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I've disabled hibernation, and removed the sleep image file. I shutdown my Macbook Pro (15" retina), unticked the box to open windows on restart, and started my MacBook again. As soon as I'd logged on I went to Activity Monitor and saw kernal_task is using 1GB of RAM.

This is a problem as I use parallels and when using Parallels, Parallels itself uses ~3.5GB of RAM and the kernel_task jumps up to over 2GB of RAM. So I have hardly any RAM left for the rest of the computer and it slows down to a crawl.

This has only been a problem since recently. Before I could run Parallels, Mail, Tweetbot, and Safari all at once (and in Parallels on Windows 7 I was using Visual Studio 2012 and/or SimCity). It was only once I ran SimCity along with the rest that it started slowing down. But now it slows down as I say above with nothing open in Windows 7 in Parallels, let alone VS2012 or SimCity.

Is there a way to see what the heck kernel_task is doing and to cut it down?

Will reinstalling OSX work (without wiping my hard drive first so I can keep my files)? I'd rather not do this as it takes about 24 hours to download OSX Lion on my connection.

EDIT: It's now ridiculous I can't open Parallels at all because after a few minutes the computer runs out of RAM and I'm forced to crash it by holding down the power button. I will offer a 500+ bounty (Can't atm because of the stupid 2 day wait) if that helps.

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similar issue here: when running a memory-instensive process, kernel_task consumes about 2X of process' memory causing the whole system to freeze. –  lynxoid May 15 at 18:30
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