Slice CM3 cooling mods


Well since the CM3 module gets a lot hotter it’s clear that some form of cooling is needed.
Some (including myself) have been modding the slice to fix this.

I think its a good idea to put all the solutions people come up with in one thread. :smiley:

I’ve used 1x 5mm pad stacked with 2x 4mm pads to cover the CM3 module.
This way it makes contact with the top lid and the case dissipates the heat.
All cores fully loaded and i havent seen anything above 66-67° :smiley:

To test for max tempature you can use this code:

fulload() { dd if=/dev/zero of=/dev/null | dd if=/dev/zero of=/dev/null | dd if=/dev/zero of=/dev/null | dd if=/dev/zero of=/dev/null & }; fulload

To stop the heating process use:

killall dd

note: NOT advised to test this on a CM3 without any cooling mods…

ps: I’m working on a better cooling mod so even some overclocking is possible, more on that in a few days.


So I’ve no picture (was a bit frustrated at the end, so no will to take some).

I got a nice little piece of copper (14 * 14 * 12) from scraps in our workshop and some computer grade thermal paste.
Cleaned with a dremmel like the cover of the slice to remove the paint and have access to the bare aluminium.
Degreased everything.
Then put some thermal paste on the cover, applied the copper cube and tried to glue it to the cover.

Tried some PU glue first but seemed like the paste was actually making the glue more liquid. So had to wipe out everything because the cube slipped out of position first time I inclined the cover.

Ended up using some cyanoacrylate glue instead. Seemed to have work.

Only test so far is before when moving my system to the CM3, I could barely touch the chip (above 45-50°C) because it was burning. Now, from Kodi it indicates 35-37°C on the CPU under normal use and the case actually feel slightly warm on top of the chip.

LibreELEC (Krypton) 8.2.0 RELEASE is here

Could you SSH info your slice and use the above code ?
It would be nice to see how mutch of a difference it makes.

Mine hovers around 40-45° when playing media for an extended time.
But once loading all 4 cores to 100% its going quite a bit higher. :wink:


Since there is a place for the heatsink mods now, rather than fill it up, here is the link to the mod I have done
another solution, overkill maybe, but it is cool running!

I have run it at 100% CPU on all 4 cores for over 2 hours and it remains at 49-51 deg with room temp of 21 deg.



Yes, was planning to do so. But haven’t got the time yet.


So, all cores at 100% @ 1300 for 3 h resulted in a max temp of 52C. The case was warm but not really hot (so maybe 40C), I had a classical alcool thermometer on the case that indicated 32C for the air.

In less than one minute, when you kill the script, I was down to 45C.

Questions regarding temperature


Here is a picture of the solution I came up with. A friend of mine made it on his lathe.

It is an aluminum part with a thickness of 12,05 mm. Smallest dia = 20mm, largest 45mm. We put thermal paste on the processor to position it as accurate as possible. Then with some scrap thermal adhesive, we -as accurate as possible- put the top cover on. Then we took the lid off, which now held the aluminum part. Drew a circle around it and then stuck the part with the thermal adhesive on the exact place in the top cover. The result is amazing. So far I have not seen it above 45 degr. wiht the total processor activity around 50% during rebooting/indexing and playing a move. Music playing is at 35-37 degr.

We considered the following:
For best thermal conduct, completely cover the surface of the processor.
For best contact, have a large surface to connect to the top, leaving space for air for the surrounding electronics.
For good level contact the allu. part had to press the chip slightly down as it was not exactly horizontal due to the spring that holds the board.
The spring pressure of the board in its holder would take care of the necessary room to press down on it and level it out.

The exact height of the part was determined by putting it on the processor and closing the slice to see if without pressure the part would stay in place. The tiniest space between body and cover was allowed. After we had decided that 12,05 was correct we assembled it with thermal tape of 0,5 mm thickness. With some fresh thermal paste applied on the processor. When we closed it there was just a minimum of play between the different parts of the slice body before we tightened the screws.This ensured that the allu.part was actually pressing the board a bit down.


That is a bit of engineering equal to the quality of the Slice itself. Very nice, well done.:smiley:



You should make some of these up for sale on here, would it be possible to make them from copper?


Just spoke to my friend who made the part.
First a few small corrections to my write up. The larger diameter is 40mm and the material is Dural. Dural has a little copper in it! My friend has only Dural in his hobby shack. So copper would have to be bought. But… I really don’t think that will improve anything, the thermal conduction to the casing is already so good that the temperature is lower than anything I have read so far.
He believes he can make them for 10,00 euro each incl. postage and thermal adhesive (which is relatively expensive). No thermal paste included. Just PM me and I get you I contact with my friend Ben.



I try to reply to your PM but this is what I get back from the Fiveninjas e-mail server

We’re sorry, but your email message to [] (titled Re: [FiveNinjas] [PM] Cm3 heatsink) didn’t work.

None of the destination email addresses are recognized. Please make sure that you are sending to the correct email address provided by staff.


I fear I am not the good mike :slight_smile: mike != MikeBuzz


Would anyone be interested in ordering the same heatsink as @Fcpiek is using, I will be placing an order in the next few days, works out to about €13 each, which will include the heatsink and thermal tape, will just need some paste when you install it


I would be interested. It’s time my Slice had a speed up.


Hi Mike, I’m really interested in this heat sink, it seems far better than anything I could muster. Do you want to PM me the plan?

Cheers, Matthew


Thanks for replying, the plan is as follows

  1. get idea of numbers
  2. place order
  3. once received items, collect payment and forwarding addresses
  4. post to those that have paid



Would be interested for one of these


I would like one as well


Thanks Mike for organizing this,

Three for me please.


I’ll take one please