After trial and errors, and cleaning out the dust filters of my case, the none-OC-d core temperature for the i5-760 settled down in a relatively good range. In general use of the system, including playing games, the temperatures for the cores are:
The cores have different temperatures, 0 and 2 cores running at around the same temperature and so do core 1 and 3. This split is pretty much the same when running P95 load test:
The difference between the two core groups is steady and about 3-4 degree Celsius. Is this normal and anyone else noticing the same "grouping"?
The Artic Silver 5 had been applied by the vertical method, instead of spreading the thermal compound manually. Using this method resulted in much better temperatures than the manual one; so much for my steady hand and vision for spreading the stuff.