Bug 24956

Summary:

CSS Transition perf bad in combination with CSS gradients on MacBook Air / lower end graphics chips

Product:

WebKit

Reporter:

Faruk Ates <farukates>

Component:

CSS

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED DUPLICATE

Severity:

Normal

CC:

dino, simon.fraser

Priority:

Version:

528+ (Nightly build)

Hardware:

Mac

OS:

OS X 10.5

URL:

http://farukat.es/bugs/webkit-css-grad-trans-perf.html

Attachments:

Description	Flags
Reduced test case	none
Test case showing that giving the HTML element a background color fixes the issue	none
Third test case, using a gradient on the HTML element	none

Description Faruk Ates 2009-03-30 19:14:01 PDT

CSS Gradients can cause a significant slowdown in rendering performance when using CSS Transitions, but this is predominantly noticeable on the MacBook Air and other computers with integrated graphics. 

Moving an element around that sits on top of a gradient causes serious frame rate drops (as measured with Quartz Debug). On a solid background it transitions smoothly.

Comment 1 Faruk Ates 2009-03-30 19:47:26 PDT

Created attachment 29108 [details]
Reduced test case

Comment 2 Faruk Ates 2009-03-30 20:02:36 PDT

Created attachment 29109 [details]
Test case showing that giving the HTML element a background color fixes the issue

Added a second test case that sets a solid color on the html element, which makes performance snappy again. Using a gradient (third test case, soon to be attached) as opposed to a solid color, makes it go slow again.

Comment 3 Faruk Ates 2009-03-30 20:03:02 PDT

Created attachment 29110 [details]
Third test case, using a gradient on the HTML element

Comment 4 Simon Fraser (smfr) 2009-04-23 23:03:08 PDT

Same cause as bug 24130.

*** This bug has been marked as a duplicate of 24130 ***