1958641 - When I'm signed in to YouTube my CPU usage doubles, when signed out of YouTube the CPU usage is normalised.

Status: RESOLVED WORKSFORME

(Core :: Graphics: WebRender, defect)

Description

[treysantana]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:137.0) Gecko/20100101 Firefox/137.0

Steps to reproduce:

Watched a YouTube video signed in, CPU spikes around 80-110%.

Watched a YouTube video signed out, CPU levels halved or at least much lower than when being signed in.

Actual results:

There's an initial spike when being signed out, but then they shortly level out.

Expected results:

Same CPU usage as being signed out.

Comment 1

[treysantana]

Here's my profiler recording: https://share.firefox.dev/3R4DZA3

Comment 2

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Audio/Video: Playback' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 3

[Karl Tomlinson (:karlt)]

In the second part of the profile, memory usage is a few times larger and about 70% of CPU is spent on Renderer thread graphics operations.

Can you check youtube's "stats for nerds" please to see whether Codecs and Current Res are the same or differ according to whether signed in or out?

Comment 4

[treysantana]

Attachment: YouTube Signed-In.png

This is YouTube Signed-In

Comment 5

[treysantana]

Attachment: YouTube Signed-Out.png

This is YouTube Signed-Out.

Comment 6

[treysantana]

(In reply to Karl Tomlinson (:karlt) from comment #3)

In the second part of the profile, memory usage is a few times larger and about 70% of CPU is spent on Renderer thread graphics operations.

Can you check youtube's "stats for nerds" please to see whether Codecs and Current Res are the same or differ according to whether signed in or out?

I've uploaded two attachments, specified.

Comment 7

[Timothy Nikkel (:tnikkel)]

Is the difference because youtube ambient mode is enabled when you are signed in maybe? You can toggle it under the settings gear icon for the video.

Comment 8

[treysantana]

(In reply to Timothy Nikkel (:tnikkel) from comment #7)

Is the difference because youtube ambient mode is enabled when you are signed in maybe? You can toggle it under the settings gear icon for the video.

Ambient mode is off in both instances. It's so strange... before starting to dig into all this, I was watching videos at 720p w/ the "h264ify" extension to combat temps. During my tests, I tried troubleshooting mode - signed-in and out, same results. Private browsing - signed-in and out, same results. All extensions on and off, in normal browsing mode, same results. In all instances, the CPU usage and temps dropped significantly when sign-out of YouTube.

Comment 9

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:gw, could you have a look please?

For more information, please visit BugBot documentation.

Comment 10

[Glenn Watson [:gw]]

Marking as S2 for now, until we understand better if this is widespread.

Comment 11

[Bob Hood [:bhood]]

Flagging as stalled until we have the available cycles to work the issue more thoroughly. Please remove the keyword when the report is being actively addressed.

Comment 12

[Glenn Watson [:gw]]

The profile shows that you are running with software webrender (GPU acceleration is disabled), which will probably explain the high CPU usage. Could you supply the output of your about:support page? If we can solve why acceleration is disabled that may solve the problem.

Comment 13

[treysantana]

(In reply to Glenn Watson [:gw] from comment #12)

The profile shows that you are running with software webrender (GPU acceleration is disabled), which will probably explain the high CPU usage. Could you supply the output of your about:support page? If we can solve why acceleration is disabled that may solve the problem.

So I tried "Use hardware acceleration when available" first... still reading high CPU usage. However, when I also set "gfx.webrender.all" to true in the about:config section in conjunction with the basic hardware acceleration option mention before, the CPU usage dropped to around 20%. Still higher temps, but this is far more manageable IMO.

It's just so strange that I can have all those things set on their previous parameters, sign-out, and the CPU usage drops all the same as this recent fix.

I had kind of given up using YouTube with Firefox in the meantime, and just defaulted to Safari because it would help my temps around where I prefer them.

Either way, this works enough for me, thank you so much.

Comment 14

[BugBot (nomail) [:suhaib / :marco/ :calixte]]

Since the bug is closed, the stalled keyword is now meaningless.
For more information, please visit BugBot documentation.