I'm currently using Firefox 27.0.1 on a Win XP SP3 machine. At times, FF seems to be incredibly CPU intensive - almost bringing things to a standstill or crawl. Is this normal. Didn't notice it so much with FF 25.
I use the same version of Firefox (27.0.1), and XP Pro SP3, and I don't have this problem. I used to have a problem that it would spike several minutes after booting, just for about 5 seconds, but that went away after I went into about:config and stopped it from using background services to try to search for updates for addons & filters for ABE... even though I had the settings unchecked for it to do so it still tried to. Now it doesn't happen anymore. It also used to happen when I used Ghostery, which I removed a long time ago. I also disable all the Google "Safebrowsing" stuff, both in the options and about:config, and delete the URL's in about:config associated with them. And the same thing with the Telemetry, Health Report, and Crash Reporting stuff.
If it's during video, it's more likely that it's a flash problem rather than Firefox, otherwise I don't know. Never had any non-flash cpu issues with Firefox. Chrome yes, but Firefox no...
Flash would be my guess as well. But one thing that hasnt been mentioned is do you have a security suite filtering web sites? ie an AV plugin
The only time CPU in my XP goes high is when I am using Flash. At no other time, my CPU usage spikes or goes high. I put my XP though a lot more intensive work than my W7 and all feels good. Check the security programs that you are using. Shadow defender and SBIE, your CPU should be 0 at all times but the antivirus or anything else, check them out. Bo
The high usage is specifically coming from firefox.exe. Happens when loading a new site -- or even loading pages and generally lasts from 5-15 seconds, but on occasion it has been much longer.
You may very well be right. I didn't bother to count them, but I probably have at least 10 including NoScript, ABP HeartBleed, Calomel, Flagfox, FEBE, Diconnect, BetterPrivacy. . . and a few others. And I almost always use Sandboxie. So, how do you run FF in Safe Mode?
Too many.. I won't go over 4-5 addons due to this. Click the ? or Help to get to reset if I recall. I don't have FF installed at this time, but its under help or help/about if I recall. The first thing I do on malware removals is to reset all browsers. http://www.wikihow.com/Start-Firefox-in-Safe-Mode
TomAZ, have you checked to see if Firefox is updating add-ons automatically? That could also spike your CPU, given your amount of add-ons. See Check For New Versions Of Your Add-ons.
agreed way to many add on's. like said above disable all of them and start one by one but imo i would get rid of a few of those. also lately i much prefer ad block edge over abp i find it lighter overall.
I have 40 addons on my Firefox, but I don't have problems with it, but I did have problems with some addons. One of those was Canvas Blocker (I couldn't remember it last night, that's why I asked about addons).
Adobe just released a new update today (yet again) of flash for security issues. https://forums.adobe.com/thread/1654544
What are the other specs, like CPU, ram and video card? Is hardware acceleration enabled? Type about:support in your url bar and hit enter. Look at "GPU Accelerated Windows".
Tom, something that you can do to test Firefox without extensions is to create a new Firefox profile and test Firefox using the new profile. The new profile will not have any extensions.You can always go back to the old profile. https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles Bo
I expect the add-ons that "make your browser faster by switching off all scripts" or "speed up your browser by blocking all ads" to be at the source of your slow experience. More often than not, they actually make things slower and more CPU intensive in the end.