I have to say, firefox on ubuntu's performance is attrocious. Very quickly it gets into 100% cpu use (thank god I have multiple cores) and hundreds of megs of ram. Even closing tabs does not help the issue (unless google.com uses supreme amounts of javascript).
On the same machine chromium browser runs lightning smooth. I tried swiftfox, nothing useful there. Is this a common problem? Only recent (past 3.6) versions have even been able to scroll rather smoothly vs choppy performance when using the scroll bar on pages. The performance is getting close to running firefox on a windows xp virtual box vm.
Edit:
OS:
Kubuntu 9.10. Installed Gnome packages for Ubuntu and use those. Upgraded to 10.04.
64bit
Nvidia Proprietary Video Drivers using the Restricted Driver tool.
Hardware:
Core 2 Quad
4gb DDR2 667 ram
7200rpm hdd
Nvidia GeForce 8800
Also note for everyone responding:
The default settings work damn well in windows on the same machine. The performance in Linux is what sucks.
Best Answer
I can't replicate the issues you're detailing - this seems very odd to me (and I'm speaking on the level of testing on multiple machines. This likely may be something particular with your setup.
Here are a few things that can contribute to poorer performance on a machine:
I would search for people exhibiting similar issues with Firefox on setups similar to yours ( You didn't provide anything so I can't really help you further ) but it may be a configuration, compilation issue.