Something tells me Fistful doesn't have an 11th generation Seagate 7200.11 spinning high-rpm vortices into the local space-time continuum. Call it a hunch.
Yes, a slower HD may read pagefile data into the IDE bus slower than the heads seeking both pagefile and OS data on a common drive.
Monkeys may fly out of my posterior, too. In fact, when I was under general anesthesia for surgery last year, they may very well have. I wasn't there, so it's entirely possible. I remember my ass hurting afterwards, but it may have been an episode with an overly amorous male nurse in the recovery room for all I know. Nobody's talking, so I'll probably never know. I'll stick with the monkey story, regardless.
IOW, Fistful never said what spare drives he has to experiment with, and I didn't start this thread promulgating a second HD as an alternate pagefile storage medium. I say there's no harm in letting him experiment. If he sees no visible improvement, no harm, no foul. Google "relocating XP pagefile" and you'll see a wide variety of responses. Some contributors are hacks, some I'm sure are PhD's who could teach Bill Gates and Steve Jobs a thing or three. YMMV, and all that.
Some folks say that if you have enough RAM, you should disable the Windows XP pagefile entirely. I see no wisdom in that with respect to the way virtual memory works, but hey...