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I'm in YouTube HTML5 trial, and the experience is terrible with Safari.
Every video is lagging severely, and the browser gets unresponsive constantly.

I have zero problems with the Flash version, and Chrome handles HTML5 YouTube just fine.

Activity Monitor says QTKitServer - Safari Web Content grabs more than 100% CPU.
Can I fix this?

image showing 100% cpu usage

I have 17-inch Mid 2010 MacBook Pro running Mac OS X Lion 10.7.2 with 8 GB of RAM.

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You should report your experiences via the "feedback" link on that YouTube HTML5 web page. – bneely Jan 22 '12 at 0:24
A bit more info on your computer could be useful too. OS version, model, year, etc. – kevin9794 Jan 22 '12 at 1:23
@bneely: thanks. I just reported it. – Dan Jan 22 '12 at 3:02

I had a similar problem with my Safari. I went into /Library/Internet Plug-Ins and removed the two piece of Flash cruft (regretfully I'm at work, so I don't the exact file names.) After a reboot, Safari worked much better, as did Chrome. Not sure why Chrome improved, but it improved most of all.

Incidentally, I thought I was on a Flash free system previously, so I'm not sure how those bits got there. If I need Flash, I just go to Develop -> Open Page With -> Chrome (you need to enable the Developer Menu, under Advanced in Preferences.)

Hope this help

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Cool, thanks. I'll definitely try this out. – Dan Feb 17 '12 at 20:55

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