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Alan_A

Applying TIM to heatsink - best practice?

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A quick reality-check question...  

I'm about to start my new build (probably next weekend, still waiting for some parts to get to my doorstep), and wanted to double check the current thinking on the best way to apply TIM between the CPU and the heatsink.

Have tried to read up, and my current understanding is:

-- Apply a VERY small amount - say, the size of a grain of rice, not a pea like in the old days

-- DON'T spread the TIM by hand.  Instead, place the heatsink on the CPU, and let the pressure do the work

Do I have it right?  Please advise if there's a different/better way to do it.

Please note I'm not worried about the TIM between the CPU die and the lid.  I went for a Silicon Lottery delidded CPU - have done my own delidding in the past, but this time I wanted a guaranteed performer.  So the only issue is the TIM on top of the lid, not under it.

Thanks in advance!

 

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Howdy Alan,

To be a spreader or a dropper??  I don't think it matters much... I've been a spreader for many years, and I've never had a problem.  What matters the most to me (whether I spread or drop) is the viscosity of the TIM.  I always warm it up before application by placing the tube in hot water some time before I work with it.  That makes it so much easier to know the TIM is doing what we want... spread across the interfacing surfaces.

HTH,

Greg

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Ah, interesting - wouldn't have thought of warming the TIM.  I'll be using Coollaboratory Liquid Metal Pro, which in the past has seemed pretty easy to work with, but always at room temperature.  Will think about heating it this time. Thanks!

 

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17 minutes ago, Alan_A said:

I'll be using Coollaboratory Liquid Metal Pro...

Then you shouldn't worry about the viscosity of that TIM.  I thought you would be using a paste between the IHS and CPU cooler.  Press on and keep us posted about your build!

Greg

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Ah, OK, understood, wasn't sure if that was a new way of working with it.   No, I've always used it exclusively, both on my delids and on the heatsink.  So will just work with it out of the tube, like before.

Thanks again - and yes, details to follow once I get to grips with it.

 

 

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18 hours ago, Alan_A said:

A quick reality-check question...  

I'm about to start my new build (probably next weekend, still waiting for some parts to get to my doorstep), and wanted to double check the current thinking on the best way to apply TIM between the CPU and the heatsink.

Have tried to read up, and my current understanding is:

-- Apply a VERY small amount - say, the size of a grain of rice, not a pea like in the old days

-- DON'T spread the TIM by hand.  Instead, place the heatsink on the CPU, and let the pressure do the work

Do I have it right?  Please advise if there's a different/better way to do it.

Please note I'm not worried about the TIM between the CPU die and the lid.  I went for a Silicon Lottery delidded CPU - have done my own delidding in the past, but this time I wanted a guaranteed performer.  So the only issue is the TIM on top of the lid, not under it.

Thanks in advance!

 

 

 

If it's conventional TIM, then research has demonstrated that a small blob in the centre of the IHS, about 5mm wide, is the best. The pressure from the cooler spreads it for you. This way you avoid any possible voids etc.

If it's liquid metal TIM, like Liquid Ultra, Liquid Pro or Conductonaut, then it needs to be spread evenly across both surfaces.

 

 

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17 hours ago, lownslo said:

Howdy Alan,

To be a spreader or a dropper??  I don't think it matters much... I've been a spreader for many years, and I've never had a problem.  What matters the most to me (whether I spread or drop) is the viscosity of the TIM.  I always warm it up before application by placing the tube in hot water some time before I work with it.  That makes it so much easier to know the TIM is doing what we want... spread across the interfacing surfaces.

HTH,

Greg

 

You are right, it doesn't  matter "much". It matters a "little".

It's not about "having a problem". It's about optimal performance, it's about CPU temp. There won't be a huge difference between the two methods, but the blob method is easier and may drop the temp somewhat.

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1 hour ago, martin-w said:

 

You are right, it doesn't  matter "much". It matters a "little".

It's not about "having a problem". It's about optimal performance, it's about CPU temp. There won't be a huge difference between the two methods, but the blob method is easier and may drop the temp somewhat.

You apply it your way, I'll apply it mine.  In the end it's all more subjective than objective... the key is lowering the viscosity of a conventional TIM so that it might better fill the voids left by manufacturing.

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Can't resist adding to the discussions! For a demo of the different techniques, with visual results, see: https://m.youtube.com/watch?v=-hNgFNH7zhQ. I prefer the X method (1:32 in the video). I would personally avoid manually spreading the TIM as you can end up with small bubbles (I learned my lesson with that one).

 

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3 hours ago, martin-w said:

If it's liquid metal TIM, like Liquid Ultra, Liquid Pro or Conductonaut, then it needs to be spread evenly across both surfaces.

Thanks.  As noted, it'll be Liquid Pro.  Just to clarify - does it need to be applied to both surfaces?  Or spread a layer evenly on the CPU lid and let the pressure from the cooler do the rest?  Sorry, am not a newbie but it's been a while, and I'm rusty, so trying to come back up to speed.

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both sides, be very very careful when you mount the cooler , its easy to get a bad mount with CLP or CLU

Bad mount have bigger impact on the temp then how you apply conventional Tim , my personl thought.

 

 

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Curious to know how this turns out Alan.  Currently waiting on my delid tool and liquid ultra to arrive.  First time for me.

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Place a bead of it on the middle of the CPU and then with cling film around your finger, dab it all over the CPU to create a smooth even layer. Voila!

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1 hour ago, vortex681 said:

For a demo of the different techniques, with visual results, see...

Interesting video... I have some questions (all rhetorical, of course).

He uses a piece of plexiglass or acrylic which he presses to show how each method "spreads" the TIM.  Why did he use a sheet of material that could flex and thus skew results?  Why not use a thicker material that would not flex?  How does he know he placed the same amount of pressure on each sample?  How does he know the pressure he exerted is evenly placed (in each example his pressure points - the finger tips - is in a different position)?

One thing we do know from his YouTube video... he made money from it. 

Again, the method of spreading conventional TIM is not nearly as important as the viscosity.  The lower the viscosity during application the better the chance the spread will be even and devoid of "bubbles/pockets".

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38 minutes ago, westman said:

both sides, be very very careful when you mount the cooler , its easy to get a bad mount with CLP or CLU

Bad mount have bigger impact on the temp then how you apply conventional Tim , my personl thought.

 

 

Thanks.  Am trying to recall if I've done both surfaces in the past, or just the CPU.  Honestly don't remember.  Results have always been good, but maybe there was room for improvement.

Am going air-cooled this time - Noctua NH-D15S, which is a big animal, so I'll have to take more care with the mounting than I did with water cooling (have used both custom and AIO).

Came across this video from Coollaboratory on how to spread Liquid Metal Pro - seems familiar, though I think I did the business card method last time.  For this round, will hunt down some lint-free Q-tips.

(Almost) ready for the adventure...  

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5 hours ago, Alan_A said:

Am trying to recall if I've done both surfaces in the past, or just the CPU.

Applying to both sides will almost certainly be applying a lot more than you need - the less you apply (as long as it coats evenly), the better the heat transfer. Too much almost acts as an insulator.

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Yes, good point, thanks - and it comes back to me that in the past, I've only applied TIM to the CPU, not to the heatsink.  Will probably stick with that approach here, so as not to overdo it.

Sorry to seem so obtuse - this is actually my fourth or fifth build.  But the most recent one is nearly three years in the past, and I've clearly gotten rusty.  Aiming to be back up to speed before I take any parts out of any boxes...

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Thanks!  Had stumbled across that earlier today but lost track of the link - good to have it on hand.

I see they leave it up to the user's discretion to coat one surface or both.  I think I'll go with their overriding injunction ("don't use too much") and stick with one only.

Time to order the last of the parts - aiming for a weekend build.

 

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17 hours ago, lownslo said:

You apply it your way, I'll apply it mine.  In the end it's all more subjective than objective... the key is lowering the viscosity of a conventional TIM so that it might better fill the voids left by manufacturing.

 

Of course, apply it your way indeed. Not telling you to do otherwise, As I said, the difference is small, one or two degrees. You are free to apply how you like.

Not subjective though, properly conducted tests do reveal temp differences with different application methods. I refer to conventional TIM, for low viscosity liquid metal see instructions that come with product.

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15 hours ago, Alan_A said:

Thanks.  As noted, it'll be Liquid Pro.  Just to clarify - does it need to be applied to both surfaces?  Or spread a layer evenly on the CPU lid and let the pressure from the cooler do the rest?  Sorry, am not a newbie but it's been a while, and I'm rusty, so trying to come back up to speed.

 

For Liquid Pro they give you the option, one side or both. For Conductonaut, the instructions say both sides. So it does vary dependant on the liquid metal TIM in question. Hence, always refer to instructions that come with the product. 

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Innovation Cooling, the guys that make the Diamond paste that used to be my favourite, did the tests linked to below. They concluded the single blob method in the centre was the best. They also mention how correctly applied, the "line" application method can be effective also.Again, this is for conventional TIM, not liquid metal.

It does also depend on he viscosity of the TIM. With high viscosity TIM's the blob method is even more advantageous. 

 

http://www.innovationcooling.com/application.html

 

 

 

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6 hours ago, martin-w said:

...properly conducted tests...

Please do provide evidence of "properly conducted tests".  Hint... not one of the many YouTube videos the kiddies make up to enhance their revenue stream, or any testing done by a TIM seller.  Please provide valid scientific testing performed by a independent entity.  Narrowing it down the way I have may preclude you from wasting much of your time looking for test data we can actually believe and trust.

Regards,

Greg

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I'm not sure why you're being so intense about this to be honest Greg. It's not an argument. We're not trying to achieve world peace or fix climate change. It's just TIM application. And as I said, we are talking about a mere one or two degrees. No need to be defensive, I have no issue with you applying TIM how you like. No matter what you do it won't be a show stopper. Plus I don't care what you do of course.

 

Quote

or any testing done by a TIM seller.

 

Why don't you want me to provide tests conducted by a TIM seller? A TIM seller isn't going to fabricate the results. A TIM seller wants you to apply "their" TIM is just the right way, a way that it will be most effective. So you can be sure they will advocate the "best" method. They are hardly going to give you bad advice and compromise results from their own TIM now are they. In fact TIM manufacturers are the "best" sources to rely on.

And of course, as you know, I have already provided you with Innovation Cooling test results. You can check them out if you like, safe in the knowledge that it will be the best way to apply their TIM. If you aren't interested in their advice, no problem.

I doubt you'll find extensive, properly conducted tests, from anything other than TIM manufactures, for the simple reason that no one else would be prepared to invest significant funds necessary just for TIM application. The manufactures will because they want you to achieve the lowest temp with their product.

We can also use common sense as well and consider whether voids, air pockets, are more likely if we "spread it around a bit" or leave a blob undisturbed and rely on cooler pressure.

Again, as I've said numerous times, apply it how you like, I don't care. But hopeful the link I provided will be useful for the OP.

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4 hours ago, martin-w said:

I'm not sure why you're being so intense about this to be honest Greg.

One could say the same about you, Martin.  You are correct, it is just TIM application... yet you seem to insist that placing a blob is the "correct" method.  The priority for me is not the method of application but making the viscosity of the TIM as low as safely possible.  Simple as that.

I don't trust TIM sellers recommendations simply because after dealing with the computer industry on a minor business basis for more than two decades I've come to distrust most in the biz.  Any testing to be done on a tech system I want to see done by an independent entity using scientific methodology.  Anything else is pure marketing B.S.  I usually build 5-10 computers a year and just putting a bill of materials together always leaves me shaking my head (my current fav from the industry is the upcoming i9/X299 platform... what a "deal" that's shaping up to be for the consumer).

Cheers,

Greg

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