Trying to start nvidia sli

Hello All,

I’ve got 2 NVidia GTX 970 graphics cards in my system, on an X99-A motherboard, hooked up to a Samsung U28E590 28" 4K monitor.

I have been trying to get SLI working to boost my framerates, but I have not been able to.

I am using the proprietary drivers (375.66), and the SLI cable is connecting the 2 cards. When I open the NVidia Settings app, there is no option for SLI. It does show that both cards are detected properly, and so is the monitor.

I have tried manually to turn SLI on using “sudo nvidia-xconfig --sli=on”, but sometimes I get a black screen on bootup, and sometimes crazy screen tearing/stutters when I get to X.

I have used the same hardware on Windows 7/8 and have had SLI on, so I know it works.

Can someone show me what I have missed?

Thanks,
Chris