100% with a step of 10% throughout the test while the request queue depth varies from 1 to 256.

You can click this link to view the tabled results for IOMeter: Database pattern.

We will build diagrams for request queue depths of 1, 16 and 256.

We’ve got an interesting picture at the minimum queue depth. The Corsair is better than its opponents at high percentages of reads, but rolls back to last place at high percentages of writes. The Intel X25-E is just the opposite. Take note of the jagged graphs of all the SSDs from Intel: they are obviously trying to adapt for the load during this long test.

When the queue depth increases (although it is hard to imagine a situation when such a fast drive would need a requests queue), it is the Intel X25-E that goes ahead. This model is obviously up to its enterprise targeting and worth its high price. The Corsair takes last place.

There are no big changes when the queue gets longer except that the two X25-M models get closer to the leader.

Winding up this group of tests, we will show you diagrams for each SSD with graphs for five different request queue depths.

Frankly, we did not expect an SSD to deliver such a repeatable result. The behavior of the Corsair is easy to explain. It begins to reorder requests when there appears a request queue. This improves its read performance but worsens its write performance.

Although drawing different graphs, the two Intel X25-M models behave in a similar way. They are not very fast at short queue depths, but have very effective request reordering algorithms. As opposed to the Corsair, their speed of writing does not deteriorate at that.

The Intel X25-E behaves in a similar way. It wins more than the others from having a request queue and has an excellent performance boost at reading. This HDD obviously prefers high loads. It is an enterprise model indeed.

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