Two graphics cards conflicting

birdus

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Feb 16, 2010
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I just built a new machine from scratch using an ASRock AB350 Pro4 motherboard and a new video card, an EVGA GeForce 1080 SC. Since the 1080 has only one DVI connector, I decided to add my old card back in, an EVGA Geforce 9800 GTX+. I want to run my two monitors off the 9800 and use the 1080 to speed up rendering in Adobe Premiere and After Effects.

The system ran fine initially with only the new 1080 card installed. The problem is that after I added the 9800 back in and plugged both monitors into it, the monitors ran fine for a few minutes, but then it seems like the 1080 hijacked things. Both monitors went black with no warning. The 1080 had taken control. I reinstalled the 9800 driver and both monitors worked fine when plugged into it, but then again, after just a few minutes, the 1080 took over and I had to plug a monitor back into it—nothing at all coming out of the 9800.

In fact, when I go into Display Settings->Display Adapter Properties, it doesn't even see the 9800. It just shows the 1080, as if the 9800 isn't even installed.

How can I set the 9800 to be the feed for my two monitors and just use the 1080 for rendering?
 
You have two videocard slots in that motherboard, if the computer sees the 1080 as the main videocard then maybe if you switch the slots each card is in the computer will then see the 9800 as the main card.

It seems easier to me to just use an adapter to have the 1080 do everything. But then, I'm not a big fan of trying to use an old card as an 'extra', it usually leads to more headaches than it's worth. You've obviously built a very nice new system...but you just can't let go of your trusty 9800 GTX+ can you? lol
 

birdus

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Feb 16, 2010
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18,510
Actually, it has to do with impatience. :) I had already ordered DVI-to-DisplayPort adapters (since I have two DVI monitors and the 1080 has only one DVI port), but wanted to get both monitors running while I wait. If it comes to removing and swapping both video cards, I'll just wait for the adapters and just plug both monitors into the DisplayPort ports (or one into DisplayPort and the other directly into the DVI port). In any event, I'm not going to mess around with the expensive 1080 any more than I have to.