265610 - Scrolling content below a transparant GIF is really cpu intensive

Status: RESOLVED FIXED

(Firefox :: General, defect)

Description

[Ger Teunis]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.3) Gecko/20041021 Firefox/1.0
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.3) Gecko/20041021 Firefox/1.0

Scrolling content behind a transparant GIF is a real slowdown.
My AthlonXP 3200+ with a Geforce5200 has around 90% CPU load.
Performed a testcase with the same site and a transparant PNG> much faster and
acceptable scrolling speeds!


Reproducible: Always
Steps to Reproduce:
1. Go to above mentioned URL
2. Scroll vertically
3.

Actual Results:  
Real slow scrolling and a high CPU load.

Expected Results:  
normal page scrolling speed.

Comment 1

[Peter van der Woude [:Peter6]]

Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7.3) Gecko/20041029
Firefox/1.0RC1

->WFM

Comment 2

[Ger Teunis]

Noticably slow are the scrolls when clicking on the arrows of the verical
scrollbar (and visible on high resolutions).

Comment 3

[Peter van der Woude [:Peter6]]

Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8a6) Gecko/20050106
Firefox/1.0+

Confirming

I didn't have the problem before because I used 16-bit color i/o 32-bit
It makes a huge difference in performace for me (32-it a lot worse)

Comment 4

[Steve England [:stevee]]

Actually to me it seems that the scrolling content behind the transparant GIF
scrolls at the speed it should do; it's the rest of the page outside the GIF
that is lagging whilst scrolling.

Comment 5

[Ger Teunis]

Updated the URL (previous URL disappeared)

Comment 6

[Jasper Lieber]

(In reply to comment #3)
> Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8a6) Gecko/20050106
> Firefox/1.0+
> 
> Confirming
> 
> I didn't have the problem before because I used 16-bit color i/o 32-bit
> It makes a huge difference in performace for me (32-it a lot worse)

This bug may be related to bug 201198.

And checking 201198 with various driver / monitor depths is an excellent idea! 
I'll try it....

Comment 7

[Jasper Lieber]

Attachment: Excellent example of bug 284986

Sorry to be slightly off topic, but the URL for this bug turns out to be the
best example of bug 284986 I've seen yet.  I'd bet they're related.

Comment 8

[Jasper Lieber]

Could this bug be related to  Bug 64401, Extremely slow performance with png
background??

Comment 9

[ArronM (:paper)]

There's been some progress on transparent GIF speeds recently, and it may have
effected this bug.

Reporter, can you try this with a latest nightly?

Comment 10

[Ger Teunis]

(In reply to comment #9)
> There's been some progress on transparent GIF speeds recently, and it may have
> effected this bug.
> 
> Reporter, can you try this with a latest nightly?

It is fixed here, no more high CPU load during scroll.

But I'm still seeing the problem described in comment#4: content in the
transparant gif 'box' is painted before the rest of the content. But that
problem may not be in the scope of this bug?

Comment 11

[Steve England [:stevee]]

Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8b2) Gecko/20050310
Firefox/1.0+
Scrolling up and down quickly with smoothscroll enabled and an MS Intellimouse 4
I can get my CPU usage up to 83%, but at all times scrolling is fast and
responsive. Win2ksp4, axp2400, nvidia gf4ti4400 (71.84), 32bit colour, 1152x864

Comment 12

[Ger Teunis]

Attachment: New testcase, previous not working anymore

Comment 13

[RNicoletto]

This is WFM using Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.10) Gecko/20100914 Firefox/3.6.10

Comment 14

[Virtual_ManPL [:Virtual] 🇵🇱 - (please needinfo? me - so I will see your comment/reply/question/etc.)]

can be marked as dupe of bug #595671

Comment 15

[RNicoletto]

FIXED as per comment 13 and comment 14.