是EFI升级导致的 你MAC系统应该是10.10.1 或者10.10.2 beta版的吧

System and System Interrupts- high cpu utilization
kondratk
Oct 15, 2014 6:32 AM
Hi,
I have got a problem with my recent windows 8.1 installation.
Immediatly after instalation two tasks has high CPU usage: "System interrupts" and "System".

I've installed Windows on macs many times and it is the first time i have this problem.
I've tried updating Windows, updating drivers, reinstalling a whole bootcamp package from Apple website- it doesn't work.
Same thing occured on Windows 7.

Maybe it is important that I've used developer preview of Yosemite (which updates EFI), and then I've reinstalled Mac to Mavericks.
Hardware: Macbook Pro Retina 13" Late 2013 / i5 / 8G


原帖在此 你看下吧 里面有解决方法https://discussions.apple.com/thread/6598184?start=0&tstart=0