I have an i5 2500k , a gtx 260 , and my cpu cooler is a Scythe Kabuto. Here's the issue i have:
I changed the thermal paste yesterday, after about a year of usage. I tried several ways, pea sized, a rice grain, a vertical line. I experimented with the quantity and the shape.
Before each time i applied the thermal paste, i cleaned the cpu and the cooler with alchohol and a cloth.
The results were pretty much the same with each different application, my temperature was higher than it used to be. I had 28-29~ idle , now i have 40-42~ idle.
The cooler is sitted properly i triple checked everytime. I have done this several times . The paste i use is The Chill Factor Thermalright.
And now to that adds also this weird part : When i use prime95 or intelburntest my cpu temperature stays the same as idle. 40-42 ~ .
But when i use a gpu burn test like Furmark my gpu rises from 50~ idle to 70+++ and immediately the cpu follows to 70 ~.
Also when i play for example league of legends my cpu temp rises to 66~
I use speedfan and HWmonitor.
My motherboard is Gigabyte P67A-D3-B3.
Whats your i5 2500k clocked to and the volts? See if you can move the cpu fan (while its mounted) If it moves a lot you didn't mount it right. It may give a little but thats ok. The vertical line works best for me!
I resetted it back to the default settings after it went that high temp to check if that was the issue. It wasn't. The heatsink/fan doesn't move at all , it's rock solid ! After some research i am starting to think that my paste has degraded. Is it possible ? Its 2-3 years old. It was pretty liquefied when i put it. I don't remember it being that way one year before.