What difference will a Raspberry Pi cooling solution actually make?

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I’ve been seeing a lot of Raspberry Pi compatible fans and heat sinks being sold on websites such as eBay, Amazon and ICStation, and I have always been very hesitant towards using one simply because it seems to work fine without one. I’ve never overclocked my Pi, therefore never really felt the need to use one. However, I went ahead and got myself a few cooling accessories anyway because I was very curious about what actual difference it would make to the temperature of the CPU and overall performance.

So I designed a simple experiment: I would put the CPU at full load for 10 minutes using different cooling solutions. For this experiment, I bought a rather large heatsink, thermal paste and a mini fan.

Method

I might as well show you exactly how I took these readings.

  1. I attached the cooling solution to the CPU of the Raspberry Pi
  2. I put the CPU at full load. To do this, open up the terminal and type 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; read; killall dd. This will stress your CPU to it’s full capacity and will produce a lot of heat!
  3. After 10 minutes, I stopped the test by pressing ctrl+c .
  4. I recorded the temperature of the CPU straight after. To do this open up the terminal and type vcgencmd measure_temp.
  5. I waited until the Pi was completely cool.
  6. I repeated for each cooling solution.

No Cooling Solution

dscn4053Without any cooling solution the Pi got to a temperature of 55.1 degrees, which is hot but not in any way dangerous. As a general rule of thumb, a CPU should never get hotter than 60 degrees. Any hotter than 60 and you’re in trouble!

Heat Sink

I did have a few problems with attaching the heatsink, and gave myself a small 1electric shock. This was because, when attaching the heatsink, I first put it at a slight angle which meant it sat on top of other components on the board. Metal is conductive, so it connected those components together. When touching the underside of the board, it has short circuited or something of that sort, and gave me an electric shock through one of the components. Do not be stupid and repeat what I did, just be careful when attaching the heatsink especially if it is larger than the CPU itself.

With a heatsink the CPU hit 47.6 degrees. To me this is a very disappointing result being as it was only 14% cooler. To me, it is not worth buying a heatsink as there really was not much difference.

Fan

I could not find a way of properly attaching the fan, so I placed it on top of the CPU dscn4054and hoped for the best.

With a fan the CPU was 43.9 degrees, better than when with a heat sink but still not quite as cool as I would like it to be.

This is 20% cooler than with no cooling solution.

Fan and Heatsink

Because I was so disappointed by the previous results, I thought I would try using both and seeing if that would be any better.
3I was expecting this to do terribly, as the way I attached them to the CPU was terrible. The heat sink was only touching a small part of the CPU, meaning less heat dissipation was possible. Also, the fan was only really cooling the heat sink, as it was stood upright, not facing the CPU. This solution however gave me the best result.

With both the Pi’s temperature was 31.5 degrees, which is 42.8% cooler than with no cooling solution!

Conclusion

Despite a cooling solution making quite some difference to the temperature if setup properly on the Raspberry Pi, the results were still disappointing unless using a fan and heatsink which was awkward to setup and made the Pi look not quite as elegant. That would also prevent it from fitting into a case.

So, in my opinion, it isn’t worth cooling the Pi unless you’re doing overclocking which will produce a significant amount of heat and be dangerous if it is not cooled sufficiently.

Watch a video about this here on my YouTube

You can get a fan from here

You can get a heat sink from here

You can get thermal paste from here

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