Terrible flash performance

[Vladimir Nikšić <vniksic@xxxxxxxxx>]

I have an ongoing problem with flash performance. I tried installing 
flashplugin-11.1.102.55-1 from the pacman repositories. The videos on 
youtube for example, works fine as long as I don't turn on fullscreen. 
The video gets really choppy and the CPU usage spikes to 100% (one 
core). I have a Core2Duo on 2ghz. A couple of months ago I switched from 
Ubuntu where youtube was working essentially flawlessly, fullscreen or not.

The same issue occurs on manually downloaded the latest 64bit 
libflashplayer.so from adobe's site. Does anyone have similar issues? I 
also have an Nvidia card which unfortunately does not support GPU 
acceleration.