Way to extrapolate. "I have no problems therefore the rest of the world doesn't either."@Ant P.
Strange, because I have no problems with CPU usage. It seems two Gentoo users have problems.
(Snipped the rest of this nonsense.)
I recommend reading up on this issue because I'm in no mood to start googling and copy&pasting for you. This issue has been there since the first time Kolivas solved it with his -ck tree (which got largely ignored by most devs since their so-called "desktop" consists of an xterm and emacs running on 10000$ hardware.) He worked hard and got far. Hearing this from you is insulting his much appreciated work. Also read up on the extreme performance gains Android users get with BFS.