574692 - Browser slows down when scrolling on a page with big box-shadow effect

Status: RESOLVED DUPLICATE of bug 681226

(Firefox :: General, defect)

Description

[Adeel Ejaz]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv:1.9.2.4) Gecko/20100611 Firefox/3.6.4 GTB7.1 (.NET CLR 3.5.30729)
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-GB; rv:1.9.2.4) Gecko/20100611 Firefox/3.6.4 GTB7.1 (.NET CLR 3.5.30729)

The browser slows down and starts jittering when scrolling on a page using mouse wheel with a big box-shadow effect. Other browsers (Chrome, Safari and Opera) behave perfectly.

PS: Using arrows keys gives smooth scrolling

Reproducible: Always

Steps to Reproduce:
1. Scroll up or down the page using mouse feel

Actual Results:  
A bumpy scroll which results in jittering and sometimes even distorting of the page.

Expected Results:  
Smooth scrolling

Comment 1

[Adeel Ejaz]

Just forgot to add.. removing box-shadow does give smoother scrolling.

Comment 2

[stellariumfan]

Attachment: test case for Bug 574692

I confirm the existence of this bug on Linux using 3.6.6. The slow scrolling only appears when content is placed under an element with box-shadow set. Furthermore, using the arrow keys to scroll only makes the problem more noticeable for me.

The bug is resolved in v.4 beta 1. If the fix can be ported to the 3.X line, that would be great.

Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.6) Gecko/20100628 Ubuntu/10.04 (lucid) Firefox/3.6.6

Comment 3

[Marco Castelluccio [:marco]]

There is a really similar issue in bug 681226 with latest versions of Firefox.

Comment 4

[Wayne Mery (:wsmwk)]

Do you still see this when using current version?

I don't see slowness nor CPU spike using current nightly on win7

Comment 5

[Mark Banner (:standard8)]

This is probably close enough to bug 681226 that if it isn't works for me by now, we can call it a dupe.