Why is Firefox using 50% of my CPU?

EliteLamer

It just started doing this about a day ago, after running firefox for about 20 min it starts to use 50% of my cpu for no reason and I can feel lag my computer down. When I close firefox everything returns to normal.

amateurhour

They just had an update the other day, maybe it glitched something?

Can you see the updater running in processes? Or have you tried reinstalling?

Willeth

Firefox has had a pretty huge memory leak for quite a while. It's something that they claim to be fixing in an upcoming update.

stigweard

There used to be a bug with flash that would eat 100% (50% on a dual core) of your cpu until the page went. I'm not sure if it is patched or not, but is there any chance you are leaving a tab open on a site that uses rotating flash ads?

EliteLamer

Yeah I have a dual core AMD and it only happens sometimes. I just updated a few days back, must be bug in the update. Yeah I leave tabs open all the time and thats the only time it seems to happen.

fightinfilipino

Willeth wrote: »

Firefox has had a pretty huge memory leak for quite a while. It's something that they claim to be fixing in an upcoming update.

it's not a memory leak. firefox is purposely making use of available memory, relinquishing memory as necessary when other programs need it. it isn't eating up all available memory, but when the memory is there, firefox is utilizing it. someone over at mozilla said that if a program isn't making use of available memory, somethings wrong. this is pretty well documented already by mozilla.

CPU thrashing on the other hand is a different problem. if you haven't already, check to see if you're running the most recent version of firefox. also check to see if your installs of Flash and Java are the most up-to-date installations.

Willeth

Well then, ignore me. While that still sounds like spin, I'm not really a programmer. I'd be of the opinion that while it'd be great to use as much memory possible, it shouldn't interfere with the machine as a whole, and maybe it needs to be curbed.

EliteLamer

Firefox is only using 60mb of ram.

Zoey

I had this problem for awhile and I solved it today.

For me Firefox was using whatever CPU it could gobble up. I did some surfing and it seems like there are several different causes for this problem. BUT it was really Google Desktop that I had installed to work with Firefox that was the problem. This was hard to detect because Process Explorer would not show the Google Desktop.exe as the actual culprit and was lumping it in with other programs I had to use Security Task manager to show what was really hogging the CPU.

1. Corrupt Zip files
2. Corrupt .EVT files.

To fix and trouble shoot this problem pick up two tools.

Security Task Manager

Filemon

Security Task Manager will let you confirm that it is the Googledesktop.exe which is a task bar icon program which is gobbling up the CPU.

Filemon will tell you what file is being accessed over and over.

For me it was an hes.evt file, other people are running into problems where google desktop can't spider a corrupt zip file so you have to use filemon to see which one it keeps reading and confirm that it is broken and get rid of it.

For me, I deleted the hes.evt (an event file) and it made and new one and stopped hogging all the cpu.

-Zoey