How to Apply Thermal-paste
Tiny dot is all that is needed. . A print like this on CPU is good. No surplus on heatsink. Temp is 50c
Small dot is biggest needed. Print is complete CPU & litte extra. Notice the surplus at top and bottom of heatsink . Temp is 50c too.
Bigger dot that is just too big. Surplus pushed out around CPU. Also on heatsink. And temp is 2c higher at 52c.
Keep in mind all of these are within 2c margin of error. In fact the temperature difference could be as little as 1c or as great as 5c.
Direct Metal to Metal, No TIM Layer In-between!
Be careful not to apply too much TIM. We want only enough to fill the voids in the crystalline structure of the metal where it does not give direct metal to metal contact. We do not what TIM to form a layer between the IHS and cooler base
In case you do not know, TIM heat transfer is not even close to what good metal to metal contact is, but it is much better than what air transfers when there is no TIM in the voids created by the pores of the metal structure.
Heat tranfer ability of different things:Copper is 400 W/(m·K) heat transfer
Aluminum 210 W/(m·K))
Lead is 35 W/(m·K)
Typical TIM is rated 3.5-10.5 W/(m-K) (GC Extreme 8.5W/(m·K), Chill Factor III 3.5W(m-K) in use this is only 1-2c difference in CPU temp)*
Air is 0.024 W/(m·K)
To put that into perspective, any way you look at it metal to metal is 50 times better than TIM:Copper is 47 times better than Gelid GC Extreme TIM & 114 times better than Chill Factor III
TIM is 333 times better than air at sea level.
*i don't know how accurate the W(m-K) ratings are onl TIM, but do know the temperature differences between top 30 or 40 TIMs are all within a degree or two, except for liquid metal variants .. which are a degree or two better.
CPU Chip Size Under IHS
Also keep in mind the area of IHS that transfers the heat from CPU chip is much smaller than the total top of IHS. It varies from CPU to CpU. While Intel chips it is generally a square or rectangular chip in the center part of IHS, AMD CPUs sometimes have the chips in the corners.
Heat Transfer Ability of TIM & Other Materials