Applying Thermal Compound

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In the past I have applied AS-5 using a razor blade to spread it thinly over the Processing Unit and then apply the heatink with a little twising back and forth to make sure it is bedded in.

I will soon have some more CPUs and GPUs to do and have bought some MX-3.

From what I have read the favoured approach nowdays is to apply a blob in the centre and then squish and twist it with the heatsink.

Whilst I understand some of the benefits of this approach I'm a little concerned how you know whether it has worked - covered properly.

For example, if you put a blob in the centre of a large square CPU and you squish it down, won't it naturally form a circle - if so either some of the chip will not have thermal compound or you will have compound squidging out.

What method do you use?

Cheers,

Nigel
 
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i tend to smear it over the whole cpu or gpu,i find this better and i know its fully covered also just to make sure i lift the heatsink or block up a little to see it has made contact if not add a bit more.
 
Soldato
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From what I have read the favoured approach nowdays is to apply a blob in the centre and then squish and twist it with the heatsink.
What method do you use?
Always used an old bank card, wafer thin layer across the CPU, always worked for me from using Arctic Silver 1 to 5 & Arctic Cooling MX series.
 
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I used the 'Line' method from the Arctic Silver website.
http://www.arcticsilver.com/arctic_s...structions.htm
I have good temps, 44-79 on a warm day.

Thanks for that link - there are no instructions for MX-3 and MX-2 just use the blob approach.

Interestingly, the instructions (above) for Intel say to use the line method and for AMD the centre blob method.

The instructions also state that this doesn't result in full coverage between the CPU metal surface and the heatsink, just the area where the cores are located.

I'm sure that will work, but I must admit, I'll feel more comfortable with the complete surface of the CPU heatspreader covered, so I'll probably stick to my old method - after all the CPUT retail sinks have thermal compound over the complete heatsink surface not just the area that will cover the cores.

The AS-5 instructions also only cover CPUs so a full spread might be safer for GPUs and other processors.

Cheers,

Nigel
 
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There was an interesting vid posted recently showing how various thermal compounds spread, using different types and methods (using a glass slide so that you can see exactly how each compound spreads across the cpu when pressure is applied).

Was from the tube I think.
 
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There was an interesting vid posted recently showing how various thermal compounds spread, using different types and methods (using a glass slide so that you can see exactly how each compound spreads across the cpu when pressure is applied).

Was from the tube I think.

Yeah, funnily, one of the better ones from that is what I've been doing for the past 2 years, which is the cross method.
 
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i just put a tad bit of it in center and spread it out a little with my ladies make up brush lol. leave a little in center at end so when i lay cooler on it, it spreads it out.
 
Soldato
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+1 for this. But the blob method works because the actual "chips" are in the centre of the CPU, the square that u see is actually an IHS (Integrated Heat Spreader), in case ur interested see here:

(1.1) Well what is an IHS?

IHS stands for Integrated Heat Spreader and is the big metal plate we see on all our CPUs today! It is very heat conductive and rests on top of the actual CPU, which is called the die.

(1.2) What is the purpose of the IHS?

The purpose of the IHS is to spread the heat from the die so its not all concentrated on that small little area, hense the name "heat spreader". It provides a larger surface area for your heatsink or waterblock to mount on, which sometimes means better temps.

http://www.overclock.net/intel-cpus/305443-ihs-removals-how-do-should-i.html
 
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Ah balls i just used the whole tube for my new rig, aint switched it on yet.....

I put a bit in the middle of cpu, then it said to cover the entire heatsink bottom, so i did, next thing you know, none left!

Will my pc explode when i turn it on?
 
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Ah balls i just used the whole tube for my new rig, aint switched it on yet.....

I put a bit in the middle of cpu, then it said to cover the entire heatsink bottom, so i did, next thing you know, none left!

Will my pc explode when i turn it on?

Course not, don't worry. I've never actually ever ran into this problem, the only thing i can see happening is you not getting the desired temperatures on your cpu. It'll work fine, just not as well as it could be.
 
Soldato
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CPUs, blob in the middle and let the weight and pressure of the heatsink spread it for you. All the heat comes from the centre of the chip anyway, I would think a tiny bit missing on the edges of the heatspreader would make little difference. Besides, it always spreads out over the whole thing for me.

If it's not a CPU (NB, GPU etc) I tend to spread as there are more sensitive areas around there and I don't want it squishing out all over onto the surrounding circuits.
 
Soldato
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i tend to smear it over the whole cpu or gpu,i find this better and i know its fully covered also just to make sure i lift the heatsink or block up a little to see it has made contact if not add a bit more.
That method is quite sure to leave air bubbles unless heatsink is rocking on convex surface. (or there's notable excess of compound in center)
http://www.youtube.com/watch?v=EyXLu1Ms-q4
http://www.youtube.com/watch?v=ffK7L0Qj13Q

As whole it's lot better to have good thermal contact in center and metal to metal on edges than air bubbles all over the place.

Interestingly, the instructions (above) for Intel say to use the line method and for AMD the centre blob method.
Reason for that is clear if you look "under the hood".
AMD has used monolithic dies from the start with all cores in one piece of silicon while Intel has used two separate dies next to each others for quads (Q6600 was just two E6600s connected to each others) and those ways are surest to guarantee best contact in thermally critical areas.
 
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Looking at the video of MX-2 being spread under glass, I think I'll go for a small blob/pea really. Makes no sense to spread it. You won't be getting full contact that way.
 
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