Sequential Read/Write Patterns

Now let’s check out for any surprises at simple reading/writing of sequentially located data.

You can see improvements here. The record performance of the oldie Deskstar 120GXP is finally surpassed. The speed reduction when processing small-size data blocks, which we first saw in the Deskstar 180GXP and which became much worse in the Deskstar 7K250/7K400, has finally been dealt with. Moreover, the Deskstar T7K250/7K500 HDDs achieve their maximum speed on 2KB chunks (the best result ever shown in our labs) and deliver two times the speed of the 7K250/7K400 models. This acceleration cannot be only due to the increase in the clock rate of the electronics from 133 to 166MHz.

The 7K1000 and T7K500 have inherited all those helpful features and added to them their high speed of processing large data blocks. The 7K1000 achieves an unprecedented 82MB/s and the last generation of longitudinal recording from Hitachi, represented by the Deskstar T7K500, isn’t much slower. Interestingly, these HDDs seem to get a second wind when the data block size gets larger than 8KB.

We’ve got a similar picture at sequential writing, too. The two newest models are somewhat slower than the previous-generation leaders when processing small blocks but deliver a considerably higher maximum write speed.

The outcome of this test holds a promise of high performance of the new HDDs in NTFS where most operations are performed over small data blocks.