3870 on socket 939 issue

hello,

i am in the process of upgrading my pc after 4 years, and bought a video card first... the HIS 3870 iceq3. after plugging it into my socket 939 system (athlon64 4000+) running on a radeon 200 motherboard with pci-express 1.0 it hangs my system.

i can still boot into windows vista 32 and install catalyst, but the cpu seems like its throttled and running very slow even at 100%. when i insert my old gfx card, the cpu works fine.

i have a 450 watt PSU, so that shouldnt be the issue... any other ideas?

actually i dug around and seems like there is an irq conflict. the 3870 has a goofy HD audio device baked into it.

somehow... i need to disable that device to free up that irq. i forgot to mention that i have a creative x-fi which is probably trying to hog that irq.

anybody know how to disable/move irqs at the motherboard level? i set my bios to PNP OS.