1317034 - With "layers.gpu-process.dev.enabled;true" my GPU slowly rises in temperature

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[Ciprian Muresan [:cmuresan], Ecosystem QA]

User Agent 	Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:52.0) Gecko/20100101 Firefox/52.0
Build ID 	20161107030203

[Affected versions]:
- Nightly 52.0a1

[Affected Platforms]:
- Windows 10x64

[Prerequisites]:
- layers.gpu-process.dev.enabled is set to true
- GPU temperature monitor program(MSI afterburner, GPU Tweak, HW monitor) is installed
- at least 10 tabs opened with various content

[Steps to reproduce]:
1. Open the GPU temperature monitor while the browser is closed and note the GPU temperature.
2. Open the browser with the profile from prerequisites.
3. Go grab a cup of coffee/tea or work on something else for a while.
4. Note the GPU temperature from the GPU monitor after half an hour has passed.

[Expected result]:
GPU temperature is mostly the same as the value in Step 1 (+- 1 degree)

[Actual result]:
GPU temperature has risen by ~10 degrees.

[Notes]:
- I usually have my PC on during the night, for a few days I woke up to see my GPU at 50+ degrees in idle; with the pref off, GPU temp goes back to 30 degrees in idle.
- I have Nvidia GTX 970 video card.
- Turning off layers.gpu-process.dev.enabled "fixes" the issue.

Comment 1

[David Anderson [:dvander] - inactive, e-mail if emergency]

Barring something extremely weird, the most probable cause would be that somehow the GPU process is not idling when it should be. We can check whether we're compositing extra frames as a first step.

Could you set "layers.acceleration.draw-fps" to true in about:config?

If we're failing to idle in the compositor, the first number should be consistently higher with the GPU process enabled than without.

Comment 2

[Ciprian Muresan [:cmuresan], Ecosystem QA]

I no longer believe that the issue I described was because of layers.gpu-process.dev.enabled;true due to the following:
- I was able to reproduce on a Nightly build which didn't have the pref.
- I was able to reproduce on Firefox release 49 (at the time) which doesn't have the pref.
- the issue is no longer reproducible on the last two Nightlies.

The results I got could have been caused by the tabs I had open at the time.
I'll resolve as Worksforme and remove the block on Bug 1307578. I'll keep an eye out in any case.