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 these links to view the tabled results:
We will build diagrams for request queue depths of 1, 16 and 256.
It is the 7200RPM drives that come out the winners at the shortest queue depth and high percentages of reads. The Hitachi 7K500 is also very good at high percentages of writes, being only inferior to the splendid 500GB drive from Western Digital there. The Seagate 7200.4 is not fond of writing at all, just like the BPVT series drives from WD which are slower than their predecessors.
We can observe some unexpected changes in the standings at the longer request queue depth. We have two 5400RPM drives – the WD BEVT and the Seagate 5400.6 – contending for top place. Interestingly, their 640GB successors are both worse at writing, the 640GB WD BEVT being also rather poor at reading. The HDDs with Advanced Format are still the worst overall, especially at writing. The Seagate 7200.4 is slow at high percentages of writes, too, although boasts highly effective reordering of read requests.
We don’t see any more changes in the standings when the request queue gets even longer.