Firefox 3.0 renders pages slowly at 100% CPU and is unresponsive as it does so

[kripken]

Binary package hint: firefox-3.0

(This is a new issue for me as of a few days ago. Perhaps something to do with recent updates.)

Comparing FF2 to FF3 on this computer - the only difference is FF2 vs FF3 - I find that FF3 is very unresponsive. Loading a new page causes 100% CPU usage for around a second or so, during which time Firefox is completely unresponsive (I can't even switch to another tab as I wait). This is particularly noticeable when several pages are loaded at once (e.g., when I start Firefox, or when I middleclick several pages that I want to read later) - the 100% CPU/unresponsive time can last for 5 seconds or more.

This appears to occur more obviously with pages with more images, but otherwise, no idea why it is worse in some cases and less in others.

I am using the NVidia binary driver. However, as I mentioned, FF2 is responsive and fast on the same computer, so not sure if this is relevant or not.

[plun (plun)]

Just confirming this and for me its just when FF3 starts. Non-responsive for about 15 seconds
loading 3 tabs. No difference between Ubuntu version and nightly build.

Adblock Plus installed as addon

Mozilla "bug", startup investigation
https://bugzilla.mozilla.org/show_bug.cgi?id=406810

[AJ (akertis)]

I can also confirm this bug with firefox 3 and have the same problem with the latest beta 3. Since hardy took firefox 2.0 out of the repo now it is very hard to have a stable browser.

[Pēteris Krišjānis (pecisk-gmail)]

I can confirm this. When pages are opened very fast one after another (within 10 secs some five or six), Firefox freezes for some 10 - 20 secs and are veeeeeeery slow. After closing several of this pages, it get back to normal. I suspect Flash plugin too. It have caused problems with FF2, but not at such scale.

[Daniele Dellafiore (ildella)]

just installed gutsy + hardy update yesterday on a brand new dell xps 1530 with nvidia 8600.

ff3 tab switch is really slow, much more slower than on my 3 years old desktop.

i use ff3 on the desktop that has gutsy also because ff2 tab switch was really slow. here, on the xps, ff3 tab switch is even slower, it takes more than a second to switch.