I don't know, to be honest. All I know is, my iMac 233 is very very slow (but it's only got a 4 GB HDD)--so that doesn't provide any information. My PC, on the other hand, has a few hard drives, one of them being 40 GB. It seems pretty fast. Without really knowing anything about it, I can't imagine that there would be a noticeable difference. Does anyone else have any input?