Hard Drive Speed

[Alan Cox]

> Have you tested that? It's not clear to me that that should be so. 
> Physical characteristics determine the number of platters that can be in 
> a drive, and you generally see a manufacturer release several drives of 
> different capacity at the same time.

What makes the difference is the number of heads.

A 320GB array built of 8 x 40 GB disks has 8 sets of heads and can do a
lot more ops/second as a result. It can als have 8 outstanding commands
at a time unlike any pre NCQ 320GB disk.

Alan