GTX 970 displayport does not work, even at boot

[jonathanrk]

I have now tried two different EVGA GTX 970 boards (an ACX2 SSC with 4xDP and an ACX2 SC with 1xDP) in a new build. They work smoothly as expected over HDMI, but never appear to drive *any* output over DP:

- Nothing appears on the display over DP, even during POST/while showing UEFI config screens.
- Nothing appears on the display over DP in Windows (10), running the current drivers.
- The output is not detected by the drivers in Windows: when running (and behaving as expected) over HDMI, additionally plugging in DP, before or after boot, shows no additional detected outputs in the display configuration.

This is with a Dell P2415Q (4k) display, using two different cables on each of two different DP inputs.

Has anyone else had similar trouble? Google is full of people having trouble with DP ports flaking out on sleep, etc., but this happens 100% of the time, even before the drivers are ever loaded—it seems they just don't work at all, on multiple (similar) cards, with multiple cables.

This is on a Gigabyte GA-H97N-Wifi, configured to use 'PCIe 1' as its initial display output.

 

[krells]

I had a pair of strix 970s that worked flawlessly over dp. When swapped out the cards for gigabyte 980s and had the same issues you are having. For me my display port works for a second display, it just won't boot into windows with the display port as the primary display.

 

[jonathanrk]

I had a pair of strix 970s that worked flawlessly over dp. When swapped out the cards for gigabyte 980s and had the same issues you are having. For me my display port works for a second display, it just won't boot into windows with the display port as the primary display.

So: it's the Gigabyte 980s where you can only use DP for secondary display? Do you see BIOS screens over DP, or is it just in Windows that you have this trouble?

Thanks!

 

[krells]

When I first installed the card I didn't even see the bios screen over DP. I tried a fix online that seems to work for most people to see the bios but I never get to windows.

- hook up hdmi and dp
- open nvidia control panel and set DP connection as the primary display
- reboot
- open nvidia control panel and disable hdmi input
- reboot and problem should be solved

I thought it worked when I saw bios but never made it to windows. Might be worth a try if you haven't done it already.

 

[jonathanrk]

I discovered that the issue was actually with my P2415q. It seems to have extremely flakey DP support which hadn't come up before, such that on any NVIDIA cards I've tried I occasionally need to unplug the monitor from power completely (presumably forcing it to reset some internal state), power it back on, and then connect to the GPU over DP. With that, it mostly behaves as expected. (Oddly, I also see behavior where the monitor's mini-DP port is detected as supporting 3840x2160 @ 60hz, while it's full-sized DP port with a different cable is detected as peaking at 2560x1440 @ 60hz—same behavior on a Titan and two different 970s, in Win 8.1, Win 10, and OS X 10.10.3. 4k monitors are still far from prime time, it seems.)

 

[hunter72007]

your not the only one i am having the same problem none of the 3 DP work or the cable is messed up i have no way to test it i got it to work once but i think that was just a freak thing because i had the VGA cable plug into the MB VGA port i dont have a DVI I or a DVI to HDMI or VGA adaptor i need a solution or i wasted a bunch of money on a second monitor that i cant even use