My Intel i5 661 3.33GHz processor has an idle temp of ~45°C when the computer is on but not running any programs. Overclocked to 4.0GHz running PassMark BurnIn I got the temperature up to 80°C before stopping the stress test. I have tried to do some research but couldn't get a clear answer.
I am second guessing my application of thermal paste and the paste itself. I took another look at the "eXtreme Gamer" paste I ordered for a few dollars online and noticed misspellings on the packaging, i.e. "NO NOT INGESTON," which doesn't inspire confidence.
I am planning to get a high quality CPU cooler for overclocking in the near future, but for right now I am wondering if the temperature I am seeing at stock speeds with stock cooling is normal.
If your cpu passed the stress test at 80c, then you should be ok until you get a better heatsink. Few games get the cpu temps that high. And 45c is right on for the average idle temp. I've never seen any dramatic temp change with so called premium thermal paste, but that's just my experience. If you want to be safe, simply run the cpu at stock settings until your new heatsink arrives instead of removing it or changing thermal paste. The less you handle it, the better. I stopped running my i3 overclocked due to 2 dead ssd's, which windows gave me a temp warning in the task manager.