Chieftec Power Supply 8800 GTS Problem With Low FPS?

8800 GTS problem with low FPS? - chieftec power supply

I installed a new video card in my computer - XFX 8800 XXX 320 GTS. After installing Windows XP Pro SP2 after the full format C: \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\ \\. I installed the latest drivers and I am very low FPS (5-30) in Quake 4, NFS Carbon and other games similar requirements, 1024x768, detail. I Athlon 64 X2 4200, 2 GB RAM 1000 MHz and 450 Chieftec power (a property). What's happening? Why is the number of FPS so bad?