Does running multiple monitors decrease performance?

[PCJake]

Hello everyone, I'm currently running three monitors (1 main monitor at 1920x1200 and 2 extras at 1024x768). I have my main monitor plugged into my GTX 280 and the two extras are plugged into an 8400 gs that I got recently (so I could use all three monitors). I've got a GTX 580 on the way to replace the GTX 280.

Will running three monitors at once affect gaming performance (and temps)? I have read that it can be a problem with the GTX 480, but I wasn't able to find anything about the GTX 580. Thanks.

 

[3DVagabond]

It shouldn't since you are only running one monitor off of the 280/580.

 

[PCJake]

It shouldn't since you are only running one monitor off of the 280/580.

I am curious how that works; I noticed when in EVGA Precision that the 8400gs was doing all the work when I was watching a video on one of the two extra monitors (while the GTX 280 did the work on the main), but when it came to Furmark it didn't matter which monitor it was on, it was always being rendered with the GTX 280. Is this because each monitor is processed by the graphics card it is plugged into except in the case of OpenGL/DirectX applications? Are such applications always processed by the main GPU no matter what?