XP 3ghz Quad core performing worse than single core 2ghz

I am running
XP Pro Sp2
GeForce 9800 GT 1 gig
4 Gigs 800mhz Dual Channel (3.2 after windows eats some of it)
Propus 640 x4 Running at Stock 3ghz on a 95tpw board
Whatever cheap SATA 1Tb low power hd Tiger sells with the swap on my old Seagate ATA 100 320 Gig (stuck in IDE)
I disabled the IDT HIgh def and put my old SB live in after sound crashes started to get me....
BioSHock experiences tears and stuttering
Silverfall sputters every ten minutes
Spring Stutters and has tearing like you wouldn't believe (by stuttering in this case I mean it goes FASTER every few seconds)
I've lost FPS on everything from NFSHP2, U2
Lost planets colonies stayed same frame rate
UT2k4 is doing better, but it is the only one.

Newest NVidia Drivers
Been through all the AA, Multithreading and usual NVCPL tweaks.
Latest Chipset drivers
No AV running

The only game that had discernible and trackable symptoms was Bioshock and that seemed to be related to a combo of drivers and Havok Settings.


I would love to resolve this and be able to game (it's what I bought it for), without going to 7 or reinstalling XP yet again. Just seems to me like adding 3 more cores, each one being faster than my old rig would make stuff faster, not slower and less reliable.

Any help would be much appreciated.

First things first. Is your XP recognizing all 4 cores? Do they show up in Task Manager?

I went ad got the windows 7 90 day thing. The performance is a little better, enough that the tearing and side of screen blur is almost bearable, but it still looks like everything is running under 32 fps.