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Firefox 42.0 slamming the CPU

  • 10 replies
  • 3 have this problem
  • 8 views
  • Last reply by TheGhzGuy

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Hello all! It seems recently I have been having some major issues with Firefox. Namely the fact that, when playing video, the CPU usage goes through the roof. What could be causing this and what can I do to fix this? I appreciate any help anyone has to offer.

I also tried this with AdBlock off, same result.

Specs are: Core i5 4200U 4GB RAM 1080p screen Windows 10

Hello all! It seems recently I have been having some major issues with Firefox. Namely the fact that, when playing video, the CPU usage goes through the roof. What could be causing this and what can I do to fix this? I appreciate any help anyone has to offer. I also tried this with AdBlock off, same result. Specs are: Core i5 4200U 4GB RAM 1080p screen Windows 10
Attached screenshots

All Replies (10)

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Hello! Unfortunately none of the things you suggested have helped. As of right now, it's a Youtube and Firefox issue. But that doesn't explain why is used as much CPU as it did, do you have any other ideas?

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You did try Firefox Safe Mode? Any difference?

Many site issues can be caused by corrupt cookies or cache.

  • Clear the Cache and
  • Remove Cookies
    Warning ! ! This will log you out of sites you're logged in to.

Type about:preferences<Enter> in the address bar.

  • Cookies; Select Privacy. Under History, select Firefox will Use Custom Settings. Press the button on the right side called Show Cookies. Use the search bar to look for the site. Note; There may be more than one entry. Remove All of them.
  • Cache; Select Advanced > Network. Across from Cached Web Content, Press Clear Now.

If there is still a problem, Start Firefox in Safe Mode {web link} While you are in safe mode;

Type about:preferences#advanced<Enter> in the address bar.

Under Advanced, Select General. Look for and turn off Use Hardware Acceleration.

Poke around safe web sites. Are there any problems?

Then restart.

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Unfortunately, I still am having issues with CPU usage, after all of that.

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(And yes, I did try it in Safe Mode)

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FredMcD said

Look for and turn off Use Hardware Acceleration.
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Didn't help either.

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I've called the big guys to help you. Good luck.

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FredMcD said

I've called the big guys to help you. Good luck.

I have no idea what that means, but I'll assume that's a good thing! lol. Thank you for helping out!

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I assume you meant "call in the devs"?