Discussion Is it okay to stack the thermal pads? If yes how?

[pandemicc]

Hi,
I will be replacing various GPUs' and laptops' thermal pads and as you already might know, thickness of these pads vary from laptops to GPUs. I looked on various internet forums but couldn't actually find anything useful. Some say it is okay to stack and some say to put a little thermal paste between them. My intend was to buy only one 0.5mm sheet and stack them as it will be too expensive to buy 0.5mm 1mm 1.5mm 2mm sheets separately.
So what are your suggestions on this?

 

[CountMike]

Hi,
I will be replacing various GPUs' and laptops' thermal pads and as you already might know, thickness of these pads vary from laptops to GPUs. I looked on various internet forums but couldn't actually find anything useful. Some say it is okay to stack and some say to put a little thermal paste between them. My intend was to buy only one 0.5mm sheet and stack them as it will be too expensive to buy 0.5mm 1mm 1.5mm 2mm sheets separately.
So what are your suggestions on this?

Yes, no paste needed or would help. Just remember one thing, pads and paste are actually insulators but they are very bad at that job and let a lot of heat go thru but not 100% of heat. Thicker they are, less heat can go thru. They are there to fill up gaps

 

[drea.drechsler]

Hi,
I will be replacing various GPUs' and laptops' thermal pads and as you already might know, thickness of these pads vary from laptops to GPUs. I looked on various internet forums but couldn't actually find anything useful. Some say it is okay to stack and some say to put a little thermal paste between them. My intend was to buy only one 0.5mm sheet and stack them as it will be too expensive to buy 0.5mm 1mm 1.5mm 2mm sheets separately.
So what are your suggestions on this?

You could go watch a few of Steve's GPU tear-down reviews and cooling mods on GamersNexus' Youtube channel. He's stated it's better to use one pad of appropriate thickness. I think he's stating that based on general principle since each material transition in the cooling path introduces an inherent bit of transfer resistance.

But he's also commented that stacked pads aren't a 'killer' since it's much better than leaving a too-thin pad poorly compressed once everything's installed and tightened in place. At any rate, I don't see that adding thermal paste could help if the gap is bridged by properly compressed thermal pads

 

[USAFRet]

I will be replacing various GPUs' and laptops' thermal pads

If you're doing this in a business context, do it right.
A single pad of the correct thickness.

 

[~cw]

Buying better thermally conductive pads and stacking will have a greater net benefit, I've used Gelid GC-Extreme which you can typically slightly over-size on thickness as their malleability makes them conform to half-mm variations. You certainly can't squeeze a 2mm down to 1mm though (ask me how I know).

May help to get a micrometer if you're planning on measuring to the sub-mm. Vernier calipers have their uses but some are notoriously inaccurate and can drift by a couple of mm during measurements.