As far as I can tell, I’m not doing anything that would cause it to suddenly use 90%+ CPU (from 8-12%) every 30 seconds or so. My CPU usage graph looks like the goddamn stock market, and I’m really getting tired of it.
Might Flashblock help? I’ve read someone who said that it CAUSED high CPU usage for him. Someone else suggested raising browser.sessionstore.interval in about.config.
I just want it to stop! HELP!
Stop what:confused:
Subject line: How the HELL do I stop Firefox’s frequent CPU spikes?
I’ve disabled one of my less frequently used add-ons to see if that helps. I’ve also set about:config’s default on animated images to not have them run. It seems to take about a week to get really bad — restarting the browser seems to help (and also frees up a ton of inactive memory).
We’ll see what happens.
Flash has nearly ruined Firefox. Sometimes I can’t even switch between tabs. Even closing a tab can take 45 seconds. Using task manager to kill the plug in container helps a lot.
I constantly get the warning box that a Flash Script isn’t responding. Usually my cpu and memory usage are way high too.
(Assuming you’re on Windows): It’s the current version of Flash (11.x) that’s causing problems. Adobe hasn’t given Mozilla Foundation info on the programming hooks needed to integrate with the new DirectX drawing methods Flash 11.x uses. If you downgrade to Flash 10.x, most of the CPU usage problems should disappear. That version is still using the older Windows GDI drawing calls.
(Bold added.)
I’d like to try this too. What is this setting of which you speak?
My preference is always to have my browser configured to be as crippled as possible, with any fancy-schmancy features enabled only when I want them. (I’ve mentioned umpteen times that I keep JavaScript disabled.) (That’s also why I continue using a really old Firefox version. My impression is that every newer release of just about everything generally just gets worse.)
Use Chrome.
While I personally don’t think there’s anything really wrong with Chrome, this is just silly. There’s no reason to change browsers just because of one minor annoyance that can be easily fixed.
That’s like telling someone to trade in their car for a different model simply because they got a flat tire. Yes your new car won’t have a flat tire, but that’s not really the appropriate level of response required.
I used to be a heavy Firefox user. Firefox has never successfully cleared up their CPU issues, even a cursory glance at the Mozilla support forums shows how pervasive an issue it has been. I’ve tried every “fix” on the books, and ultimately mikews99’s suggestion was the only thing that helped, somewhat. If I have to downgrade a browser just to get it to play nice, that’s a deal-breaker in my book. And IMO those CPU spikes were far more than a minor annoyance. So my advice remains the same. Ditch Firefox, use Chrome.
Same here. I loved Firefox for years, but the CPU thing became untenable. The only thing that worked was a switch to Chrome.
You might check your Firefox profile folder to see if you’ve got a bunch of saved sessions built up. They’ll be files with names like sessionstore.js. I had a problem at one point with Firefox saving sessions and not removing the old ones, and it caused a CPU spike every time it saved the current session. You could also try setting browser.sessionstore.interval in about:config to a really big number to see if the spikes become less frequent; that could help you determine if the problem is related to storing the session.
The setting in question is “image.animation_mode”. Set it to “none.”
I did a search in OSX (my OS) for that file name, and it came up with nothing. I’ll look in the profile folder, though. I’m also going to try the browser.sessionstore.interval thing sometime. If Firefox does indeed crash or something (and it usually doesn’t), I really don’t need all my tabs up-to-the-second.
I’m not on Windows, obviously (now), so sadly (?), the downgrade suggestion won’t work. But someone out there does claim that disabling and reenabling the Flash plugin seems to have an effect for some reason.
Speaking of profiles, two questions about them:
My current Firefox profile is quite old, migrated from quite a while ago, IIRC. Could that have something to do with it? Anything I can do about it while still keeping my prefs?
If (IF) I do switch to Chrome, will I be able to bring over my stuff? Do they have something like Adblock and Noscript (either built in or as an addition)?
Thanks!
Googling suggests that it may be sessionstore.bak in OSX. I don’t have an OSX installation to check it on.
The Chrome setup I’m using right now has Adblock and Flashblock (among other extensions), and I’m nearly certain I’ve seen extensions available for script-blocking purposes.
I gave up on Firefox quite some time ago when it got hopelessly slow, bogdown-prone, and crash-prone. Maybe these problems have been fixed, but I’m content enough with Chrome that I don’t feel any great need to switch back.
I agree, too. I’ve been on Firefox for years and I just switched to Chrome this year. The CPU usage aas awful and it made everything run slower. And the longer you run it, the more it took! Chrome works like a charm. Forefox has fucked themselves.
ETA: I installed Adblock within a week. 
nm
i agree that it’s Flash related. if a Flash heavy site hogs the CPU then if i can move away from that site or kill the tab then the CPU usage drops, even with many tabs still open.
Would Flash cause the same problem in Chrome? Because I’m getting spikes there too.
That’s what I thought, too.
..but I disabled, then removed, then nuked Flash Player with the uninstaller from Adobe, and I still got insane CPU and memory usage from Firefox (we’re talking 25% of a an AMD Phenom II 1055T and 3500 MB).
So next, I started trying to determine if it was a problem/conflict with the other plugins/extensions I use in Firefox. I use many, so this was a tedious process.
No luck.
That’s when I installed Chrome.
Maybe.
AdBlock, yes.
…but I haven’t been able to find functional equivalents to:
Bazzacuda Image Saver
Image Toolbar
DownThemAll! (a major loss)
FlashGot (well, I guess Google does own YouTube 
)
NoSquint (I’ve set Chrome to 125%, but it would be nice to have zoom levels for each site)
Tab Mix Plus (finding a specific tab in Chrome when you have 20+ open is ‘difficult’)
I was surprised at how bad Chrome Extensions are in general. Not only are there far fewer than for Firefox, but of the dozens I’ve tried, they tend to be more buggy, less functional and with terrible interfaces.
I’m guessing the interface problem is because of Google restrictions. Extensions seem to be mostly limited to an icon at the top-right and a smallish drop-down box. Maybe the bugs and limited functionality are also because Google is more restrictive in what it allows extensions to do, thereby stifling development?
On the plus side, Chrome is fast like Firefox never was.
You might give Pale Moon a try. It’s based on Firefox and most of the plug-ins work with it. They also offer a portable version if you want to give it a try without installing it. I have no CPU spikes and my memory usage stays low unless I’m pre-loading a ton of videos from Blip. (I’ve tried Chrome a couple times, but always end up annoyed and go back to Pale Moon).