Help GTX 770 or 680 for 3,1 Mac Pro

[tsialex]

hi, I have one MP 3.1 and willing to upgrade my GPU, I will keep the old GPU for the boot, in this case what can be the fastest GPU?

thanks a lot...

GPU support depends on how you gonna power it and driver support.

With High Sierra and web drivers, GTX 1080/1080Ti, TITAN X.
With Mojave, Apple native NVIDIA drivers only work with Kepler generation GPUs: GTX 780/780Ti, TITAN/TITAN Black.

Mojave don't support two different GPUs, btw.

 

[lfgc.trader]

I need to connect 2 4k screens and my mac pro is 3.1, which video card is it compatible?

 

[orph]

just look at NVIDIA and AMD sites specks for each GPU and look at output rez with HDMI and DP
there's sticky topics in the forum with lists of GPU's that will work in your 3.1 depending on what OS you are on

this one is worth a go first
https://forums.macrumors.com/threads/gpu-compatibility-list-for-cmp.2174600/