From Bugzilla Helper: User-Agent: Mozilla/4.76 [en] (Win98; U) BuildID: 2000111604 (this has existed prior to this build) After going to a page with a mixture of animated gifs and non-animated gifs, Mozilla uses large (up to 80%) amounts of CPU. It uses everything I have up until the page is fully rendered. Then it settles down to using 50%-80% of my machine! This happens in Win98SE & Win00. It gets worse the more images on the page. Try http://www.neptunescove.org/, it consumes even more of my machine. If I pull a few graphics, the CPU usage goes down a little. I believe it is the combination of multiple animated gifs and non-animated gifs that is the problem. Reproducible: Always Steps to Reproduce: 1. Go to link provided, i.e. http://www.neptunescove.org/Testing/mozilla_cpu_test.shtml Actual Results: CPU goes to 90% until page is fully rendered. Then settles down to 50%-80%, depending on the number of images on the page. Expected Results: CPU usage should go down to 1-2%, as it does when I go to http://www.mozilla.org View the source at http://www.neptunescove.org/Testing/mozilla_cpu_test.shtml. This page was constructed to demonstrate the problem. It is basically a number of gif images on a single page (the Table tags do not seem to matter, they were left in to show how images were relative to each other on the rest of my site). I would like to convert to Mozilla as my default browser, but I can not use it on my own site! This is the last show stopper in my migration and I would really love to get on a complient browser! FYI: When working on my site using HomeSite with the NGLayout embedded browser, I do not see this high CPU problem. It is just under the Mozilla browser!?!?!?

On Linux Build ID 2000112408, I still see this problem (at least, increased usage - can't verify exactly numbers)

not a blocker win98 2000112404, am not seeing this. Could you get a newer nighty and check? Also, does creating a new profile and launching with it fix this? thanks!

Still a problem in build 2000112508, but CPU percentage has dropped to 25-35% when it is in foreground and 4-5% when in background. Netscape 4.7# and MSIE both idle in the 4-5% rage (both in foreground and background). I created a new profile and retested. Interesting! The new profile never jumps up beyond 25-35% when downloading the page (but it is much slower then the original profile that will use 75-85%), but idles at 18-25% foreground and the same 4-5% background. Lauching the original profile still uses the high CPU while downloading the page, but now idles at the new 18-25% foreground!?!?! I deleted the new profile and the old still stays in the 18-25% range in foreground. I am running these tests in 1600x1200x32bit. I retested under 1280x1024x8bit and the number went from 18-25% to 45-55%, at 1280x1024x16bit it is 35-45%, at 1280x1024x32bit it is about 14-16%. Back to 1600x1200x32bit I am back up to 45-55%!!! Purging the cache does not seem to help. But just for fun I manually deleted the contents of the .../user/profile/cache/ folder and now I am down to 15-18% when idealing in forground, when I move it back ground, it is back to 4-5%, back to foreground and it is up to 45-55%!?!?!? Disabling the Disk Cache at this point does nothing. Re-enabling disk Cache, still 45-55%. Manually re deleting the contents of the Cache, an restarting, still 45-55%. FYI: I am running a Voodoo3 with the current GA drivers in both Win98SE and Win00.

ok, let's try this: go to your windows directory and delete moz*.dat. Does that help?

This might be a duplicate of 44588(Animated GIF's Animate Very Slowly) or 58334 (Animated Gif rendering is slow, mention of "It uses up to 92% on Duron 950" in the comments). It seems to be an animated gif performance problem. Removing the two animated gifs on the page drops the CPU usage to 0%. It also seems that removing the TABLE tags around the images drops the cpu usage to around 5%. maybe there is an issue with animated gifs inside tables? I had a high 50% CPU load, but now cannot reproduce it with the same settings. The same page gives a load of 20% (Windows 2000, build 2000112508) It also seems to depend on screen settings, 32bit graphics seem to give a much higher load.

I deleted the two moz*.dat files in my C:\Windows directory. Still same high CPU 40-50%.

looks a lot like the imagelib bugs mentioned.

its a dupe, but I don't have the bug# right now.

*** This bug has been marked as a duplicate of 44588 ***

Verified Duplicate