Thermal Grease: To spread or not to spread

Shyfe

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Jul 28, 2007
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I have some Arctic 5 ready for my new system and I was looking up how to apply the thermal grease. It seems that some of them say to put a dab on the middle and just put the heatsink down and it will spread it naturally. I imagine that would result in it spilling over the edges and some not getting covered. The other method was to spread it with a credit card and then people were saying that it would result in bad coverage. Which way is the best to do it?
 

jcknouse

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If you want my suggestion?

Take you a well-laminated card from a deck of poker cards. One that is flexible, thin, and well coated with plastic as not to stain it.

Put a drop of Arctic Silver 5 thermal compound about the size of a grain of rice on the center of the top of your CPU. Then, take the playing card and spread the grease one direction (meaning, left-to-right, or top to bottom) as to make sort of a band of compound across the top of your CPU.

Then, spread the perpendicular directions to that band of compound to spread it across the top of the whole CPU.

Note: The reason I say to use a plastic-coated playing card is that it is VERY flexible and will bend to somewhat of a flat surface and distribute the dragged thermal compound more evenly. It is also easier to get the compound thinner with a flat surface than a hard edge, as is found with using a credit card.

Good luck with this. If you do it right, it really makes a difference.
 

jcknouse

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Thanks...but I did leave one little note out though.

You want to optimally make the layer as thin as possible yet still cover the entire top of the CPU. This is because compound is made to fill in the microgaps between the CPU and HSF. Air = bad thermal conductor, thermal paste = better, metal-to-metal = best.

Nonetheless, also make sure your layer of thermal compound is as thin as possible while still entirely covering the top of the CPU.
 

Kithzaru

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I could be wrong, but i was with the understanding that putting a rice sized dab in the middle and just mushing the HS to the CPU was best, especially if you consider that the actual CPU die or whatever is much smaller than the entire surface you see on top, therefore it's not important to make sure the paste reaches the very edges...
 
You have to understand what the paste is doing. It's there to replace any microscopic air pockets. The least amount that will cover the entire surface is the best amount.

Arctic Silver has instructions for everyone that is very clear.
http://www.arcticsilver.com/arctic_silver_instructions.htm

That pretty much applies to any paste you have, just not the bare pipe type of coolers. The Mugen is a solid base cooler I think.
 

Shyfe

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Yes, I understand exactly what the paste does, but I still dunno whether spreading it is better or not. What I'm imagining is that if you leave it as a tab and shove the HS down, it will naturally fill in the microscopic gaps on both the CPU and the HS, but if you spread it on the CPU, it may not spread to the spots needed on the HS. Of course this is just what I think and nothing is more conclusive than testing or experience so I was hoping someone could give me that knowledge.