You are correct. I have the 8800GTS G92 on my 975x board. No problems, runs like a champ. Some of those intel boards run better than nvidia boards as well. Granted you get what you pay for, just can't run SLI which is a bummer for future.
I recently bought a Gigabte 790XT AMD mobo with crossfire support. I tried to use an older card, Gigabyte 9600GT, and i faced some severe problems:
1. While installing the drivers (the latest one from nvidia site) the pc freezed. After restart the drivers seemed to be installed correctly. However, after a second restart the drivers had gone but the graphics card was yet recognised as 9600GT. After many tries the drivers have installed and stayed there. But the whole systems freezes periodically and without reason , for example while browsing or while typing a text. Is there any idea about mobo-gpu compatibility?? Is there anything else i should try??