Closed Bug 425234 Opened 17 years ago Closed 16 years ago

Full page zoom very slow on ajaxian.com

Categories

(Firefox :: General, defect)

Product:
Firefox
Component:
General
Platform:
x86
Windows XP
Type:
defect
Priority:
Not set
Severity:
minor

Tracking

()

Status:
RESOLVED DUPLICATE of bug 487267

People

(Reporter: markus.podar+bugzilla.mozilla.org, Unassigned)

References

(
URL
)

Details

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9b4) Gecko/2008030714 Firefox/3.0b4
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9b4) Gecko/2008030714 Firefox/3.0b4

The full page zoom feature is really very slow and nearly unusable at ajaxian.com. Whether it's zooming in our out doens't matter. Once the factor is not 100%, scrolling the page gets painfully slow and really choppy too.

In my tests it didn't matter whether I was looking at the front page (which indeed is very very long) or on a specific post page (like http://ajaxian.com/archives/tracetool-now-with-open-source-javascript-client).

Reproducible: Always

Steps to Reproduce:
1. Surf to ajaxian.com
2. Zoom twice in
3. Scroll down
Actual Results:  
Very slow, choppy scrolling.

Expected Results:  
Scrolling should be fast. It is expected that zooming is costly, but it appears really very very slow here.

My system specs: IBM Thinkpad Z61p, 1920x1200x32 with an ATI MOBILITY FireGL V5200, Intel Core 2 @ 2GHz, 2GB RAM. I've set my systems DPI to 115 dpi.

I noticed that sometimes other pages are a bit slower because of the zooming, but not as slow as ajaxian appears. To make good use of Firefox I'm really depending on this functionality, because there's usually not single page where I don't have to zoom in. In the past I helped myself with the text zoom, but it was often unusable because the factor I need to zoom usually destroyed the layout.
Still the same with 3.0b5
It works for me. AthlonXP 2500+, 700 MB RAM, GeForce 4 MX, 120 DPI, 1024x768x32. Firefox 3.0.
Exactly the same problem with a website I working on: 
http://www.computeruniverse.net/

Changing the zoom factor causes the page to slow down vertical scrolling. If I remove the CSS completly slow down is not happening. If I remove JavaScript completely slow down still happens, so it must be the CSS.

Is no problem in IE7, IE 8 and Opera 9.5 that have similar features.
(In reply to comment #3)
> Exactly the same problem with a website I working on: 
> http://www.computeruniverse.net/
> 
> Changing the zoom factor causes the page to slow down vertical scrolling. If I
> remove the CSS completly slow down is not happening. If I remove JavaScript
> completely slow down still happens, so it must be the CSS.
> 
> Is no problem in IE7, IE 8 and Opera 9.5 that have similar features.

I can confirm this (running Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.2) Gecko/2008090514 Firefox/3.0.2 ). However some notes:
- the page is scroll clow (=choppy) even *without* zooming. with zooming in, it gets worse
- IE7 is fast/smoother in scrolling but also noticable laggier then other pages
I see this is not confirmed yet? I'd like to confirm, my high-ish-end computer manages about 1 frame per second scrolling with current trunk.

If you remove background image http://ajaxian.com/wp-content/themes/ajaxian/images/bg_main.gif , problem goes away. As you can see it's a tiny (3x3 px) image that's repeated in both directions forever, and it's attached on <html> element and has background-position: fixed.

I'll see if I can make a minimised test case.
If this is caused by the background image, then this bug is a duplicate of https://bugzilla.mozilla.org/show_bug.cgi?id=372039.
(In reply to comment #7)
> If this is caused by the background image, then this bug is a duplicate of
> https://bugzilla.mozilla.org/show_bug.cgi?id=372039.

Yes this page seems to suffer from bug 372039 - it has fixed background and scrolling is not as smooth as it would be without fixed background.

But the problem reported here is not scrolling speed in general, but the unexplained difference in scrolling speed between resized and non-resized rendering. For example (shot in the dark), no image needs to be resized from source data on each scroll step, which might be what's happening here.
I can confirm this on other sites.

Let’s compare with the bugs (I’ve commented more on the first of them.):

Bug 480806 – Scrolling is very slow When the page is made a full zoom.
Bug 483394 - Very slow scrolling/rendering
Bug 452714 – W3C’s page scrolls very slowly
This bug is still there - Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2a1pre) Gecko/20090325 Gentoo Firefox/3.6a1pre
I searched for similar bug reports and here are my findings:

* Bug 479852
* Bug 480806
* Bug 425234
* Bug 426388

And here's another easy way to reproduce the problem:

1) Load your mailbox in Google Mail
2) Full-zoom to 200%
3) Enable the 'Tasks' labs feature
4) Login again to your GMail account with the 'Tasks' labs feature enabled.
5) Scroll now becomes seriously slow.
Scrolling is really slow when you full page zoom on http://www.politico.com/politico44/. 3.5b4pre Build 20090413044519.
Ok, maybe I  will regret for that but I have to duplicate this one to a similar
bug which has a minimized test case. Please don't spam the other bug with
confirm comments.
Status: UNCONFIRMED → RESOLVED
Closed: 16 years ago
Resolution: --- → DUPLICATE
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