while everyone is making your choice rather clear, i would add that a HP from 2002 will almost certainly not have sata. so the ide is really the only choice here that would make sense. and rocketeer nailed it, if hard drives use ide (or they used too) and they are at least 10 times faster at data transfer than a cd-rom drive, then the ide interface is certainly not bottlenecking performance on your cd-rom drive.