Alright, so its what I thought it was. When Valve implemented partial threading they don't wait for the thread to complete its work before joining back to the main thread. If I recall correctly from IRC. They send data off to the worker threads then call wait in the main thread (lol). Tl;Dr I'll try to reproduce the same conditions under the old kernel. However, we may have to roll back if I can't get it right. The problem with Turbo is the engine sleeps for Xms before checking if it should run. When ponging around with Turbo on, the engine does a pretty horrible benchmark at the start and uses that fixed sleep interval. I believe this will only lead to more crashes. If they used join I wouldn't be concerned, and we wouldn't have this problem... Post Merged, Oct 24, 2012 http://www.phoronix.com/scan.php?page=news_item&px=MTIxNDQ Definitely rolling back ASAP.