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Thermal Grease - The correct way to use it seems a Mystery

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November 15, 2007 4:26:20 PM

OK-
As from my other post you can see my CPU is running hot under a 50% + load factor. This got me looking into new HS and Thermal Grease.

I've been reading different articles and almost everyone seems to be different. It's almost like it's a personal preference instead of a tested methodology to applying the stuff.

Arctic Silver says a small dot in the center no bigger than 3 / 4 of a BB. Others say apply to the center and spread a small layer all over the CPU’s Heatspread surface with a piece of hard plastic.

So- (for everyone running with low or below average temps)

What is everyone’s method of applying the stuff?
What seems to work best in terms of amount(size) first applied, the locatation where and how(line form, ball form, center, all over, edges, etc..) you place it on the CPU, and the resulting coverage once its spread out after the HS is placed on the CPU.

a c 159 à CPUs
November 15, 2007 4:48:39 PM

Both methods work fine. I use fingernail polish remover to clean the surface first. Then a single drop of paste and a single edge razor blade to smooth it over the surface.
November 15, 2007 4:52:38 PM

You have to think in thermodynamic terms. The only reason for thermal compound at all is that there will always be annular space between the Heat Sink and the CPU, no matter how one laps, polishes or otherwise tries to diminish that space.

The thermal compound acts as a bridge between the heat producer (CPU) and the heat dissipation (heat sink). That said, the amount used should only be enough to accomplish the bridge. More than that will inhibit the heat transfer and less than that will not permit effective heat transfer as trapped air will act as an insulator.

The bottom line: Use only the minimal amount needed to insure good thermal contact and this will vary depending upon the flatness of the surface of the mating parts. In the manufacture of precision parts (especially where parts will be required to be connected across a surface area in a critical manner), flatness is a quality of the manufactured surfaces. such surfaces are usually machined or ground to achieve the required degree of flatness and not always are they machined well.
Related resources
November 15, 2007 5:25:34 PM

Rofl...From the Articsilver site site:

Quote:
1) Initial Precautions
• Don't put it in your mouth.
• Don't give it to children or leave it where children can get a hold of it.
• Keep it away from pets.
a b à CPUs
November 15, 2007 5:48:18 PM

For a Core2Duo you apply a short line of thermal paste.
The methodogy all dependes on the underlying core size and shape which is different from what you see from the top.
A small amount can cover the core.
November 15, 2007 5:59:30 PM

I've done personal testing and found that for me it's easier to just spread it out. You run the risk of air bubbles which is the only reason you use the dot and smash method.. but I feel like I can get a thinner layer of it if I spread it with a card.

Do some independent testing. Set up controlled conditions, measure ambient, find the delta T, and see what works best for you.
November 15, 2007 6:02:27 PM

Ahhh come on... just shhhquisssshh all of it out. And if you run out? Just add water in the AS5 tube, shake it up.. and wellah... more AS5. Lil more runny, but it sure goes a long way... :oops: . o O (or does that only werk with robitussin)
November 15, 2007 6:16:14 PM

Grimmy said:
Ahhh come on... just shhhquisssshh all of it out. And if you run out? Just add water in the AS5 tube, shake it up.. and wellah... more AS5. Lil more runny, but it sure goes a long way... :oops: . o O (or does that only werk with robitussin)


You aren't supposed to mix water? I always thought it was thick so I diluted it! :lol: 
November 15, 2007 6:59:38 PM

Grimmy said:
Ahhh come on... just shhhquisssshh all of it out. And if you run out? Just add water in the AS5 tube, shake it up.. and wellah... more AS5. Lil more runny, but it sure goes a long way... :oops: . o O (or does that only werk with robitussin)

you never know, that might help :lol: 
November 15, 2007 8:11:31 PM

spuddyt said:
you never know, that might help :lol: 


Might help in the aid of frying your board
November 15, 2007 9:12:49 PM

Some years ago I worked in aerospace where they were exacting in prep of surfaces. From that experience I finish lapping after scratches are gone on a flat plate like glass with 2500ASA wet/dry, with soapy water as a lubricant. It comes out pretty well polished. I use 91% Isopropyl alcohol, 2 bucks a bottle from Walmart, for final cleaning with a cotton towel and then apply Arctic to both heatsink and CPU surfaces as thinly as possible with complete converage. I don't claim any dramatic improvement for this procedure but it makes me feel better about being so obsessed over my hot components...
November 15, 2007 10:21:06 PM


Well im more of a squeze down 1 edge then spread across the CPU done that since my first system build in the early 90`s with my intel p133 :sleep:  ok killed that with a P2 233 slot 1 sod the paste :pt1cable:  hehe!! mmmm maybe not might aswell superglued a BRICK to your motherboard!! :lol:  Dont be to fast to laugh next up a P3 500 slot cacky thing another Brick!! :lol: 

Then on to 4 different p4`s socket 478x2 and socket 775x2 :whistle: 

Then my latest a C2D
November 15, 2007 10:30:59 PM

On my Q6600, i tried both line method and spread method around the whole CPU. For me personally there was 0 difference. oh well.
November 15, 2007 10:46:52 PM

I'd tried credit cards, other misc edge type tools and my finger...bottom line is use just what you need and make sure you cover the whole heat sink...I'm running a Q6600 @ 3.0 GHZ with a Thermalright Ultra 120 Extreme...didn't lap anything...applied AS5 to my CPU (not the U120Ex) and spread it around with my finger until I felt it was pretty even. I used less then a bebe of compound. No lapping on anything.

I've been running for approximately 2+ weeks now and my temps are at 30C idle and 39-40 full load with Prime 95.

November 15, 2007 10:47:51 PM

Bare finger or latex gloved?
November 15, 2007 10:49:49 PM

bare finger
a b à CPUs
November 16, 2007 10:47:37 AM

Fingers have oils that are not good for the cooling of the CPU.
Better to put the finger in a sandwich bag when spreading.
a b à CPUs
November 16, 2007 11:17:36 AM

Less is better than too much. Most of the heat transfer occurs in the center of the CPU, it is not critical that it completely covers the CPU 100%. You don't want big gaps around the edges, but getting too much thermal paste can hinder cooling more than helping. Remember also it takes some time for the thermal paste to "seat-in". You should see your temps slowly drop over the first 30 days by several degrees.
November 16, 2007 12:14:22 PM

evongugg said:
Fingers have oils that are not good for the cooling of the CPU.
Better to put the finger in a sandwich bag when spreading.


Yep.. tis what I was getting at.


Side Note: Where in VA? I'm in F'Burg.
November 16, 2007 3:00:55 PM

Because different Thermal Pastes have different characteristics it's probably best to go with the directions on the website or user's manual provided by the manufacturer. My stock AMD had a pretty thick layer of grease on the heatsink and none on the processor, which made the two stick together like crazy glue. I was able to drop the temp on the processor by a couple degrees celcius by using Arctic Silver and following the exact directions on their site.

Use isopropol alcohol at the highest purity you can find and a lint free cloth to clean. Most nail polish removers have fragrances and oils in them which might interfere with thermal transfer if any remains on the heatsink. Good Luck.
November 16, 2007 7:48:59 PM

This just shows us you can always learn something.
August 5, 2008 4:15:24 AM

Great thread, even if it is a little old
August 5, 2008 10:47:25 AM

woodchuk said:
Some years ago I worked in aerospace where they were exacting in prep of surfaces. From that experience I finish lapping after scratches are gone on a flat plate like glass with 2500ASA wet/dry, with soapy water as a lubricant. It comes out pretty well polished. I use 91% Isopropyl alcohol, 2 bucks a bottle from Walmart, for final cleaning with a cotton towel and then apply Arctic to both heatsink and CPU surfaces as thinly as possible with complete converage. I don't claim any dramatic improvement for this procedure but it makes me feel better about being so obsessed over my hot components...


Extremely well said woodchuk and just so you it does make a 2-5c temp difference however you need to move a significant amount of plating off the cpu. I like to spread mine across both cpu and heatsink and then rub them together in a swirling motion to ensure it gets into any low spots. One big element is what they term "spread resistance" which means the heat being less able to disipate, this plate removal and lapping method is one of the critical factors and often the secret of well know overclockers. More important than the overal tempreature drop at idle is the speedy heat dispensation necessary at high clocks. My QX9650 will do 4.5Ghz on the stock cooler but I have set the ceiling at 4.2Ghz because I have to damm well pay for a new one if it dies early.
August 5, 2008 3:55:38 PM

I like to make a pattern of small dots like the 5 face on a die, i.e

. .
.
. .

I make the center dot just a bit larger than the perimeter dots. I generally try to have a bit on the end of my syringe, then just touch the surface in those locations, leaving as I said a bit extra on the center. I feel this gives me the best of both worlds, the heat sink does the spreading, but I have it pre-distributed across the surface.
August 5, 2008 4:18:50 PM

B-Unit said:
I like to make a pattern of small dots like the 5 face on a die, i.e

. .
.
. .

I make the center dot just a bit larger than the perimeter dots. I generally try to have a bit on the end of my syringe, then just touch the surface in those locations, leaving as I said a bit extra on the center. I feel this gives me the best of both worlds, the heat sink does the spreading, but I have it pre-distributed across the surface.


But I would think you'd increase your chance of capturing an air bubble in the middle that way. I'd think it'd be better to just do the larger dot in the middle and leave it at that.
August 5, 2008 4:19:02 PM

I once did the above method on one of my first builds... I have to emphasize the need for small dots on the perimeter not frozen pea size, I ended up with thermal paste oozing everywhere :'( .

Other than that on the 3rd attempt it seemed to give a fairly good coverage, tend to find the... latex I now use to spread sticks to AS5.
August 5, 2008 5:19:42 PM

lol, love the title! "Thermal Grease - The correct way to use it seems a Mystery"
August 5, 2008 6:13:16 PM

closed_deal said:
I once did the above method on one of my first builds... I have to emphasize the need for small dots on the perimeter not frozen pea size, I ended up with thermal paste oozing everywhere :'( .

Other than that on the 3rd attempt it seemed to give a fairly good coverage, tend to find the... latex I now use to spread sticks to AS5.



LOL yea, as I said I just barely touch the small bead I have coming out of the syringe to the perimeter, just enough to leave a spot. Then about bb size drop in the middle, and away I go
!