I just bought a new graphics card to upgrade what I had for the 1st time in life. The problem is that none of my games will now run and I don't know why or how to diagnose the problem. For example, World of Warcraft says - WoW was unable to start up 3D acceleration. Steam wont even load up. Civilization 4 says: Initialized Renderer failed. Check DirectX Installation, Latest Graphics Driver and Graphics Settings.
What I had before was ATI Radeon HD 4870 512 MB (2 x 6-pin cables). What I bought and upgraded to was AMD Radeon HD 7970 Mac format graphics card (1 6-pin and 1 8-pin cables). I installed the graphics card on my own. I changed out the old cables to the new ones. It was not clear which cable goes with which on the mother board in regards to the 6 and 8-pins. I've tried both ways with no success in switching cable ports if it mattered. I'm currently running OS 10.7.5. One place poking around looking for ideas indicated that I may need to upgrade to OS 10.8.3 for graphic card drives for the 7000 series. Otherwise, I'm a total noob in the dark about this stuff and came here looking for answers. Let me know if more information is needed to help me with my problem.