# Improving VRM temps by upgrading thermal pads



## Animalpak (Jul 10, 2019)

Hey guys i would like to have better temps with the VRM section of my Asus Impact z97.

I saw this thermal pads that are the same thickness of the original that Asus put on the heatsink 1,5mm :









						Alphacool Eisschicht Wärmeleitpad - 14W/mK 120x20x1,5mm - 2 Stück
					

Alphacools ultimative Lösung (d)einen Computer mit einer Eisschicht zu kühlen. Eine Eisschicht nicht im herkömmlichen Sinne aus gefrorenem Wasser aber eine Schicht die jeden Chip zum frieren bringt. Denn die Eigenschaften der neuen...




					www.aquatuning.ch
				















My question is 14W/K thermal pads ( that are expensive too ) can dissipate better than like a 7W/K ?


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## EarthDog (Jul 10, 2019)

Animalpak said:


> My question is 14W/K thermal pads ( that are expensive too ) can dissipate better than like a 7W/K ?


Quite obviously, yes. What exactly the difference is temp wise, who knows. But the specs clearly show a 14W/K thermal pad moves more heat than 7W/K.

Look at Fujiopoly brand pads.


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## DR4G00N (Jul 10, 2019)

I don't think it would help much (if at all) on that mobo. The heatsink itself is probably what's limiting it since it's just a slab of aluminium.


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## jsfitz54 (Jul 10, 2019)

Examples of Fujipoly:  https://www.newegg.com/p/pl?d=fujipoly


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## TheMadDutchDude (Jul 10, 2019)

It won’t help, as mentioned. It’s limited by the heat sink. It needs a fan to stay cool.


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## delshay (Jul 10, 2019)

Please remember in some cases you don't have to fit the same thickness thermal pad, thinner is better, it just needs to clear the capacitors sitting next to the MOSFET. Plus you need to take into account the mounting pressure of how the cooler is mounted, ie will it spread out those type of thermal pads too thin where gaps may appear.

I use these type of thermal pads on my R9 Nano & you need to understand how they work. I see lots of videos on-line where users say their changed the pads because their broke-up into little bits. Let's make this clear, that's how they work. Those type of pads once fitted & you have used them for a while you must never take the heatsink off again.

These type of pads think of it as if it was cement. After it has set & goes though heat cycles it will harden & dry-up, this is normal. Removing & putting back the heatsink may result it less heat transfer as the pads were disturb. You can remove the heatsink if the pads are new & has not been though many heat cycles, but you can only do this when they are new before they harden.

There is also a art how to mount them, do not compress the pads manually, allow the coldplate & PCB to compress the pads as you screw the two together.

I use 17W/mk of those pads on my R9 Nano & it does make a difference. I can feel extreme heat on the internal plate. It's so hot it will burn your finger, but this is normal because it's transferring much more heat from the MOSFETS via the pads.


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## RichF (Jul 14, 2019)

I replaced the pad on a Gigabyte 970 UD3P board because the VRM temperature was too high when overclocking my 8320E. The only thing Micro Center had in stock was an inexpensive Arctic pad. It didn't help one bit with the temperature.

So, if you're going to replace a pad, don't bother with Arctic pads. I don't know if a Fujipoly would have helped. It seems, though, that thermal transfer ratings for thermal pads should be taken with a grain of salt. Reviews have tested Fujipoly pads against thermal paste and found that the pads performed worse than their rating. (Also, do note that the US government exposed Arctic Silver 5 for not being even close to its rated thermal transfer spec! That was back in 2008 or so and yet people are still buying and recommending it.)


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## vega22 (Jul 14, 2019)

You get bigger heatsinks on nvme ssd dude....

As said, that's your issue not the pads.


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## lexluthermiester (Jul 14, 2019)

DR4G00N said:


> I don't think it would help much (if at all) on that mobo. The heatsink itself is probably what's limiting it since it's just a slab of aluminium.





TheMadDutchDude said:


> It won’t help, as mentioned. It’s limited by the heat sink. It needs a fan to stay cool.


Sorry to say, but both of you are incorrect. Better thermal pads will transfer heat away from the VRM's more quickly and the heatsink will be able to dissipate that heat more effectively. Cooling does help, but the better pads alone will have a measurable effect.



Animalpak said:


> My question is 14W/K thermal pads ( that are expensive too ) can dissipate better than like a 7W/K ?


That is a resounding Yes. However, as has been alluded to above, proper fan cooling is needed for the effect to be maximized.


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## TheMadDutchDude (Jul 15, 2019)

Hmm. I may have to test that theory!


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## delshay (Jul 15, 2019)

If I had the OP motherboard I would go for 17W/mk pads & this is how I would fit them.

I would cut the pads into eight small squares to fit over each MOSFET. I would not use a long strip as that will also cover the capacitors next to the MOSFET. The smaller square pads should give better performance than one long strip as there will be gaps between the MOSFETS. Also doing it this way will also increase mounting pressure on each pad. I would then place the heatsink on the pads not pressing down on it, but before the heatsink makes contact with the pads, make sure the screw holes are align. This part is important as you want little if no movement of the pads moving left, right, up, down as heatsink comes into contact with the pads as this can spread the pads in a direction you may not want.

Do not press down on the heatsink, just screw the two together & compression will take place as you tighten screws,  This is how it is done on my GFX card.

This posting is how I would mount the pads & does not reflect what other end user(s) will mount them. You also need a steady hand as you drop the heatsink on the pads as you don't want to push the pads off the MOSFETS if the heatsink moves, it need to drop direct on top with the screw holes directly in-line. This only applies to the 14 & 17W/mk thermal pads as these are different to other type of thermal pads. Remember these type of pads do not rebound like other type of thermal pads, they leave a permanent footprint after compression. This is why it must not be disturb after compression or worse still after it has hardened.


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## Animalpak (Jul 15, 2019)

delshay said:


> If I had the OP motherboard I would go for 17W/mk pads & this is how I would fit them.
> 
> I would cut the pads into eight small squares to fit over each MOSFET. I would not use a long strip as that will also cover the capacitors next to the MOSFET. The smaller square pads should give better performance than one long strip as there will be gaps between the MOSFETS. Also doing it this way will also increase mounting pressure on each pad. I would then place the heatsink on the pads not pressing down on it, but before the heatsink makes contact with the pads, make sure the screw holes are align. This part is important as you want little if no movement of the pads moving left, right, up, down as heatsink comes into contact with the pads as this can spread the pads in a direction you may not want.
> 
> ...




Wow great man excellent explanation ! I really appreciate that ! You are  a real professional. Everything have sense ! Yes true i saw thermalpads that comes for just one use only. You can see them falling apart when you remove heatsinks from like ram's chips on a GPU or VRM.


Here i did a example on how you suggest to do, correct me if is wrong please :


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## delshay (Jul 15, 2019)

Animalpak said:


> Wow great man excellent explanation ! I really appreciate that ! You are  a real professional. Everything have sense ! Yes true i saw thermalpads that comes for just one use only. You can see them falling apart when you remove heatsinks from like ram's chips on a GPU or VRM.
> 
> 
> Here i did a example on how you suggest to do, correct me if is wrong please :



Show a photo of the heatsink. Is there any raised bumps on the heatsink for the MOSFETS or is it completely flat? If it's completely flat then cut thermal pad to fit MOSFETS only. Do not cover the capacitors sitting next to the MOSFETS with thermal pads.

& how is the heatsink attached? Is it bolts, screws, spring loaded? This is important.


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## Grog6 (Jul 15, 2019)

Make sure the capacitors aren't going to touch the heatsink, that will be spectacular. 

I don't think there's anything to gain by cutting the thermal pad into squares as the caps can use cooling too. 

The capacitance decreases with temperature, so you want to keep them cool.

There's a couple of power dissipation terms, one proportional to frequency called equivalent series resistance and also "tan sigma", which is ESR/Xc, the impedance of the capacitor at the frequency of operation.


			https://www.illinoiscapacitor.com/pdf/Papers/impendance_dissipation_factor_ESR.pdf
		


I'd use the 19W/K strips, and add a fan; if it's too hot to touch, it's too hot.


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## Animalpak (Jul 15, 2019)

delshay said:


> Show a photo of the heatsink. Is there any raised bumps on the heatsink for the MOSFETS or is it completely flat? If it's completely flat then cut thermal pad to fit MOSFETS only. Do not cover the capacitors sitting next to the MOSFETS with thermal pads.
> 
> & how is the heatsink attached? Is it bolts, screws, spring loaded? This is important.



No the heatsink is flat and is covering only the line between the two holes you see in the PCB,  is attached with two screws and a bakplate that do not comes in contact with anything on the back of the PCB. So is just for making it stable.



Grog6 said:


> Make sure the capacitors aren't going to touch the heatsink, that will be spectacular.
> 
> I don't think there's anything to gain by cutting the thermal pad into squares as the caps can use cooling too.
> 
> ...




You have to decide only mosfets or mosfets+caps ? Caps are those brown that are sit between mosfets right ? What are those ?

17W/K are the maximum i found where can i buy 19W/K strips ? 

Ive already put a fan  spinning on the heatsink.

The little blue is for the M.2 SSD to keep it cool, i cant put a heatsink on it because the housing is too thin


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## delshay (Jul 15, 2019)

The capacitors sitting next to the MOSFET are ceramic type. I would not cover capacitors with thermal pads as the main real heat source are the MOSFETS. You will lose performance due-to loss in compression/pressure. Capacitors near MOSFETS are not normally cooled with thermal pads otherwise it would be more widespread in a lot of devices.

The only time you see them covered-up is when it's easier to apply one long strip other than cut them into little bits. This maybe on a production line where time is important per device & little pads are more difficult to handle than one large one. My GFX card has capacitors next to the MOSFET but they are not covered by thermal pads.

To tell the truth, even if you used one long strip of thermal pad, it may still not come into contact with the capacitors. It's all down to type, height of MOSFET & capacitors & the type of thermal pad used. Leaving a air gap is better for the capacitor other than connecting it back to a hot cooling plate.

Either way the capacitor will see little change in temperature as it's sitting right next to MOSFET & the heat source will travel though copper traces back to the capacitor. The capacitor will always be around 1 to 3c cooler than the MOSFET if your lucky.


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