what a nightmare, hard drives should never share, unless they are never going to used at the same time(talking to each other)
If I have 3 pata dvd burners in a computer, the 2 which will be used for on the fly are going to be on seperate ide's.
Your new computer needs to be benched by something that taxes the cpu/memory bus and is not bottlenecked with disk I/O.
try a video compression test from hard drive to hard drive on seperate cables
you won't read a dvd much faster than 5 minutes no matter what, hard drive to hard drive takes about 2 minutes for a little over 4 gigs, but fast memory or fast cpu is not needed
convert an avi to mpeg2 or try a 55% compression of mpeg2 and then your upgrade will slaughter your older computer
3dmark and aquamark are fun to run also, then you get to see video components having a play