Originally Posted by Gentle
This may be a design limitation. Does the AGP variant still rely on a HSI chip to translate from PCIe to AGP? If so, these produce lots of heat. Heat is one of the limiting factors for overclocking.
No, it's using the classic NV40 -- no bridge.
The BIOS being shipped with the XFX 6800 GS AGP is fairly old - 5.40.02.15.10. Aluminum cooler as well.