I have been experiencing high CPU usage (138%) on my MacBook, while looking at flash videos on the internet with the Firefox browser. Mostly this usage makes itself noticeable by the loud noise of the fans and a hot MacBook which is very annoying for me.

Does anyone know how to solve this problem or a workaround in of any kind?

  • 138%??? ^^ anyway, flash playback is a very demanding task and high CPU usage is quite normal. IMHO flash is an outright pain in the behind. – Molly7244 Dec 27 '09 at 1:00

You can try using a Flash Blocker (eg. FlashBlock for Firefox, ClickToFlash for Safari - loads the H.264 files using QuickTime instead!) to help alleviate the CPU spike caused by ads. However in terms of just the spike caused by using Flash, you can try upgrading to 10.1 (available at labs.adobe.com). However there isn't much alternative beyond Adobe improving the performance of their plug-in.

  • ClickToFlash is fantastic. In WebKit nightly it lets you watch videos in full screen without melting the CPU. – Kornel Dec 27 '09 at 13:59

upgrade your flash plugin. the new beta has much better cpu usage.


You can increase the sessionstore interval in firefox about:config which works great for Youtube, and I have seen it make a difference on other flash based items as well. Here is a write up on it. http://www.firefoxfacts.com/2009/08/24/speed-up-flash-videos-in-firefox/


Generally flash takes up that much CPU as a web browser plugin. Try saving the flash file and loading it in an external player.


I don't think there is a single solution and this is a problem that lots of people complain about. It appears based on tests run by Jan Ozer that Safari is more efficient than Firefox for playing flash videos and upgrading to Flash 10.1 is better for all browsers.

There are even bigger CPU savings if you can find the videos delivered in H.264. YouTube, for example, has a beta test that lets you sign up to view videos in H.264. Of course only browsers that support HTML5 and H.264 (e.g., Safari and Chrome) can do this.

Like you I use Firefox and it is a pain to switch to another browser but if I am opening the browser just to watch a long video sometimes it is worth it.

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