443766 - css background: fixed; causes slow scrolling AND flash/script elements to lag

Status: RESOLVED INCOMPLETE

(Firefox :: General, defect)

Description

[Matt Godwin]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9) Gecko/2008052906 Firefox/3.0
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.9) Gecko/2008052906 Firefox/3.0

When you view the site i submitted the page scrolls slow with the background image even when i lowered the resolution and size of the image to 60%. Also the Flash elements and Script elements within the page (ie: the SHoutbox on the front page) lags behind when you scroll up and down quickly. This does not happen in IE7 at all and scrolls perfect. Basically any website using a fixed background that has Google Ads will experience this too as the Google ads lag behind and overlap other elements of the site temporarly. 

Of course one can not use fixed backgrounds but then this is ruining the web surfing experience as i am sure alot of myspace sites use this feature.



Reproducible: Always

Steps to Reproduce:
1.Load up any website with a fixed background
2. Scroll up and down really quick 
3. compare same site with IE7
Actual Results:  
What happened is the web site scroll very slow and flash elements lag behind and look choppy.

Expected Results:  
it should perform like IE and scroll fast and all elements should stay fixed in there tables instead of lagging and overlapping other parts of the site temporarily.

Comment 2

[Matt Godwin]

It is not a duplicate of 372039. that bug says that the background image is choppy and shaky. My bug says that elements on top of the background image appear to lag behind when scrolling up and down quickly. Also the scrolling is very slow.

Comment 3

[Martijn Wargers (dead)]

Ok, well, I think this still depends on bug 374980.

Comment 4

[Matt Godwin]

Ok well i would not want someone to just close this ticket, but perhaps add the info from this ticket to the bug 374980 then.

Comment 5

[Martijn Wargers (dead)]

Sorry, but I don't think that would be very useful. Bug 374980 might make things better, but not completely fix things.

What would help if you would track the performance of the scrolling with this "scrolltest" bookmarklet that measures (more or less) what the scrolling performance of Firefox is: http://martijn.martijn.googlepages.com/bookmarklets.htm

You could compare it to Firefox 2. Also, if you're into nightly builds, then you could keep track of performance of nightly builds and see if things don't regress.

Comment 6

[Matt Godwin]

Honestly the scrolling speed is not the biggest issue in my bug report. The biggest issue is the different flash and script elements lagging behind and overlapping other portions of the site when scrolling up and down quickly. www.mypawbook.com, have you checked that site in fire fox 3? if you honestly think this is the same issue as that other bug, then i will not debate this anymore.

Comment 7

[Martijn Wargers (dead)]

Ok, I can see that issue on my vista machinge. That seems similar to bug 302377 and bug 302380. Those bugs depend on a fix for bug 352093 and that bug depends on bug 374980.

I'll add a dependance to bug 352093. When that bug is fixed, this one should be solved too.

Comment 8

[Matt Godwin]

I appreciate your time and effort and look forward to this bug being fixed as 1000's of web designers worldwide will jump for joy!

Comment 9

[Sander]

Bug 352093 is fixed, which might mean that this one is too. I find it very hard to reproduce the reported issue though. 
Matt Godwin: Could you test a Minefield nightly - http://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-trunk/ - and either mark this bug as fixed or comment saying that it isn't yet?

Comment 10

[Martijn Wargers (dead)]

Not fixed yet, using:
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20090726 Minefield/3.6a1pre (.NET CLR 3.5.30729)

The problem is that plugins (like flash) still use their own widget, so they still will keep lagging while scrolling. This bug might very well be a duplicate, though.

Comment 11

[Tyler Downer [He/Him]]

Reporter, are you still seeing this issue with Firefox 3.6.12 or later in safe mode? If not, please close. These links can help you in your testing.
http://support.mozilla.com/kb/Safe+Mode
http://support.mozilla.com/kb/Managing+profiles
Also, please consider using the most recent Firefox 4 beta build, your bug may be resolved there.

Comment 12

[Tyler Downer [He/Him]]

No reply, INCOMPLETE. Please retest with Firefox 3.6.13 or later and a new profile (http://support.mozilla.com/kb/Managing+profiles). If you continue to see this issue with the newest firefox and a new profile, then please comment on this bug.