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Extremely high CPU usage while playing video (youtube)

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Firefox become hopelessly show to play even 480p videos from youtube 90% CPU usage while playing 720p video from youtube freezing randomly. (same issue on other notebooks, so I have a strong feeling it is not a hardware/notebook related issue) Hardware:

  • CPU: i7-6500U
  • RAM: 8GB / DDR3
  • Video: Intel HD graphics
  • Memory usage never runs above 60%

OS: doesn't matter, experiencing same issue on windows 7/10 and linux.

to compare, same video 1080p/60Hz played with:

  • brave/chromium ~30..35% cpu
  • mpv playing same video directly from youtube ~ 19..25% cpu
  • Firefox - constantly freezing, youtube autmatically switching from 1080p to 720p, then to 480p, playing 480p @ 60..90% cpu usage

I have tried everything from this forum and from others - nothing helped.

And finally, last nail in a coffin - even my very old notebook Core2duo with 2GB ram playing 720p videos with brave browser without issues while firefox struggling to play 480p, constantly freezing and making notebook fan run like crazy.

Firefox is literally forcing me to use other browser.

Firefox become hopelessly show to play even 480p videos from youtube 90% CPU usage while playing 720p video from youtube freezing randomly. (same issue on other notebooks, so I have a strong feeling it is not a hardware/notebook related issue) Hardware: * CPU: i7-6500U * RAM: 8GB / DDR3 * Video: Intel HD graphics * Memory usage never runs above 60% OS: doesn't matter, experiencing same issue on windows 7/10 and linux. to compare, same video 1080p/60Hz played with: * brave/chromium ~30..35% cpu * mpv playing same video directly from youtube ~ 19..25% cpu * Firefox - constantly freezing, youtube autmatically switching from 1080p to 720p, then to 480p, playing 480p @ 60..90% cpu usage I have tried everything from this forum and from others - nothing helped. And finally, last nail in a coffin - even my very old notebook Core2duo with 2GB ram playing 720p videos with brave browser without issues while firefox struggling to play 480p, constantly freezing and making notebook fan run like crazy. Firefox is literally forcing me to use other browser.

All Replies (5)

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Start Firefox using Troubleshoot(Safe) Mode {web link}

A small dialog should appear. Click Start In Troubleshoot(Safe) Mode (not Refresh). Is the problem still there?


https://support.mozilla.org/kb/Firefox+is+already+running+but+is+not+responding

https://support.mozilla.org/en-US/kb/firefox-slow-how-make-it-faster

https://support.mozilla.org/en-US/kb/firefox-uses-too-many-cpu-resources-how-fix

https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-ram

https://support.mozilla.org/en-US/kb/firefox-hangs-or-not-responding

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FredMcD, Thanks for reply!

I told already, I have tried everything, including putting spare ssd into notebook, installing fresh OS, updating to latest OS/Browser (actually stock, old firefox, preinstalled in linux mint works much, much faster, but still 2x cpu requirements compared to brave), then running browser / youtube - 1080p/60hz videos and .... 70-80%CPU while playing. 2k,4k - you cannot even dream about it ... Hole notebook freezes... Done this with notebooks with i7-6Gen cpu and i5-4Gen. Both PC-s are HP probooks, with only Intel HD graphics on board.

All other browsers works just fine.

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I called for more help.

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Are your ffmpegs and libav up to date? I'm on a rolling version of openSUSE so the version in your OS may be different. What OS and desktop are running?

Operating System: openSUSE Tumbleweed 20210723 KDE Plasma Version: 5.22.3 KDE Frameworks Version: 5.84.0 Qt Version: 5.15.2 Kernel Version: 5.13.2-1-default (64-bit) Graphics Platform: X11 Processors: 8 × Intel® Core™ i7-4810MQ CPU @ 2.80GHz Memory: 31.0 GiB of RAM Graphics Processor: Mesa DRI Intel® HD Graphics 4600

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I see a spike in usage when running 4K. see screenshots