CPU Temperature High Overheat

Recently I was hit by something I totally did not expect. My CPU temperature hit 90C. That's in fact way too high under any sort of environment and potentially could burn your CPU. It really puzzles me, because I have a Antec H650 Liquid Cooling system which normally would never even let my CPU goes beyond 60C with full load. Anyway, ever wonder what is your heat, you can always check it with the good old BIOS like this:

Well it might looks better in the new generation BIOS like this :

Well mine was not flagged by the BIOS, but by Asus's utility. This was one time it was fortunate that I did as I could have prevented a fire. So it makes perfect sense to install them even though they do nothing much and basically is used for show off mostly... :)

Anyway, but to the problem. What happened? Well, after cold starting it with a few hours of rest, I can see the temperature going up steadily in the BIOS. This proves something. The temperature probe is likely not damage. It does record the cold starting temperature. It is not likely a software issue, since its in the BIOS before everything starts up.

So I have to take out the CPU connector to the Antec H650. It turns out that this was reused twice from other PC... So the thermal paste has harden for some reason or simply because I did not reapply more when switching PCs... Anyway luckily I bought some from Taobao just for rainy days (and it rained today) and there it goes. My PC is back at 40C. Phew... But guess what? I had already purchase upgrades for her! Well, guess I can still sell the perfectly working Gen 4 I5 away when my B150-I3 comes...