151218 - Animated backgrounds cause system to become very unresponsive

Status: RESOLVED DUPLICATE of bug 194627

(Core Graveyard :: Image: Painting, defect)

Description

[Nathan Lineback]

Animated backgrounds are very slow and the system becomes very unresponsive 
(mouse cursor takes 3 or 4 seconds to respond to movement or clicks). System: 
Athlon 950, Win95, Voodoo 5 video card. With video hardware acceleration 
disabled however, the animation is much faster and the system remains responsive 
(of course then everything else is slower and games don't work). 

I have replicated this problem on two other machines running Windows 9x, 
although they do not become quite as unresponsive as the Voodoo 5. One machine 
has an ATI Rage Pro Turbo AGP, the other has a Hercules Terminator 3D. All 
machines are running the latest drivers. Again, disabling video acceleration 
causes the animation to run *FASTER*. 

This problem did not occur for me on Windows NT 4 with an ELSA Gloria Synergy 
AGP video card, so some people may not see this problem. 

The animated background performance had improved a bit for me about a month ago 
(in trunk builds only), but performance in builds after 6/6/02 seemed to have 
regressed.

Speculation:
Mozilla is perhaps using a video acceleration feature that does not work well on 
all video drivers. 
Bug 102321 may have been responsible for the performance increase a while back.
Bug 141786 may have been responsible for the recent regression in performance.
May be related to bug 86319 because all of the problem graphics there also cause 
my system to become very unresponsive, but also run at full speed and 
responsive when video acceleration is disabled.

Comment 1

[Andrew Hagen]

Looks like a dupe of bug 86319. 

Comment 2

[Nathan Lineback]

Perhaps it is the same slowness as bug 86319 but I created this bug in response 
to the recent regression in performance I am experiencing now. The graphics 
listed in that bug seem to have always been slow. 

I went back and checked the older builds that were faster for me. Even though 
those builds rendered my page at an acceptable speed, the animated graphics 
listed in bug 86319 still caused unresponsiveness on my system. 

Perhaps there was some error made in a fix, or perhaps whatever changed recently 
is technically correct and just exposes the slowness problem under my set of 
circumstances, or perhaps it is something else. I will have to leave that to the 
experts to determine.

Comment 3

[Kai Lahmann (is there, where MNG is)]

Reporter: Can you reproduce this bug with a recent build of Mozilla (for
example, 1.4 RC1)? If so, then please comment again with details. If not, then
please resolve this bug as WORKSFORME. Thanks.

Comment 4

[Nathan Lineback]

Yes, it is still doing this in both the latest nightly and in 1.4 RC1. When I
view the page the system becomes very slow to respond.   

Mouse events such as scrolling, clicking on a link, or highlighting text take a
second or two to respond. 
Mouse movements take 1-2 seconds to respond. (Seems to be a tiny improvement
over the 3-4 seconds it had been taking last year)
The animation runs much slower than it should be. 
This all goes away and behaves normally when video acceleration is turned
completely off. 

Same hardware: Athlon 950, 256 Megs of ram, VIA motherboard chipset, Voodoo 5. 
Still Win95, but I confirmed that the same thing happens under Windows 98SE with
the exact same hardware configuration. The only difference with Win98 is that
the cursor movement appears responsive but it still takes several seconds when
clicking on something or scrolling, and the animation is still slow. Again it
speeds up when video acceleration is disabled. This all works fine in Netscape
4.80. 

Comment 5

[Jeff D. Hanson]

WFM:

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5a) Gecko/20030604
(P4-2.4GHz, Intel 82845G integrated)

Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.5a) Gecko/20030606 (P233MMX, S3
Trio64V2-DX)

Comment 6

[Alexander Opitz]

Reporter have you the problems with newer builds and with the latst driver of
your graphic card?

Comment 7

[Nathan Lineback]

Same problem, latest build and the most recent video driver I can find. 

Comment 8

[Alexander Opitz]

It's not clear if this is the same bug, but it looks very similar. So hopefully
it will be worked out.

*** This bug has been marked as a duplicate of 194627 ***

Comment 9

[R.K.Aa.]

Reporter: Was this something you saw only with a nVidia card?
I've been reading the report twice and can't quote understand why it is dup'ed
against bug 194627

Comment 10

[Nathan Lineback]

I don't know what the actual issue was except that is was related to the 3dfx
Voodoo 5 having a poor Windows 9x 2D driver although I observed a similar
problem to a lesser extent on other video cards. For various reasons this is no
longer an issue for me now.