Flash is broken technology to High CPU usage
It is no question of Operating system you use.
Flash is just broken technology that attributes more to the global warming then all your refrigerators combine.
Flash is running inside browser on Windows, Linux, solaris, MacOSX
it always use 100% cpu time.
If you open multiple pages with Flash then yopu can say goodbuye to all of your
low-power cpu`s and notebook batteries with no regard to OS.
I personally use Flash blocker named Noscript to block All javascript and Flash
in my Seamonkey (and Firefox) browsers.
I turn on both only on selected sites and temporarily for those I visit infrequent
then close browser window for such site and together Flash beast with it.