The URL above is a link to some DHTML-Tutorial. It features animated images as links. If you move your mouse over the three images at the bottom of the page the animation is very slow (this is especially visible if all three are animated at the same time). While this is quite a stress-test for the browser IE5.5/6 performs very well on that page - check it out for yourself... If you have any questions you can mail me or marcus@gooseflesh.de (he's the webmaster) for more informations. I'll submit another bug for this page concerning layout.

fabian, this is all yours. :)

The key function is printImage(), which does a lot of document.writeln()'s. Not JS Engine per se; reassigning to DOM Level 0 and adding this bug to the tracking bug for DHMTL performance, bug 21762.

I should note, on my WinNT 500 MHz box, the difference between my Mozilla trunk binary 20020213xx and IE6 is not that much if you mouseover the images individually, from top to bottom in each case. The images do animate slower in Mozilla, but I wouldn't have noticed it myself. However, if you mouseover them as a group, from left to right and back, the difference in performance is SEVERE, as huxhorn@mac.com has reported. Note: at the bottom of the page we see the text "Diese Spalte sollte sich nicht verschieben!" which means, I think: "This column should not shift itself!" In IE6 this remains absolutely still when you mouseover the images. In Mozilla, it moves around - I don't know wheter that is related to the present issue or not.

nice JavaScript Performance test-suite: http://www.24fun.com/downloadcenter/benchjs/benchjs.html

Severity = MEDIUM [No Crash, No severe functional failure, Results in Cosmetic failure] Visibility = MEDIUM [Real world website usage, Gets one point of compatibility with other browsers since it works better on other browsers. gets one more point on compliance with adopted techonology, that is JS] Priority = Visibility * Severity Priority = p3 adding word "qawanted" because I'm setting this priority on available data & if someone feels otherwise then please investigate this more & feel free to change this priority.

Using trunk build 2002052308 on win-xp and taking a look at http://www.gooseflesh.de/javascript/examples/example004.html the three animations at the bottom still cause the line "Diese Spalte sollte sich nicht verschieben!" which is saying 'this line shouldn't move!' to move up and down. Isn't this layout related rather than performance?

Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.0.1) Gecko/20021220 Chimera/0.6+ Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en-US; rv:1.2.1) Gecko/20021130 Anim is a little choppy, but fast enough. The text "Diese Spalte sollte sich nicht verschieben!" moves -the real issue. Removing perf keyword. Since this page is in German, it is hard to figure out what is going on. Please provide a simplified testcase (without using document.write) in English.

Mozilla Build ID: 2003020208 Platform: i386 OS: Windows 2000 This works for me. The text "Diese Spalte sollte sich nicht verschieben!" does not move when I hover over the pictures, (although the animations do slow down a bit if all three pictures are animating simultaneously)

Mass-reassigning bugs to dom_bugs@netscape.com

For 1.4 rc1, another URL: http://www.hamsterdance.org/ The display speed of the hamsters is a small fraction of that with IE, and the hamster attached to the cursor doesn't show on Mozilla

http://taphos.angryziber.com/ Falling snowflakes take 100% CPU on 1 GHz Athlon, while IE takes 3-4% A huge difference :-(

Anton, how about now with a recent build?

Firefox 1.0 RC1 seems to work better now, thanks :-)

When I tested http://www.24fun.com/downloadcenter/benchjs/benchjs.html, the pop up window section was hanged up. I tried to close the pop up window and firefox was crashed.

trying to open http://taphos.angryziber.com makes bon echo 'hang' (not crash) MSIE 6 & Opera 9.01 working fine on this. Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1b1) Gecko/20060812 BonEcho/2.0b1 ID:2006081205

forgot to mention: of course tested with a new profile, no background apps running the benchmark on http://www.24fun.com/downloadcenter/benchjs/benchjs.html produces now 'hangs' for me though

grrr, 'produces no 'hangs'' sorry for the spam

all the testcases mentioned in this bug are dead links now. Any updates or should we close this one?

I've uploaded it here : http://bakkap.free.fr/Firefox/testcases/125205/ex004.htm I miss one picture, but you can replace it.

These animations are faster in Fx3 than IE, for me.