Interesting note: I had a computer in China that, without liquid cooling, I "somewhat" overclocked. Just a single core but the temp was running at close to the boiling point of water. No exaggeration. A CS instructor assured me that I could not burn up an Intel processor. Well, I didn't but the sucker was sure the answer to the cold Beijing winters!
What I do know is that temp monitors simply interface with the BIOS temp gauge. Is there one that does so more accurately than the two I mentioned? Note: The number of cores in action does not really matter since I am interested in overall CPU temp.
And please don't worry about me overclocking my multi-cores too much cause there are limits on one's ability to do so. For example, optimal overclocking of a 3.2 GHz. 6-core would be 3.6-3.8 GHz. only.