Monitor loosing signal

[theturn]

So I just added a second video card and now whenever I do any gaming after about 20 min or so I lose my connection and my monitors go black. Meanwhile the computer is still running. When I installed the 2nd card I removed the drivers and did a fresh install. As for temps I'm not seeing the cards get hotter than mid 50s. I'm only using one bridge but maybe its a motherboard thing. Both monitors couldn't be more different so I'm positive my monitors are not the problem. It stopped crashing on Black Ops MP when I lowered the anti-aliasing from 8 to 4. Playing Homefront today and it losses its signal just after the intro. Lowered the anti-aliasing to 2 on that and still crashed. I have now removed the 2nd card and I have had no crashing issues yet. So its either the power supply(650 antec) the 2nd card is bad, motherboard, or I was doing something wrong with the bridge. Gotta fo to work so I can't do any testing till I get back.

[Sephiracle]

Try the card you pulled out by itself, if it's running fine by itself then its not that.

[Deleted]

Try beta drivers to see if they work if not drop AA down to 0x and see if that works