HELP! 4k monitor uses intel hd graphics and not my gtx 960

[gohomecookrice]

Im all out ideas guys, I have horrible fps on this new 4k samsung monitor that I bought and I cant switch over to my gtx 960.. Ive tried disabling the intel driver and it just makes my monitors screen go black, I've tried uninstalling and reinstalling that didnt work either. My other 1080p monitor is using my gtx960 fine i just dont understand why this monitor cant use it... *pulling hair* please help guys!

 

[Brunostako]

Is your 4K monitor connected to the GTX 960?