Three 4K ( 3840x2160 ) displays on GTX 960 causes black flicker on third.

I intentionally purchased the GTX 960 with 3x DisplayPort 1.2 interfaces, one HDMI 2.0, and one DVI interface, anticipating three 4K displays each running at 3840x2160@60Hz.

I am using version 346.72 of the driver, with Kernel 4.2.5. But I used 4.0.9 until this issue started. I am unsure which Kernel version I need to use to be able to use +355.* of the driver. I am using Mint Linux 17.2 with X.Org X Server 1.15.1 currently.

For a while I was just using one P2715Q. That was great quality at high resolution, and I had two 1920x1080 displays going also ( via the HDMI and DVI ). Then when I took the plunge into three 4K displays, all Dell P2715Q displays. They all worked… for 30 seconds, without extra configuration.

Then, the third display started flickering - but so profoundly it was as if it actually turned off. It had a nasty black flicker. It happened once, then 5 or so seconds went by, then it started flickering black every few seconds until eventually it would just stay black.

So far the only remedy I’ve found is to run the third display at 2560x1440@60Hz.

Is there some kind of limitation I’m hitting, whether on a driver level or hardware level?

My GTX 960 has 1024 CUDA cores, 4gb of RAM, and so far I see it only using 43% of that RAM… and 5% of the GPU in its natural “desktop only” state, versus gaming or anything too intensive.

Thank you very much for whatever help can be offered.

The symptoms you’re describing sound kind of like a DisplayPort signal integrity problem. Does the problem go away if you enable only the third monitor in the control panel? If not, then if you rearrange the cables between the monitors, does the problem follow the monitor, the cable, or the port on the GPU?

Good senses – disabling both the other monitors and setting the third to a resolution of 3840x2160@60Hz does cause the failure, as if it the others were on, and at that resolution too.

Now I will test further.

Ruled out the cable, and ruled out the monitor. So it’d need to be the port then – which I am about to test. If it’s a bad port – can I daisy chain two P2715Q monitors then?

Not sure how I mistook this, or how I missed it before – but it was actually not the port, it was one of the cables. So this is solved! Thank you very much! Enjoy paternity leave :)

Hi Digitalextremist,

I’ve been trying to get my 3 4K monitors to run at full 4K@60Hz and its been dismal. Are you currently running all three monitors at 4K@60Hz? How do you deal with the split screen or dual tile issues? Were you able to actually get all three monitors running at 4K@60Hz under linux on a single card? If so, please let me know what you did since I can seem to get it going for reasons which I thought were low level hardware issues, not software configuration issues.

thanks. Steve.

“Maximum Digital Resolution* 5120x3200”

GeForce GTX 960 | Specifications | GeForce
http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-960/specifications