HD Tach provides only two results, the burst transfer rate and the average transfer rate. We ran the “long bench” test from this program.
Here most disks achieved the same performance level, as you can see on the above chart. The only disks that were way off average were Hitachi Deskstar T7K500 (the other disks achieved transfer rates between 9% and 12% higher) and Samsung HD250HJ (the other disks achieved transfer rates between 17% and 21% higher). As you can see a larger buffer didn’t make any difference in performance on this test.
Here the two Seagate Barracuda 7200.10, Maxtor DiamondMax 21 and Samsung HD250HJ achieved the same performance level. These disks were around 6% faster than Western Digital Caviar SE16, around 10% faster than Hitachi Deskstar P7K500, around 14% faster than Western Digital Caviar SE, around 25% faster than Seagate Barracuda ES and around 63% faster than Hitachi Deskstar T7K500.
Again the higher buffer made only difference for the Western Digital hard disk drive, where Caviar SE16 was 7% faster than Caviar SE.