Within the last couple of weeks, my CPU usage has been jumping from 35% to 60% while Firefox was running. When I closed it, the usage dropped to under 4%. I was running FF v3.6.2 and upgraded to 3.6.10 with no change to CPU usage. I haven't added any more extensions. Any idea why this is happening?
Firefox has a safe mode. Have you tried this? If safe mode runs with no issues, it is likely one of your extensions.
Firefox generally uses more resources as compared to other browsers. As said by the above member, try firefox in safe mode. To enter safe mode type: firefox -safe-mode in the Run box.
About a year ago I was having the same problem. I solved it that time by installing the FlashBlock extension. I have not installed any extensions for over a couple of months, so this is probably not due to an extension. I even noticed that when I click on a tab, it takes a 2 or 3 seconds before the tab opens.
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