Raspberry Pi 4 Cooling & Overclocking

Raspberry Pi 4 Cooling & Overclocking

It’s more than fair to say the new Raspberry Pi 4, while being an awesome little bit of kit, runs hotter than the previous generations. Depending on your application active cooling might be necessary to get the most out of your hardware! Below I’ve tested both passive & active cooling for the Pi 4, along with a 3D printed case I’ve designed and made available to download for free here:
https://www.thingiverse.com/thing:3723481 or for sale as a complete cooling kit on eBay here: 
https://www.ebay.co.uk/itm/133125848253.

Testing

Stress testing was done using arm-cpuburn-A7 which can be downloaded / installed from: https://github.com/ssvb/cpuburn-arm.

The fan used was a 3000rpm, 40x40x10mm, 5V fan included with the cooling kit linked above. It was either connected to the 5V or 3.3V GPIO pins allowing for either more cooling or for quieter operation.

Raspberry Pi 4 cooling kit including Case, Fan, Heatsink & additional fan connectors.

Case assembled with fan connected to 3.3V GPIO pins 17(+) & 6(-) (Can also be connected to  5V GPIO pins 4(+) & 6(-)).

Each of the following tests were run for 15 minutes in an air conditioned room at 20°C:

1.       Stock Raspberry Pi 4 – No cooling

2.       14x16x6mm Heatsink on CPU

3.       40mm Fan at 5V over bare PCB

4.       40mm Fan at 3.3V over bare PCB

5.       Case, Fan & heatsink, 5V      GPIO pins 4(+) & 6(-)

6.       Case fan & heatsink 3.3V     GPIO pins 17(+) & 6(-) 

 The results are shown below:

Both the stock Pi 4, and Pi 4 with passively cooled heatsink throttled down to 1.0GHz after the first 3-4 mins, all actively cooled configurations ran at the full 1.5GHz stock speed for the duration of the test.

The noise levels from the fan were measured at 25cm and averaged over 20 seconds (any further away and I couldn't  detect the noise from the 3.3V fan):

Overclocking

Overclocking the Raspberry Pi is easy and only requires the addition of 2 lines of code to the config.txt found in the /boot directory. 

All versions should be able to apply a +250MHz overclock, to go any higher requires the latest firmware. Gareth at Tom’s Hardware has already done a great tutorial and an extensive set of CPU performance benchmarks here:
https://www.tomshardware.com/reviews/raspberry-pi-4-overclock-2-ghz,6254.html

I was able to overclock to 1.75GHz using a CPU voltage offset of +0.05V, and to 2.0GHz using +0.10V. To my surprise, nothing else was needed and all stress tests ran perfectly with no crashes or errors!

All the overclocked results shown below were using the case, fan & heatsink linked at the start of the article.

In conclusion, although the raspberry pi 4 runs hot, no cooling is actually needed unless it will be used at 100% CPU for more than 1-2 mins. However, with a little active cooling the new Raspberry Pi can handle a 33% overclock with no issues and no thermal throttling!