I had a 470 but I couldn't go beyond resolution 1024x768, I know they are compatible but this thing left me puzzled.
I have an 8500 GT same result, I took the 8400 GS because in the past I had tried it and it was fine.
Now I have a resolution of 1680x1050, the maximum that can support my monitor.
Even a 6xxx is fine is the minimum required, as the minimum to play some 3D games are 512 mb of ram.