I recently bought a Sapphire HD 7850 1GB graphics card but I can not get it to work. It looks like it's not recognized by the system. I can boot my PC fine with the screen connected to the GPU of the motherboard, but when I then look at devicemanger or MSINFO32 it looks like the system has not recognised anything but the GPU of the motherboard. There is no unknown device or HD 7850.
The 6-pin power cable (of a coolermaster 600 watt PSU) is connected and the fans are spinning. It is not the slot in itself because when I put my old graphics card (HD 5700) back in, it works fine.
I have also upgraded the bios to the newest version (0505) but to no avail. In the bios settings "PCI-E" is set as the primary graphics boot device.
My motherboard is a PN5-EM HDMI which has (I believe) a PCI express x 16 version 1.1 slot. There is a lot of conflicting information on this but I understand that for most cards (especially NVIDIA) they are all backwards compatible. But for the power-saving AMD cards for example I might experience compatibility issues.