Multi-Thread Read & Write Patterns

The multi-threaded tests simulate a situation when there are one to four clients accessing the hard disk at the same time. The depth of the outgoing request queue is varied from 1 to 8. We’ll discuss diagrams for a request queue of 1 as the most illustrative ones.

This test has been a hard nut to crack for many HDDs. It is the Samsung HM250JI that fails now. This HDD keeps all right with one data thread but slows down dramatically when there are more threads to be processed. As a result, it is slower at processing multiple threads even than the MHX2250BT although the latter has a spindle rotation speed of 4200rpm.

The HDD from Western Digital is a leader again. The Hitachi has good results, too.

Western Digital’s drive is the only one to remain a confident leader while the others change places in the diagram. Being good at reading multiple threads, the HTS542525K9SA00 is the slowest of the 5400rpm drives at writing and even slower than the MHX2250BT at processing four threads. The HM250JI, on the contrary, copes well with writing multiple threads. Its performance with one thread is rather depressing, however, but it is easily explained if you recall this drive’s result in the sequential writing test.