Emulating Patterns

A few patterns that emulate real-life disk applications are discussed in this section.

A heavily loaded workstation comes first.

The old Deskstar 7K250 wins this pattern with a considerable lead because it has a small access time and efficient deferred writing algorithms which are important for this pattern. The three most recent models with an enlarged buffer, including the Deskstar 7K1000, are lagging behind the dense group in the middle of the list.

The 7K1000 is slowest in the file-server mode, even falling behind the Deskstar 7K400 with enabled TCQ! It has a considerable performance hit at a request queue depth of 64. The Deskstar 7K250 is again in the lead while the others have similar results.

The new HDD doesn’t profit much from not having to perform any writing. Native Command Queuing doesn’t help it, either, while the Deskstar 7K500 Serial ATA has put this technology to good use and almost caught up with the Deskstar 7K250, the leader of our IOMeter tests.