No, this is not a Firefox attack, really. I love Firefox, and it truly is my preferred browser. But …
I installed Firefox 3 on Download day, and made sure that it was a clean install. The only plugins I have installed are Greasemonkey and YSlow. It’s a pretty simple and clean install.
And all is good initially. And then gradually my CPU utilization reaches 100% and the system grinds to a halt, and when I look at Windows Vista Task Manager I see that Firefox is using over 60% of my resources! Heck, it’s more than Outlook uses! Is anyone else running into this one?

34 thoughts

  1. From resource usage point of view, Opera has always been better than Firefox. So give latest Opera 9.5 a try. Granted it doesn’t have all the addons that Firefox does, but instead of Greasemonkey you have built in UserJS support and now there are comparable developer tools included to match what Firebug offers, and more. So visit, I bet you’ll like it πŸ™‚

  2. I’m finding the opposite actually. It seems to be using significantly less RAM, even with all my extensions going. And with Firefox 2 having two gmail tabs and google reader open all day would eventually bringing it crashing to it’s knees. Not any more. I’m also finding it tremendously faster when running these web apps.
    I’ve definitely not seen cpu spikes the likes of which you’ve experienced.

  3. I sure haven’t heard any other reports like you describe… I wouldn’t throw in the towel based on what you are experiencing. I use it on WinXP and Kubuntu with zero problems. Then again I don’t use Greasemonkey or YSlow… or Vista!

  4. I’m on 3.0 with Windows Vista Ultimate. I’m using Firebug 1.2.0b3, fireFTP 0.99.1, Web Developer 1.1.6, Fusebox Reload 1.0 and have one additional theme installed (Aero Silver Fox Basic 3.0.1). Firefox has been working like a champ for me. It’s currently using about 75MB (machine has 4GB of RAM) with just two browsers open (your blog and this ‘add comments’ popup). CPU utilization hovers under 2%.
    So far so good with me. I haven’t found any quarks. πŸ™‚

  5. I’ve had one incident of FF3 eating over 50% CPU, but my PC was going crazy at the time, so I didn’t even attribute it to FF. Killed the process and started again, was fine. I’m seeing the same as other comments, FF3 is using far less resources that FF2.

  6. FF3 on Mac (Leopard) and Windows (XP) runs like a dream. I was seriously considering moving to the dark side for a while there πŸ™‚
    I don’t have greasemonkey but I do have YSlow (did you get the new FF3 version?).
    I’d previously removed Firebug as too many sites (including gmail) made my browser crash daily. I’m glad to have this back now in FF3

  7. You don’t have avg8 installed, by any chance? It has an insanely bad ff addon link checker that bogs down FF horribly. You have to do a special reinstall to get rid of it permanently.
    I "upgraded" to avg8 about the same time as FF3 and thought it was FF3 that was the problem.

  8. I’m running Ff3 on XP64 with excellent performance (a noticeable improvement over Ff2). I have Greasemonkey installed along with several other add-ons, but not YSlow.
    I agree with @ziggy regarding AVG; one of the first things I did was disable its LinkScanner feature.

  9. Firebug is really the biggest resource hog. with the beta of 1.2 it’s a lot better, since now you really only enable it for the sites you need it for (opposed to the "fake" disabling of it before 1.2)

  10. I’m using FF3 with FireBug, Web Developer Toolbar and YSlow on Vista Ultimate… and only 3% of my processor resources are being used by Firefox (I’ve a Core Duo 2.0GHz with 2Gb RAM). 75Mb of RAM but I’ve a lot of tabs open πŸ˜‰

  11. I just loaded FF 3.0 on my Windows XP/SP 2 PC along with my web / user extensions and it is rendering my pages faster. I opened 10-30 tabs and the amount of memory is a lot less than 100mb. Are you running other apps along with FF? Sorry about your problems.

  12. Ben,
    I have noticed something similar, though it looks like most people here haven’t experienced it. My memory use has been much better, but I have had 3 experiences where FF3 has been using all about 90% of my processor. Upon a restart of Firefox, the problem has gone away. I assumed it was with one of my extensions, or a small bug that would get fixed with the first update. Like I said, it doesn’t happen all of the time.
    XP pro
    4gb ram
    2Ghz Core 2 Duo
    Here are the extensions I have:
    User Agent switcher
    HTML Validator
    Search Status
    SEO for Firefox
    Web Developer Tool Bar
    Forcast Fox Enhanced
    IE tab
    Quick Restart
    Session Manager
    I think that is all of them.

  13. No problems with FF3 here, Ben. For me, working faster and using much less resources than FF2. I’m using XP and a fresh install of FF3. I’ve added a few addons now, somewhere around 7-9 of varying complexity. I’m thinking the issue is either Vista (which did similar things to me for other applications) or maybe you need to completely uninstall and reinstall FF3.
    Good luck!

  14. I also have same experience. But i have FF2 with YSlow and Greasemonkey. I wonder why is this problem with FF2 but then realized its with my FF2 adds on.

  15. YSlow is notoriously resource-hungry but in the settings (possibly the Firebug settings) you can have it disabled by default and then enable it on a site-by-site whitelist.

  16. I have exact same issue on two different PC’s. I’ve disabled Java and java script, uninstalled all addons and still no joy. It’s totally unusable after 5 mins. So bad I’m going to have to use IE until the next patch turns up.

  17. I am seeing completely opposite to what you have observed with Firefox 3. With currently 20+ tabs open in FF3, my memory utilization is still 150 mb only.. where as it used to reach upto 300 mb+ in FF2. I am observing the system usage closely since I installed FF3, but did not find any weird behvior yet.

  18. I always had/have slowdown/resource problems if I forgot to disable FireBug (I only enable it when I need it)

  19. I have the same problem, ff3 usually takes about 80 to 90% CPU power with Win XP. I’m not using any addons.

  20. Firefox was also grinding my pc to a halt with up to 100% cpu time but I found the problem today. It was one particular site. I always had that site open in a tab but it was a real hog. Once I close that tab it all went to normal. The site had a bunch of mp3 files on it.

  21. Hi Ben,
    This happens to me when doing a significant amount of Flash work in multiple tabs. I’ve particularly noticed it on youTube, where if you ctrl click multiple videos, then it can get messy even to the point where sound dies.
    But we are talking a lot of tabs here 20+.
    I’m wondering if FF3 is not garbage clearing correctly.

  22. I had it running up to 90%. When I checked it in the activity monitor, it war running as PPC, rather than intel. After fixing that, everything seemed to work fine. I would like to think that that’s what fixed it, but I also got rid of FoxyTunes and restarted ff.

  23. I’ve removed / disabled / enabled plug-ins in all combinations. And when I disable both FireBug and YSlow things seem to have gotten much better. I guess I’ll leave those disabled until needed.
    And Fred, StatusbarEx is great, thanks for the recommendation.
    — Ben

  24. I’ve definitely noticed a slowdown with Firefox 3. I’ve installed Chrome Cleaner to increase launch speed, but yes – it does seem to do a lot of crunching and grinding in the background that’s not necessary. I use it because of AdBlocker and some of the other features, but this is getting to be annoying. I run XP Pro on this system, but I don’t dare try it on Vista. One resource hog plus another one equals disaster…

  25. I’m also experiencing the 99% cpu usage with FF3. I use AVG 7.5, so I don’t think that’s it. I have also had a buch of trouble with explorer going to 100%. Now tho, the FF3 keeps causing the lockups. Once I get it closed, I still usually have to do a manual restart.lh

  26. I occassionally notice a major slow-down with FF3, but it seems to be on a site by site basis. I did as someone else suggested an disabled the AVG 8 add-on and the problem seems to have disappeared.
    Anyone else tired of AVG sucking more with every release?

  27. Firefox is still very much a resource hog. Not as bad as it used to be, but definitely needs to be improved. Uses more RAM or CPU than any given application open. I loath IE…but FF needs do address the memory usage.

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