You have already tried the usual troubleshooting steps. Is it definitely firefox that is using the CPU, rather than say background operations such as disk indexing, AV scanning or updating.

• see firefox consumes a lot of CPU resources

It is worth turning on the option mentioned in the article to submit data to Firefox. It may not immediately solve your problem, but the real world data is used to monitor Firefox and pick up regressions and otherwise unreported or unoticed problems.

Malware is a possibility that may need ruling out see

• is my firefox problem a result of malware
• /questions/914980#answer-302372

Firefox.exe causes peaks, please see attached screenshot I made after 5 minutes of regular browsing.

This is mainly caused by firefox.exe and not any other process - plugin-container.exe is at 1-5% if there are no flash apps running. Malware can be ruled out, since this happened exactly after the update and I did run a malwarescan with no result.

I am not too sure that result shown above looks wrong. If you have Firefox open, especially with quite a few tabs open then there is likely to be activity.

Firefox does have housekeeping tasks to perform, some of those will create spikes of activity.

John99, The problem is how unresponsive firefox becomes everytime it peaks at 35%. It locks up the browser and sometimes I can even see the window being greyed out just like before an application crashes - rebuilding the tabs after some 3-5 seconds. Even when I close an empty tab there's a noticeable lag which shouldn't be the case. I wouldn't mind the 30% activity if it didn't block my browsing experience.

I created a new profile - the problem is still around.

Imputforms like the youtube comment form and gmail contact data is like typing on a Typewriter.

Does that mean instantaneous !! like on a typewriter, but that your own keyboard skills are not up to typing above 120wpm on the input forms.

It is not really possible to see from here what the problem is, or to easily determine what you are experiencing. How does Firefox compare with IE perhaps attach a screenshot of CPU usage whilst one then the other is open doing similar things on g-mail.

I'm sorry I didn't clarify this: It's slowed down. I can type in a word and it takes 10 seconds for it to actually show up, character for character. I'm not on this machine currently, but I will attach a screenshot of CPU usage when accessing pages with IE.

Attached a statistic of IE CPU usage - it peaked at 39% but is not as unresponsive as FF. I'm having a feeling this is GPU related - will try to update my grapghic device drivers

It would be worth experimenting with turning Hardware Acceleration on and off. If you have HA enabled but it is not working properly it is likely to cause problems. (If you are using FlashPlayer video that has its own controls for setting HA on or off). To turn HA off in ordinary browsing use

• Firefox Button -> Options -> | Advanced | -> | General | -> [] Use Hardware acceleration when available
  • see Advanced panel - Accessibility, browsing, network, updates, and other advanced settings in Firefox
• you may also wish to see if the Graphics drivers will update
  • see Upgrade your graphics drivers to use hardware acceleration and WebGL
• you may also be interested in this article, including a test that you can run
  http://hacks.mozilla.org/2010/09/hardware-acceleration/

It is looking like some of the problems could relate more to the system, than to Firefox.

I will try those on monday, updating the graphics drivers did not help.

Turning off the hardware accelaration when available option did resolve the problem as far as I can tell. Thank you so much for hanging in there.

OK I guess your Notebook does not cope well with hardware acceleration. Notebooks run on batteries and are optimised for low power consumption.

Just as an aside you could notice differences on mains power instead of battery power as some machines may take steps to reduce power consumption when mains is disconnected.

Same behaviour on batteries and mains power. I actually use it as a desktop replacement. The fonts in the browser are bit more edged and not smooth but that's not a problem. Page load times have decreased and it's even faster than on my personal desktop at home - will try to turn it of back home too.