I'd assumed a speedup due to a) new drive did not have a r/w head (which allegedly, is more massive and therefore sucks at seeking) and b) sata vs. pata.
But the bottleneck is probably just the media itself. Plus my mb only does sata 1x anyways.
I can't remember and it's not embossed on the trays like they used to be. ISTR they were about the fastest on the market for standard kit a couple of years ago.