how many graphicscard can i have in a pc

Solution
Windows limits only 4 GPU's from what I herd, but I think its more of a driver limitation. Only reason I can think they limit to 4 is because most motherboards and cases are to small for that many GPU's. There really in no point in adding more then 4 anyway. I have a friend with 4x HD6970's and it scales bad in a lot of games other then Battlefield 3 & 4. But 3 of his cards run really well in most games.

I run 3 GPU's, 2x HD5850's and a HD6450. Only reason I do is becuase the HD5850's both have a dual monitor flicker problems, Only way to fix that is to force my cards to run in 3d mode, it saves more power to run 3 cards but let powerplay kick in.

I remember seeing some guy post a build log type thing where he had 4 690's in his system and the replies were all people just laughing at him.
 
Windows limits only 4 GPU's from what I herd, but I think its more of a driver limitation. Only reason I can think they limit to 4 is because most motherboards and cases are to small for that many GPU's. There really in no point in adding more then 4 anyway. I have a friend with 4x HD6970's and it scales bad in a lot of games other then Battlefield 3 & 4. But 3 of his cards run really well in most games.

I run 3 GPU's, 2x HD5850's and a HD6450. Only reason I do is becuase the HD5850's both have a dual monitor flicker problems, Only way to fix that is to force my cards to run in 3d mode, it saves more power to run 3 cards but let powerplay kick in.
 
Solution