If your BIOS has a setting to set the AGP rate to 1x or 2x try that. It can help avoid motherboard replacements.
Bob
rosewill 600w powersupply is Enough power
7900gtx will not play any games and locks up and resets constantly!
there have been times where computer switched to 256 colors and said nv4_disp stopped functioning correctly ONLY when Windows media player was the only app running!
nvidia control panel reports GPU temp has never topped over 59degrees...
so, im thinking BIOS issue but it could be RMA time, any other suggestions?(dont even tell me its a driver prob.,been there done ALL)

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