How do discrete video cards actually work?

[curtkram]

Hi. I run 2 monitors, and use them for things like 3dmax and cad. I recently came across a new and better nvidia quadro video card but it only allows one monitor. My old dell pos computer only has one pcie x16 slot, so i modified an old video card to fit an unused pcie x8 slot. So I have a decent video card and a pos video card (also a quadro but older), each with one monitor connected.

Can anyone explain what the computer is doing with this? Say I'm running max on one screen and cad on the other, is the gpu from the nice card available to both, or does it depend on which screen the application is on? Are the memory and gpu from both cards available to any application? Is the older video card limiting the performance of the new one at all?

 

[ram1009]

I think you're on your own here, friend.

 

[alvine]

gpu offloads the cpu from graphic related tasks
i personally don't own nvidia quadro cards so i can't answer your question
in nvidia control panel are both video cards being recognized?

 

[guavasauce]

no, each gpu requests its own information from the cpu and displays what it renders. a descrete gpu is, for easy explination, a slave computer. the reason your set up works is: pcie allows use of lanes that connect to the cpu for data transfer. as long as data can reach it in a timely manor, youll get a solid picture. you could even put a pcie 16 into a x1 slot, and youll have 1 lane for data.

now, windows itself is what keeps you from doing anything on each screen simutainiously, or real time on both. windows only allows one window to be the main focus at a time, regardless of how many screens or gpus you have. however, running virtual machinices will alliviate this, with a slight performance degrade.

does this help?

 

[curtkram]

Yes, I it does. The pcie lane thing was fairly easy to understand with a bit of googling (i wouldn't have taken at it with a saw if i didn't think i understood that part). I have been unable to get information on the gpu/cpu relationship though; probably because I've been asking the wrong question.
So, if the GPU acts as a slave computer then the second video card in my case is adding a little to the performance of my computer. Neither the computer nor the video card care what monitor is plugged in where. Likewise, at home I have a nice graphics card that supports 2 monitors, but I plugged in the second one to an on board video card because I thought it would reduce the resources of the video card. That was pointless. And it's the motherboard that is managing resources rather than the os or drivers...

 

[curtkram]

Best answer selected by curtkram.

 

[Mousemonkey]

This topic has been closed by Mousemonkey