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% throughout the test.
We built three diagrams for different request queue depths to illustrate performance of the HDDs in this test.
At a request queue of 1 the HDDs all begin at the same speed in the random read mode, but the HD-227U2 gains the lead when there are more writes to be performed. It is followed by its brother that concedes second place to the Transcend at 100% write requests only. The external HDD from Western Digital takes no part in this competition, being firmly seated at the bottom of the diagram.
The request queue depth is increased to 16 outstanding requests, but there are no changes in the HDDs’ standings: the HD-227U2 is the leader while the WD Passport is the loser. The Transcend seems to have problems when the queue contains 20-30% of write requests.
But now it’s hard to name the winner. The Transcend StoreJet wins in the random read mode, but then the two brothers with different interfaces take the lead. The StoreJet regains its leadership when there are more writes than reads in the queue. The WD still doesn’t take any part in the competition for the podium.