VR with SLI for rendering and integrated graphic for monitor?

Ok, i got a vr setup with two 1080 and vive hmd, but i got vive and monitor both plugged in the main graphic card: would plugging those in the mobo increasing performances?
I mean, the graphic card could work just for the rendering job, without bothering to work for the monitor or sending final render to the vive.

i’m asking because using nvidia-smi tool i noticed one of the graphic cards always have a certain amount of work more than the others, i’m talking about 5 to 10% more, that’s not a huge amount, but it could possibly became a problem when developing my vr project.

Does it make sense to anyone?

EDIT 1:
done the test (plugged monitor to motherboard), now i got gpu 0 at barely 10% while gpu 1 going normally and nVidia Control Panel won’t open: “nVidia monitor settings are not available - Currently no monitor plugged to a nVidia gpu is being used”.

Does this mean that i’m forced to have a monitor plugged to a non-dedicated gpu to have sli being correctly working even if i’m on vr (so i’m not going to use my monitor to play)?

Hello, did you succeed in running SLI with HTC Vive on the UE project? Just yesterday I tested a set with two 1080Ti and always worked only one card. I tried to change the settings in the Nvidia Controll panel but without success. There are plenty of old articles and discussions on the VR SLI on the Internet, but I can not find any recommendations that would be for the UE 4.18+ and would work.

Unreal doesn’t support SLI by itself, you need to download and compile the nVidia VR Works branch of UE4 from its github page, you can find all the information here

Actually i forgot to be more precise on this aspect of the question, but i was asking for a specific setup given my sli configuration was working correctly.