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 the IOMeter: Database pattern.
We will build diagrams for request queue depths of 1, 16 and 256.
At the shortest queue depth, the X128 is slower than the X25-M or P128 at very high percentages of reads. It is, however, better than the other Corsair and competes with Intel’s product at high percentages of writes.
The JMicron-based models are good at reading only. Although not as fast as their opponents, their reading performance is much higher than what you can get from an HDD. But as soon as there appear write requests, these SSDs slow down almost to a halt. The speed of less than 10 operations per second is a disaster. The Transcend with SLC memory delivers 20-30 operations per second at high percentages of writes, but this is still much lower than with any modern HDD.
When the request queue gets longer, the X25-M goes ahead, the X128 taking its deserved second place.
Next we will show you diagrams with the performance of each new SSD at five different queue depths. Such diagrams are most illustrative when it comes to SSDs.
One look at this diagram would tell us what controller is installed in this SSD because we saw a very similar diagram with the OCZ Vertex Mac Edition. So, this model has got an excellent controller with superb firmware that can effectively process write requests and make a good use of the request queue.
These three SSDs produce very similar graphs. And we have to note that their controller does not see the depth of the request queue and can only perform fast enough when processing read requests. The use of SLC memory in the Transcend model does not save the day: the drive only shows a somewhat higher performance at high percentages of writes and is faster under mixed loads with a larger share of reads.