I bought a raspberry pi 4 case, and it came with these heat sinks you see in the picture + a fan. From the sizes, I guess the flat heat sink is for the CPU. I kind of find it hard to believe that this works at all, and I'm more inclined to use one big heat sink with spikes for the CPU rather than this flat heat sink. From my understanding of physics, the reason why the heat sink with spikes cools is because of the high conductivity of aluminum + the increased surface area.

Anyone tested this flat heat sink? Does it really work?

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    I'm pretty sure that's for the RAM chip on the bottom of the board. With any kind of case, there's no room for fins on the bottom. As far as I know, there's no way to read the temperature of the RAM with software, so testing would involve external measurement.
    – Bob Brown
    Dec 24, 2019 at 12:35
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    @BobBrown I'm sorry, I don't understand what you mean with "bottom". There's 4 chips on the board which fit perfectly with the sizes of the pieces I have. Where is the ram chip you're talking about? Isn't it the long black chip beside the CPU? If that's it, then the long piece with fins is for it. Dec 24, 2019 at 12:48
  • Turn the board over. Near the middle will be a black chip about the same size as that flat plate.
    – Bob Brown
    Dec 24, 2019 at 12:59
  • @Bob there are no chips on the other side. Dec 24, 2019 at 13:05
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    the correct term is heatsink, not plate
    – jsotola
    Dec 24, 2019 at 22:53

1 Answer 1


Ah let me see. If the "flat plate" comes with the Rpi4B case, then there is a big chance that it is for the "cpu". There are electronics hobbyists shops that sell thick flat copper plates to be placed on top of the cpu, then aluminium heat sink and/or cpu fans on top of the flat guy. Expensive copper "sinks" (transfers) heat faster and can "store" more heat energy than cheapy aluminium. (Don't ask me how come copper is "stronger", because me poor Rpi guy don't know nothing about physics! :)

rpi4b copper

You might be surprised to check out know how copper plate compares with big cpu cooling fans.

Copper Plate hest sink comparing with cpu cooling fans

copper plate


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