emulators better on older computer?

one day my gf was using my good computer to play second life, well i was bored so i asked to shut it down so i could take out my 2nd hard drive with my playstation emulators etc on it so i could use it in another system, now heres the specs of the she was using and the specs of the one i was using,

Good Computer

AMD 3500 2.2ghz with 1.5gigs of ram, 250gig hd and a ATI Radeon X1600 512mb

Older Computer
AMD Athlon XP 1.6ghz with 512mb of ram, 8gig hd and a Geforce MX440 64mb video card.

now for some strange reason and maybe someone can tell me why but my emulators all played better on the older machine than my newer at the same settings etc, why i dont know, but i just find it odd and was wondering if someone may have an answer.

I don't know if emulators are even allowed to be discussed, but most likely you messed up your config. Emulators scale almost linearly with CPU, and GPU doesn't matter at all for PSX emulators.