SteamVR
Stal2k 2020 年 11 月 25 日 下午 12:56
SteamVR + Windows GPU Scheduling causing VR Fail in some apps like DCS
ISSUE
With Windows GPU Scheduling enabled, SteamVR can fail in certain applications, DCS is the easiest one to reproduce this in. My speculation is that poor VRAM management can exacerbate this issue.


OS / Software
Windows 10, Build 19042 (though this has been ongoing for months)
SteamVR both stable and beta versions were tested

Attachments:
Forum post containing 7 video examples with realtime logging[forums.eagle.ru]
Direct link to log package including dxdiag, application logs, and SteamVR[forums.eagle.ru]
Please note, for the forum link you will likely have to scroll to post #99 as their forum software lazy loading is screwing up direct post links. The numbers are in the upper right corner of the individual post boxes.
Single YouTube screencap of the issue happening extremely fast. Also, this is Scenario 3 from the above referenced 'pack' of logs/caps.

STEPS

These are App-specific, using common sense you could generalize them further but the mission file has to be of at least medium complexity to reliably force the issue quickly.

1) In Windows, enable the GPU scheduling feature (System --> Graphics Settings)
2) Fire up DCS, again this happens in other places but DCS was the easiest to force it
3) You can use the supplied mission in the archive or just anything with medium complexity. Using maps/modules that are heavy on the VRAM make it occur much quicker. Examples being Persian Gulf or Syria for maps, the F-148/14 for modules
4) Cycling the views via F2 or the top down map F10 will help cause the crash quickly, our testing method was to effectively load into a plane, press F2 a few times, then press F10 a few times, switch to a different plane and repeat. As DCS started to chug, eventually the HMD will go black and SteamVR will fail.

RESULTS
SteamVR will fail, HMD will black out as if it's been unplugged. You can either reference the very first post of the thread linked for additional references or take my word for it that it's not just the Valve/lighthouse devices, but any HMD running through Steam. Anecdotally it does seem more frequent with the lighthouse based HMDs.

EXPECTED
For the HMD to not crash, SteamVR be able to gracefully handle a loaded down GPU (VRAM/Usage) while a stock windows feature is enabled. Obviously, as a workaround turning off the GPU scheduling feature mitigates the crash but recently it's also proven to have a very positive impact on performance for some newer titles, as well as DCS in general. Without this feature enabled VR performance as a whole is diminished in some capacity, as the Windows Desktop Manager process will eat up a lot of GPU without it enabled.

Admittedly some of this may be up to the individual applications, but in this specific instance using DCS, it does not actually crash - just SteamVR. The app will continue to run and you can even somewhat use it. It's easy to play the blame game with Eagle Dynamics or Microsoft but I'm submitting this with the intent that those responsible for the SteamVR application will want to mitigate the impact of poor/legacy design crashing SteamVR.
发帖日期: 2020 年 11 月 25 日 下午 12:56
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