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'System theme — auto' does not work and causes CPU usage 100%

  • 2 பதிலளிப்புகள்
  • 1 இந்த பிரச்சனை உள்ளது
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  • Last reply by PasBo

'System theme — auto' does not work and causes CPU usage 100% I noticed this July 1 an increase in CPU usage of up to 100% when viewing videos on YouTube from Mozilla. I removed all my add-ons without improvement. I noticed that this phenomenon did not occur when viewing in 'full screen' but only in a window. By disabling the 'System theme — auto' theme, the problem disappeared. I noticed that this theme was updated to version 1.3 today July 1st. I add that this theme, which is supposed to follow the system theme, does not work correctly under Windows 10 when, as for my system personalized theme have been set. I have ‘title bar and windows borders’ in green option for active windows and in purple for inactive windows. Mozilla displays the 'title bar' in black.

'System theme — auto' does not work and causes CPU usage 100% I noticed this July 1 an increase in CPU usage of up to 100% when viewing videos on YouTube from Mozilla. I removed all my add-ons without improvement. I noticed that this phenomenon did not occur when viewing in 'full screen' but only in a window. By disabling the 'System theme — auto' theme, the problem disappeared. I noticed that this theme was updated to version 1.3 today July 1st. I add that this theme, which is supposed to follow the system theme, does not work correctly under Windows 10 when, as for my system personalized theme have been set. I have ‘title bar and windows borders’ in green option for active windows and in purple for inactive windows. Mozilla displays the 'title bar' in black.
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தீர்வு தேர்ந்தெடுக்கப்பட்டது

Thank you for your suggestions. 1. Desactived extensions I had already done this previously without any improvement. I tried again today, with no more results. In windowed mode, viewing Youtube increases CPU usage to the maximum (70% for firefox). and much more than viewing Youtube in full screen because then the CPU is used at 61% (51% for firefox) 2. Disabled hardware acceleration By removing the hardware acceleration, the CPU is no longer used at 100% . Playing a video on Youtube in a window, I notice 77% CPU use (61% by Firefox) . In full screen, the CPU usage in comparison drops to 52% (40% for Firefox). 3. userChrome.css/userContent.cs I don't use a custom user interface at all - no modification or use of userChrome.css Removing hardware acceleration solves part of the problem. But conceptually, I had a hard time understanding why - in short - a fullscreen video consumes less CPU than a windowed video. As a result, I investigated further by reviewing Youtube's settings. In the Playback and Performance/Browsing options, I disabled 'Play videos by hovering over them on the home and search pages' and I notice that the CPU usage for windowed videos became equivalent to the usage needed to play fullscreen videos. I add a spicy observation. This deactivation does not do what it is supposed to do! Thumbnails always animate when the mouse pointer passes over them. In conclusion, here is a problem solved by accident and a mystery that remains. One thing seems certain; the problem does not come from Firefox but from Youtube itself.

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Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or if userChrome.css/userContent.css is causing the problem.

  • switch to the Default System theme: "3-bar" menu button or Tools -> Add-ons -> Themes
  • do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

தீர்வு தேர்ந்தெடுக்கப்பட்டது

Thank you for your suggestions. 1. Desactived extensions I had already done this previously without any improvement. I tried again today, with no more results. In windowed mode, viewing Youtube increases CPU usage to the maximum (70% for firefox). and much more than viewing Youtube in full screen because then the CPU is used at 61% (51% for firefox) 2. Disabled hardware acceleration By removing the hardware acceleration, the CPU is no longer used at 100% . Playing a video on Youtube in a window, I notice 77% CPU use (61% by Firefox) . In full screen, the CPU usage in comparison drops to 52% (40% for Firefox). 3. userChrome.css/userContent.cs I don't use a custom user interface at all - no modification or use of userChrome.css Removing hardware acceleration solves part of the problem. But conceptually, I had a hard time understanding why - in short - a fullscreen video consumes less CPU than a windowed video. As a result, I investigated further by reviewing Youtube's settings. In the Playback and Performance/Browsing options, I disabled 'Play videos by hovering over them on the home and search pages' and I notice that the CPU usage for windowed videos became equivalent to the usage needed to play fullscreen videos. I add a spicy observation. This deactivation does not do what it is supposed to do! Thumbnails always animate when the mouse pointer passes over them. In conclusion, here is a problem solved by accident and a mystery that remains. One thing seems certain; the problem does not come from Firefox but from Youtube itself.