GPU Lockups

I anyone else having GPU freezes in DCS? I have four monitors, and for the past few months I've been getting random GPU lockups in DCS. PC is still running, I can connect to it via Remote Desktop, it's only the graphics that crashed. Temps are fine (upper 60s), GPU stress test works fine. It's only in DCS. Event Viewer tells me that DWM.exe crashed with an Unknown faulted module.

Re-installed drivers, did the driver wipe and all that. Tried all of the common stuff (virus scans, disk scans, etc). Still happens, and only during DCS. I have occasion to switch DCS to a single-screen config occasionally and it has not locked up in that config. Only seems to happen when using multi monitor configs, although it may be coincidence because it doesn't always lock up in multi monitor either.

Intel I9-9900K, 32GB RAM, RTX 2070 Super, Gigabyte Z390 Aorus Ultra MB, VPC Warbird base/WH stick and throttle.

dwm.exe is the Windows 10 window manager. This is the process that draws the windows and decorations like the title bars, handles, open/close/minimize buttons on the screen.

This makes me think that the system is having an issue managing the four different screens and is crashing due to some kind of out of bounds exception.

Are there any hints/references to screen issues in the dcs.log file?

My "gut" says to play around with the LAlt-Enter switch to move between full screen and windowed mode. Even when the screen looks full screen in DCS it can be windowed. DCS weirdness. If it crashes one way, reboot and when entering DCS hit LAlt-Enter and see if it still crashes at some point.

Also, for shiggles you could try reducing the number of screens temporarily and/or changing screens to "mainstream" resolutions like 720p or 1080p if they aren't like that already.

There's likely guides to multi-screen setups with DCS - maybe do some some further searching in this forum section and in the Input/Output forum section.

HTH

Some good tips there.... thanks!

My "gut" says to play around with the LAlt-Enter switch to move between full screen and windowed mode. Even when the screen looks full screen in DCS it can be windowed. DCS weirdness. If it crashes one way, reboot and when entering DCS hit LAlt-Enter and see if it still crashes at some point.

Yep +1

For some reason I have to do this everytime I run DCS (LAlt+Enter once, when entering the main screen or with map already loaded).

It's been like that for years, no matter if Nvidia or AMD GPU, if with Fullscreen option ticked or not. Otherwise it stutters quite a bit.

After that, it's smooth sailing. :thumbup:

LALT + Enter doesn’t really work for multi monitor users. It puts DCS onto your main display, squeezing and distorting it however it has to in order to do that. For example, if I have two monitors and my main viewport resolution is set to, say, 3840 x 1080, It’ll squeeze my 3840-wide main viewport onto my 1920-wide main Windows display with all the distortion that comes with it.

Here is an example, the first image is my DCS on two monitors, 2560 x 2520. The bottom monitor is behind some MFDs and a Helios overlay. So you're seeing two monitors there. The second image is after LALT-ENTER and it's all squeezed onto my 2560 x 1440 main monitor.

Right - makes sense. If you hit LAlt-Enter again does it revert to the way it should be or does it get stuck all on one screen?

1440p is kind of a "non-standard" resolution - at least when dinosaurs roamed the earth and originally wrote the Windows GDI.

As an experiment, try setting the screens to 1080p and see if you can get the window manager to crash by beating on it heavily with a bunch of DCS missions.

Far from ideal but might lead to other clues.

Another idea: HDMI might be the one with the issue. I wouldn't be surprised if you switched to three displays all on DisplayPort it was rock solid. HDMI and DP are handled differently at both the hardware and software level - might be some kind of a mismatch that is making it bork. You aren't using any adapters for DP <-> DVI or HDMI, right? Sometimes this makes a difference (Hackintosh'ing is a PITA this way).

Are you running Windows 10 rev 2004? If you are not then consider upgrading. If you are on 2004 try switching HAGS on/off to see if it makes a difference (this one is a shot in the dark but maybe it re-plumbs the software<>hardware pipeline and makes a difference to catching edge cases that affect dwm.exe).

Interesting problem.

Right - makes sense. If you hit LAlt-Enter again does it revert to the way it should be or does it get stuck all on one screen?

It reverts the way it should (thank goodness).

As an experiment, try setting the screens to 1080p and see if you can get the window manager to crash by beating on it heavily with a bunch of DCS missions.

Yeah, that was one of the things I was going to try next. I have a 1080 touch monitor on the HDMI and three 1440p's on the three DP ports. I figured the mix of resolutions could be one of the issues.

Another idea: HDMI might be the one with the issue. I wouldn't be surprised if you switched to three displays all on DisplayPort it was rock solid. HDMI and DP are handled differently at both the hardware and software level - might be some kind of a mismatch that is making it bork. You aren't using any adapters for DP <-> DVI or HDMI, right? Sometimes this makes a difference (Hackintosh'ing is a PITA this way).

No adapters, the 1080 touch screen is HDMI straight into the 2070S.

I didn't always have the touch screen. I previously had three Lilliput 7" USB displays. When this whole problem started, I switched out the three USB MFDs and replaced them with the 24" touchscreen thinking that might help with the issue. So I don't think the HDMI touchscreen is the issue.

Are you running Windows 10 rev 2004? If you are not then consider upgrading. If you are on 2004 try switching HAGS on/off to see if it makes a difference (this one is a shot in the dark but maybe it re-plumbs the software<>hardware pipeline and makes a difference to catching edge cases that affect dwm.exe).

I'm running Windows 10 Pro, not sure which version. I recently upgraded to the Pro to get Remote Desktop which I was going to use for troubleshooting (log in remotely during an event to try and get some clues). I'll check the version.

Interesting indeed... I strangely enjoy the troubleshooting aspect of a tough problem. I just wish I didn't crash out of DCS at the most inopportune times.

The three 1440p DP screens are direct connected DP <-> DP at both ends, correct?

It sounds like the HDMI screen addition is not the problem.

Were the Lilliput USB MFDs a recent addition? Did this issue coincide with adding them? If you are not using the USB MFDs any more did you ensure that the driver (if any) is not loaded? Still hanging around? <shot in the dark>

Also, disable remote desktop if it is turned on. Come to think of it - RDP will probably go totally stupid trying to deal with four screens (and buffer/present them to a remote connection even if not connected) and might cause the window manager to crash. I've seen similar issues on really old versions of XDMCP<->VNC under UNIX/Linux. I don't expect that the Windows 10 window manager is structured like X-Window but then again IIRC Windows NT was a copy/rip of VMS architecturally so... who knows. Another shot in the dark.

FWIW, I have Windows Pro on my DCS boxes and haven't had this problem but I'm typically only using one screen and when I had two screens I'd disable the second one to keep frame rates up.

The three 1440p DP screens are direct connected DP <-> DP at both ends, correct?

Correct

Were the Lilliput USB MFDs a recent addition? Did this issue coincide with adding them? If you are not using the USB MFDs any more did you ensure that the driver (if any) is not loaded? Still hanging around? <shot in the dark>

They weren't recent. I had them for a couple years, my current problem started last December and I removed the Lilliputs in May. I did delete the drivers when I removed them.

Also, disable remote desktop if it is turned on. Come to think of it - RDP will probably go totally stupid trying to deal with four screens (and buffer/present them to a remote connection even if not connected) and might cause the window manager to crash. I've seen similar issues on really old versions of XDMCP<->VNC under UNIX/Linux. I don't expect that the Windows 10 window manager is structured like X-Window but then again IIRC Windows NT was a copy/rip of VMS architecturally so... who knows. Another shot in the dark.

I'm not actually connected via remote desktop all the time, I only connect after the GPU has crashed so that I can look to see if there are any errors on the screen.