Firefox 29 is very much slower than 28 in Ubuntu 14.04 or OpenSUSE Tumbleweed, but enough fluent in Win7 same computer
I kept the session contains 500+ tabs in Firefox 28. I updated firefox from 28 to 29 in 64bit Ubuntu 14.04/64bit OpenSUSE Tumbleweed/32bit Windows 7 in the same computer (I installed 3 operation systems in it loaded by Grub 2).
But only firefox 29 in Windows 7 is enough fluent. Firefox 29 in Linux are very very much slower than firefox 28. I even can't close tabs, almostly. So I think firefox 29 is not good optimized for Linux.
I tested this in a desktop computer (AMD Althon 5000+, 4G RAM, ATI 3850 512MB VideoCard, and 1TB Seagate HDD), and a laptop computer (i3 2.53GHz, 4G RAM, 128GB SSD).
Opaite Mbohovái (1)
Create a new profile as a test to check if your current profile is causing the problem.
See "Creating a profile":
- https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
- http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues
If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over the problem
There might be extensions and plugins installed by default in a new profile, so check "Firefox/Tools > Add-ons > Extensions & Plugins" in case there are still problems.