Hi, An observation for those who might have trouble: Today, my new Macbook Pro decided to run everything at 1/10th the speed of normal and kernel_task would eat between 4-600% CPU for a few seconds. It would do so very distinctively after a few seconds of high CPU activity, such as scrolling a heavy webpage. Another sign was that I was playing Half Life 2 for a few hours, and while I played, the CPU fans suddenly went dead, and anything graphics or CPU heavy did not trigger the fans. The kernel_task process throttles the CPU, by having it do "nothing" in short intervals. I googled about this problem and saw that it was usually related to thermal issues with the CPU on Macbook Airs. But iStat Menus, and touching the machine told me, it was cold. Rebooting or looking for troublesome programs solved nothing. But then I tried unplugging the machine from power and noticed that the battery was almost flat. I had also noticed that the power lamp on the plug was off (what I thought was normal for this type of plug). After plugging the power back in, it started charging and everything is back to normal. Still, there may be a power management issue with the battery, which is a separate issue. My guess is that the kernel thought that the power was not plugged in, even though this was indicated in the menu bar and so, did not charge, not even after rebooting. When the battery went flat, the kernel_task process started throttling CPU usage. I hope this is of help to anyone.