Uneven Heatsink to CPU connection -> High Temperatures

envy331

Reputable
Apr 21, 2014
1
0
4,510
I am seeing high temperatures from my CPU when idle without any overclock.

I am running an Intel Core i7 CPU 930 with no overclock with a Hyper 212 Evo cooler on top of it and am getting idle temperatures of around 48-50C (with hyper-threading disabled). I cannot figure out why my temperatures are on the high end without any overclocking (CPU is getting 1.0V). The main issue I have noticed from removing the heat sink is noticing that after applying a thin layer of thermal paste to the CPU (multiple times in many different ways and using different amounts of paste) when I look at the bottom of the EVO heat sink thermal paste is seen only in two strips on the sides. The center line of the heat sink shows no evidence that it made contact with the thermal paste (and thus the CPU). The CPU itself looks as though the thermal paste made contact with the EVO heat sink in two lines near the edges of the CPU but seems untouched in the center, agreeing with how the bottom of the EVO heat sink looks. This leads me to believe that either the EVO or the CPU have uneven surfaces.

Any ideas on what could be the problem or the fix? I haven't been able to figure it out and have ensured that everything is on snugly.

The heat sink is on snugly and a new thin layer of thermal paste was put on each time after removing the heat sink and cleaning it and the CPU.
Motherboard idle at 36C
GPU idle at 42C
Room temperature at 23C

 
Solution
Take a straight edge and run it along the bottom of the heat sync. Do the same with the CPU's heat spreader. See if the surfaces are concave or convex. If not, try again with a dot of TIM in the center of the CPU and let the heat and pressure spread it where it needs to go.

If one of the surfaces is not flat, the only remedy is lapping or replacement.

clutchc

Titan
Ambassador
Take a straight edge and run it along the bottom of the heat sync. Do the same with the CPU's heat spreader. See if the surfaces are concave or convex. If not, try again with a dot of TIM in the center of the CPU and let the heat and pressure spread it where it needs to go.

If one of the surfaces is not flat, the only remedy is lapping or replacement.
 
Solution