Hello,

To solve your problem you can try out these steps. https://support.mozilla.org/en-US/kb/firefox-slow-how-make-it-faster

Hello starhorsepax, if the problem is an add-on then the solution is to disable it !

check IF after you delete in your profile folder the User.js file, the problem exist.

(The user.js file does not exist by default. If you create the file forget it, if not, note that some programs create and write in the User.js file also).

thank you

I believe I did mention that disabling is not an option. I work in web design: these add ons are ones required. In fact I'm working on a Firefox problem child today: the site works in every browser (Chrome, Safari etc) except Firefox. Without the add ons I can't find the problem to fix it.

Regardless of the fact that you need the addons to work if you wish to sort out a Firefox problem it is going to help if you are able to show that Firefox works OK other than with specific addons installed.

If the problem is there without addons it is a Firefox problem, otherwise it may be a problem with an addon.

If it is a Firefox problem, is it with a specific version ?

Although not relating specifically to hangs and CPU use there is a Memory issue with Firefox on a Mac that has been fixed recently in Fx28

• see /questions/981674?page=2#answer-539109
  (Decidedly none intuitive - Memory increases when Windows minimised ! )

Have you tried upgrading to Firefox 28 does that help ?

Another potential workaround is to use multiple profiles and only use the minimal number of installed addons required for the task in hand.

I did try updating and starting in safe mode. In the beginning it worked, but as I went on it did start to suck more and more power. More than the other browsers anyway. can anyone point me at a link on how to do multiple profiles?

We do no actually document using multiple profiles or multiple versions as it is considered unnecessary for ordinary users. It is however very handy with troubleshooting or I imagine in web development where you may wish to check behaviour in different versions or different configurations of a browser. You just need to be slightly careful that you do not lose track of and accidentally delete profiles or content of profile directories. Backing up profiles may be advisable.

• Back up and restore information in Firefox profiles
• http://kb.mozillazine.org/Testing_pre-release_versions#Installing_multiple_versions

I will add more information in a follow up post.

Also note use the -no-remote argument if you are using simultaneous instances of Firefox, but do not use that on the default profile.

If you have problems or need more suggestions please post back. There are other advanced features that may help.

See

• Profile Manager - Create, remove or switch Firefox profiles
  (Probably the easiest method of creating new profiles.)
• http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox
• http://kb.mozillazine.org/Opening_a_new_instance_of_your_Mozilla_application_with_another_profile
• http://kb.mozillazine.org/Testing_pre-release_versions#Installing_multiple_versions

Using multiple profiles is not something we shout about on this forum. It is I think considered too advanced. It does have some dangers in that you may accidentally delete profiles for instance. It is however possible to manually backup profiles, and that may be a good precaution to take. I would also strongly suggest that you follow this good practice (At least until you are proficient enough to manually recreate and modify profiles)

1. Normally use the locations suggested by Firefox
   It is easier and safer
   • Always use an empty folder
     Other contents disappear when the profile is removed
   • Never nest profiles within each other
     As above,delete mother, lose child also
2. Do not rename profiles
   Confusing, profile names and folder names mismatch
3. Do not delete profiles
   Just remove shortcuts if not in use. Delete the wrong one and you lose settings, passwords & bookmarks etc

Uses of multiple profiles include

• Testing, with clean or temporary profiles
• Different users, or different work type within the same OS account. That may include different bookmarks files &/or a different set of addons.
• Running multiple Firefox versions &/or multiple instances of Firefox simultaneously.

There are other methods of creating profiles but the best is probably to use Firefox's built-in profile manager.

Read up some of the articles, and if you want to try anything and are unsure post back.

• Profile Manager - Create, remove or switch Firefox profiles
• Back up and restore information in Firefox profiles
• http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox
• http://kb.mozillazine.org/Testing_pre-release_versions#Installing_multiple_versions
• http://kb.mozillazine.org/Moving_your_profile_folder#Create_a_new_profile_and_migrate_your_old_data
• http://kb.mozillazine.org/Opening_a_new_instance_of_your_Mozilla_application_with_another_profile