I tend to have a couple dozen tabs (in multiple instances) of Firefox running at any given time. But I've noticed (at least in Windows) that sometimes the program will start to saturate the CPU, and take forever to reload a site, or even to switch from one tab to another. When I shut down the program, the CPU usage goes from a hundred percent to a few percent. But when I reload it, with all previous tabs restored, it shoots back up to a hundred. I suspect that it's just one of the tabs that's causing the problem, but the Windows task manager can't provide any insight, because it's happening inside the application.
It would be really nice if the Firefox folks would put in a diagnostic tool that would tell which open tab, or tabs, was causing the problem, so that one could just close that one without having to kill the whole program. It's really made it almost unusable until I can figure out which one it is. Or just start over, but keeping them open is my way of bookmarking items for later blogging.
I haven't yet experienced this problem with 3.0 (Windows). With earlier versions this kind of behavior was usually caused by a poorly written script on one of the open tabs, and I could usually track down the cause by process of elimination.
3.0 is much better than previous Firefox versions, but still seems to suck up RAM to an excessive degree if you leave it running long enough.
I use NoScript to block nuisance scripts, and to block scripts on sites I don't trust. I think it helps to prevent problems of the type you discuss, though the benefit may be marginal.
Diagnostics for the individual tabs would help.
I'm using 3.0.1. I finally found the problem, or at least got rid of it. I didn't identify which tab it was, but I did seem to close it, because things are much better now. It's annoying to have to do it by trial and error, though. It seems to me that if you're going to allow multiple tabs, you ought to provide some way of seeing what the individual pages are doing to the browser.
Rand,
I've experienced the same problem with 3.01 (Windows XP env.). In my case, one of the blogs I read (on Blogger) was the major memory hog, but it wasn't the only one to create problems. I was particularly annoyed because while I was dealing with this issue, I kept reading about how the FF memory hole had been plugged.
Mozilla people are aware, but not approaching it right, I believe. Their reply is to introduce the API called nsObserverService, and a matching extension called Plugin Watcher. This still does not do anything for runaway scripts and does not identify the tab that causes trouble. I think it'll take time for them to wisen up and write the relevant code.
Hmmmm.
I've had the same problem. In my case it was a Flash advertisement by HP on a UK website. The silly thing only had a bunch of tree branches swaying in the wind but evidently it was calculating this action rather than following a set script.
Pegged my CPU to 100% every bloody time I ran across it, which was almost everywhere.
Now I run Firefox without Flash loaded and, if I need to use Flash, I run IE in a tab.
Correction: I'm using 3.0.1 too.
I've had the same problem. In my case it was a Flash advertisement by HP on a UK website. The silly thing only had a bunch of tree branches swaying in the wind but evidently it was calculating this action rather than following a set script.
Infinite loop. I've had the same problem many times. Blocking Flash helps. Firefox should have a user-configurable option to automatically shut down any script that uses more than X% of processor capacity.
As with blogging software, browser functionality lags far behind the demands imposed by use in the real world.
Like the first Commenter said, install the NoScript add-on to automatically disable scripts and flash in webpages. It has a "remember" feature so you don't have to allow pages you visit regularly. This way, you can enable the scripts when you get to the page, but all text content will load. Often I find I don't need to look at any of the flash stuff anyhow since they are usually ads. Embedded videos just require you to click the blank area to allow. Very useful tool and a great block for all that unnecessary clutter on webpages.
Rand
It is my experience with this that one of the tabs is running a video or other type of repetitive Javascript and it brings the entire machine to its knees.
Nobody mentioned it yet so I will. the tech in me always keep it simple stupid. Del your temp internet cache. You never know if you are pulling a script out of cache that could be butting heads with new content on a page that is regularly visited. Personally, I like to leave my scripts running. I use Adblock +plus add-in to close down overly annoying sections of a page.
One can also see if it is a add-in or a corrupt profile setting that is causing the issue. Go to Start_Run and type firefox -P or -profilemanager. Create a new profile and test to see if you experience same problem without any add-ins or browser configuration changes made.