625100 - firefox process shows very high cpu usage when playing flash video

Status: VERIFIED DUPLICATE of bug 591687

(Core Graveyard :: Plug-ins, defect)

Description

[Markus Hossner]

User-Agent:       Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0b8) Gecko/20100101 Firefox/4.0b8
Build Identifier: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0b8) Gecko/20100101 Firefox/4.0b8

When I play a flash video with Firefox 4.0b8 the cpu usage of the firefox process is extremely high. Firefox 3.6 shows less cpu usage.

My setup:
---------

Mac OS X 10.6.6
Firefox 4.0b8
Flash 10.2.152.14
Test Video: http://labs.adobe.com/technologies/flashplayer10/stagevideo.html 


Results (percent cpu usage):
----------------------------

Firefox 4.0b8: 53%
 - itself 40%
 - plugin process 13%

Firefox 4.0b8 (fullscreen video): 25%
 - itself 6%
 - plugin process 19%

firefox-4.0b10pre: 38 %
 - itself 30%
 - plugin process 18%

firefox-4.0b10pre (fullscreen video): 20%
 - itself 3%
 - plugin process 17%

firefox 3.6.13: 25%
 - itself 25%
 - no plugin process

Safari 5.0.3: 14%
 - itself 4%
 - plugin process 10%


Also the video is playing in a seperate process the cpu usage of the firefox process itself is very high.

Reproducible: Always

Comment 1

[Henrik Skupin [:whimboo][⌚️UTC+1]]

I can see the same on my machine with Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:2.0b10pre) Gecko/20110112 Firefox/4.0b10pre ID:20110112033217 and Flash 10.1.102.64.

Compared to the above numbers the plugin process is even higher for the 10.1 build of Flash (without hardware acceleration). It reaches nearly 60% load when watching the video on the example URL.

Beside the above seen behavior why is the cpu load lower in fullscreen?