Geforce 8800GT on a AMD Board

[TheHamburglar]

So a few months back a bought all the parts and built a new computer Building a New Rig. Thing is my FPS only go to about 30 on my driver when I have all 5 toons going, I'm using Keyclone and have the alts set low with 10 fps settings. My main it set 50 and 15.
I was wondering if the problem might be that I'm using a Nvidia card on a Motherboard built around an ATI card?

[Qlimax]

I run a 6400 dual core with an 8800 ultra and I get around the same fps but Im at 2560x1600 (split / 5). Ill have alts set at 7 fps and get 34 on main, alts set to 15 get 25 ish on main