P2715Q, 4K 60Hz always messes up my windows layout?

Hello,

i have just acquired a Dell P2715Q and am using it with a Dell U2713HM on a new Mac Pro machine using Bootcamp and Windows 8.1 Pro 64bit. The video card is dual AMD D700 with drivers for AMD 7900 series for the simple reason of having better API support. I use DP to miniDP cables, one of them is the one that came with the P2715Q. The problem:

Every time the computer goes to sleep or displays are turned off i get the DisplayPort Link Failure error =

All the windows layout get messed up, moving everything to the main display. I have to say that before this change i had 2 U2713HM and all worked just fine. I am looking for any help that could help solve this issue.

Thanks in advance

Yes that is correct, so you're saying this would be a Windows issue ? I suppose is that's so everyone who has such a monitor would be here complaining about that.

I can imagine that windows would take fullHD as a safe resolution these days, but if that is so this should also happen with any other monitors above that safe resolution.

I have another 2 U2713HM monitors from Dell which i use as dual setup and they never caused this problem. Both set to higher than FullHD.

When Windows wakes back up, some display drivers will initializes the resolution to a safe setting - like 1920x1080 - before changing the resolution to the native 4k. When the first safe resolution kicks in, Windows rearranges your open windows to fit in the new, lower resolution; it does not - and isn't expected to - reposition them when the native resolution is restored.  You may be able to manually reproduce the problem like so:

1. Set the resolution to 4k

2. Arrange your open windows to the right edge of the screen

3. Use Windows Display properties to change the resolution to 1920x1080

4. Now immediately cancel the change to return to 4k - chances are your right-aligned windows are no longer right-aligned

Yes that is correct, so you're saying this would be a Windows issue ? I suppose if that's so everyone who has such a monitor would be here complaining about that.

I can imagine that windows would take fullHD as a safe resolution these days, but if that is so this should also happen with any other monitors above that safe resolution.

I have another 2 U2713HM monitors from Dell which i use as dual setup and they never caused this problem. Both set to higher than FullHD.

Its a display driver, not Windows issue, and it is largely specific to 4k monitors and certain display drivers. Some display drivers and monitors have this behavior and some don't; I suppose in technical terms it could be an issue with how long it takes a specific monitor to wake up and relay its EDID (which holds the monitor's native resolution) to the display driver, and/or how long the display driver waits for the EDID to arrive before initializing the display. Does that make sense?

Anyway: if you use Dell Display Manager and are comfortable editing the registry you may be able to sidestep the problem by adding a "RestoreWindowLayout" value to HKCU\Software\EnTech\DDM and setting it to 1 (dword). To get the latest release, hold down the Shift key while right-clicking on the DDM system tray icon and select "Check for updates" from the popup menu.

Would be nice to hear from Dell on which videocards/drivers they actually have got it working fine.

This has been told to Dell and they never said anything like that, probably do not want to cut down of the sales.

I have already tried the registry RestoreWindowLayout value and it didn't work for me either. I have the latest DDM installed and also got the latest drivers for this monitor installed. javascript:void(0);

I believe i've tried all the tips and tricks and they all failed in my case. Not sure about other people.

Would be nice to hear from Dell on which videocards/drivers they actually have got it working fine.

This has been told to Dell and they never said anything like that, probably do not want to cut down of the sales.

I have already tried the registry RestoreWindowLayout value and it didn't work for me either. I have the latest DDM installed and also got the latest drivers for this monitor installed.

I believe i've tried all the tips and tricks and they all failed in my case. Not sure about other people.

This sounds like an issue with the video card or video card driver and the P2715Q maximum 3840x2160 60Hz. The U2713HM's maxed to 2560x1440 60Hz so you did not see the issue.

On the P2715Q:
* Change to 2560x1440 60Hz
* Test sleep/wake
* Change to 3840x2160 30Hz (MST Primary)
* Test sleep/wake

What are the results?

I have tested both.

2560x1440 @60hz fails the test. Same problem.

on the other hand, 3840x2160 @30hz seems to work. I've tested sleep/wake twice now and so far it seems to keep things as before.

3840x2160 60Hz = Two 1920x1080 60Hz "tiles" stitched together. So test 1920x1080 60Hz.

I already got 2 monitor exchanges. I didn't run all these tests with them but i had the same issue.

Are you guys doing anything about this? Or are we just supposed to deal with it ? I kindof feel like i don't have what i paid for.

You could get a monitor exchange, but the replacement will have the same issue. Read this.

Chris, do you know who to contact about such an issue?

That document was written by the Displays Team, so no, there is not another contact. I have not received any further news. Your only option is to escalate and press for a refund which would take manager approval.