Multithreaded Read & Write Patterns

The multithreaded 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. When the queue is longer, the speed depends but little on the number of applications.

This test has always been a hard trail. Seagate’s 3.5” HDDs are in the lead when processing one thread (and the 7200.10 enjoys a lead of 10MB/s over the others), but find themselves the slowest at two threads, having very low speeds. The Hitachi 7K200 is the best drive to read multiple threads, being two times as fast as the previous-generation 7K100 and six times as fast as Seagate’s HDDs.

The gaps between Fujitsu’s HDDs are smaller when there are more threads to be processed, yet they are still ranked up according to their spindle rotation speed.

Take note that the Fujitsu MHY2 BH and the Seagate 7200.1 deliver similar performance when reading one thread: the higher recording density of the former makes up for the latter’s higher spindle speed. This shows the influence of recording density on a HDD’s performance. Performance being the same, a HDD with a lower spindle speed is going to be preferable for notebook owners due to its low power consumption.

Seagate’s HDDs are not as utterly hopeless at multithreaded writing as they were at reading. When writing one thread, the HDDs are ranked up exactly as they were at sequential writing. The three HDDs from Fujitsu perform proportionally to their spindle rotation speeds. The Hitachi 7K200 is surprisingly slower than the 7K100, while the Fujitsu MHW2 BJ proves to be the best among the 2.5” models.

When writing two threads, the low-recording-density Seagate 7200.7 takes first place – somewhat surprisingly. It is followed by Seagate’s other two HDDs and by the Fujitsu MHW2 BJ. The Hitachi 7K200 doesn’t slow down much and now outperforms the 7K100 as well as the 5400rpm Fujitsu MHY2 BH.

The leader remains the same at three threads but the Fujitsu MHW2 BJ is getting farther away from Seagate’s duo, in which the 7200.10 loses more speed than the 7200.1. Hitachi’s HDDs slow down considerably, the 7K200 being overtaken by the Fujitsu MHY2 BH.

Increasing the number of threads further makes the Seagate 7200.7 slow down. The Fujitsu MHW2 BJ becomes the leader.

Do you often have to write data in multiple threads? Now you know what company’s disks are the best for this job.