Upgrading to Mac OS X 10.10 Yosemite: Fix For High CPU and RAM Usage, Slow Shutdown ProblemsUpgrading to Mac OS X 10.10 Yosemite Mac OS X 10.10 Yosemite was released on the 16th October 2014. The new OS by Apple comes with a number of new features and a complete redesign of the operating system layout. Being a computer enthusiast,