Access timesWe measured average access time with IOMeter, using random 4 KB accesses. So as to view the potential gains linked to NCQ, these accesses were carried out with 1, 2, 4 and 8 simultaneous commands.
In contrast to the 2 TB models, the 1 TB drives have pretty good access times. At worst we were at 15.5ms on the EcoGreen F3, against 15.1 ms on the Barracuda LP and 14.5 to 14.7ms on the Caviar Greens. With 12ms the Caviar Black WD1001FALS had the best score, closely followed by the WD1002FAEX at 12.4ms. The Barracuda 7200.12 is the slowest of the 7200 rpm drives with an access time of 13.8ms.
NCQ does a good job with reads but we noted that the Samsung drives didn’t optimise accesses with two simultaneous commands, in contrast to the competition. To put this in context, with 8 commands a very good SSD such as the Crucial C300 128 GB is around 280 times faster!
We carried out the same test for writes. The scores we got were much better for hard drives because of the fact that they have a write cache, which however renders NCQ useless. The Caviar Blacks are at the head of the field, followed by the 7K1000.C. The Seagate drives lag here with the 7200.12 behind the LP!