Good day,
I am unable to start a monitor on any of the Displayport connections on my EVGA GTX950. I am only able to drive a monitor from the DVI connection and when I try to setup a dual-view connection with a monitor on the DVI and a monitor on one of the Displayport connections the monitor on the DisplayPort cannot detect a signal and eventually suspends. I am using the DisplayPort cable that came with the monitor and so I do not believe it is a cable/monitor combination problem. This problem is present right from boot up.
Kind regards,
Craig
 
Kernel : Linux 3.13.0-24-generic (x86_64)
Compiled : #47-Ubuntu SMP Fri May 2 23:30:00 UTC 2014


-Display-
Resolution : 3840x2160 pixels
Vendor : The X.Org Foundation
Version : 1.15.1
-Monitors-
Monitor 0 : 3840x2160 pixels

-OpenGL-
Vendor : NVIDIA Corporation
Renderer : GeForce GTX 950/PCIe/SSE2
Version : 4.5.0 NVIDIA 352.63
Direct Rendering : Yes
 
 

I would try a different DP cable just in case. For some reason I see a lot of defective cables. I got lucky and never had any problems with my DP cable and it was the cheapest one that T-D had in stock.

also did you or can you try  using the display port/hdmi 's ?     if you google this issue  like you described  you will see a lot on it    seems to be pretty common 
 
[example ]
 
https://steamcommunity.com/discussions/forum/11/624075374635565403/
 
https://forums.geforce.com/default/topic/863996/gtx-980-ti-won-t-detect-any-monitor-plugged-into-the-dvi-port-once-the-driver-is-installed/
 
http://www.tomshardware.com/forum/id-2416510/monitor-working-display-port-work-dvi.html
 
read up and see what solves they came up with  , this has been ongoing with the 900 cards   plenty to look at ?
 
I like this
https://forums.geforce.com/default/topic/820580/gtx-960-does-not-support-dual-monitor-/
 
and why I suggested  use 2  ports not dvi-I   hdmi and hdmi or hdmi display port or display port and display port ??     like that guy kinda said maybe the analoug part of the dvi-I gets things mixed up ??
 
lots of guys in this same boat as you
 
good luck