Just curious about the speed of the newer extral-large capacity hard drives. Are bigger drives necessarily slower than smaller drives?I guess my question refers to seek time although I'm really interested in the time it takes to transfer large files from one drive to another. Thanks for any light you can shed on this question.
There are two primary factors that determine the transfer rate of hard drives: rotational speed and platter density.
The fast the platters spin, the more quickly data can be transferred to or from the drive.
The more data there is on each track, the more quickly data can be transferred (because one track is read on each revolution of the platters).
Whether a 1TB drive is faster or slower than a 2TB drive depends on whether it's construction is different in terms of rotational speed or platter density. For a given generation of hard drives, the manufacturer will typically build drives of several different capacities using exactly the same components and technologies but with different numbers of platters. For example, WD builds 1TB drives and a 2TB drives that both have the same RPM and platter densities - the only difference is that the 1TB drives have two platters and the 2TB drives have four platters. In this case the transfer rates are identical.
So the answer to your question is: it depends. If you're comparing a 1TB 7200 rpm drive to a 2TB 5400 rpm drive, then the smaller drive will be faster. But it's not faster because it's smaller, it's faster because it spins more quickly.