I would say yes, if you look this power calculator thingy,
http://www.extreme.outervision.com/tools.jsp#cpuoc
it'll tell you the expected power output you will need to be able to remove at stock or overclocked settings. Its not a definite yes or no but its a good guestimate. It tells me that my chip is putting out 137w and apparently at stock the qx6850 is about the same and at 30 degrees I would say you would have a fair bit of leeway.