HOT OR NOT! Fans or Fanless Heatsink Pi4 Options

A side by side temperature comparison (Yes, really, these were placed GPIO side also!)

For many who purchased the early versions of Pi4, you may have experienced some unusually high temperatures or overheating.

Throttling was set at 60 degrees celsius but could be modified in the /boot/config.txt file. One pi4 owner reported temperatures as high as 92° Celsius or 197.6° Farenheit (That is *almost* as hot as it gets here in Arizona during the summer months! :D}

Others did not experience higher temperatures.

A few options were available to reduce temperature:

  • Turn the pi on its side
  • Add a fan
  • Absorb and dissipate with a heat sink

You could stress test the pi. I chose NOT to use this method as the Pi4 8Gb is out of stock at Element14 until February 2022!

However, if you are interested in push testing your pi – you could try cpuburn.

Disclaimer: Check out the tool name before you try it.

Pi4 8Gb RAM – November 8 Bullseye release

Originally, I was going to test the Pi4 temperature with the different heatsink options by Sunday, November 7, but using such an old release was daunting. As it turned out, the next day, the October 30 image was released.

Heatsink with Dual Fans

The heatsink with dual fans was in the 25 dollar range at Adafruit, but I have a supplier who sent these to me for less than 10 dollars each. The dual fans option was nice. I was really hoping for great results – Of course, I had to use 12 screws instead of 4… but it seemed worth it.

2 fans… 2 GPIO pins – 5V and GND.

The heatsink with dual fans wasn’t just good, it was awesome!

Temperature Readings (Your Mileage May Vary: YMMV)

Idle flat: 50.1°

Idle side: 43.8° (after 20 minutes)

Running Process Flat: TBD

Highest Temperature: TBD Currently 50.1 idle

Lowest Temperature: 43.8° (idle side)

This particular model seemed to do better on the side. The temperature was higher than heat sink only.

Heatsink only

No Fans

The heatsink only option required 4 screws and was quickly set up. This options is simple and when you pick up the pi, there is no chance of accidentally hitting a moving fan.

Idle flat: 45.7°C

Idle side: 44.8°-48.2°C

12 hours idle side 51.1°C

Running Process Flat 49.1°C – 51.6°C

Highest Temperature: 51.6°C (running upgrade flat)

Lowest Temperature: 44.8°C (6 hours idle side)

The Bare Facts

Without any heatsink at all (not even those tiny ones), the pi4 reached a high temperature of 63.7 when running an upgrade. However, this is nowhere near the 80+ degrees reported in the early versions of pi4.

Idle flat: 46.7°C -50.1°C

Running Process Flat: 61.3° – 63.7°

Idle Flat after Process: 53°C – 55.5°C

Highest Temperature: 63.7°C (running upgrade flat)

Lowest Temperature: 46.7°C (8 hours idle flat)

Conclusion and Next Steps

There are many more tests that can be done by stress tests, running conditions and using a thermal camera. If I use my thermal camera from my pi4, will that impact results!

The Pi4 8Gb in this case, did not reach temperatures high enough to be overly concerned.

A tool or script for running temperature checks seems like a good idea for the community or the workplace. The data can be collected and analyzed over time. This makes sense.

Extra – Capture screenshots with simpleSCreenshOT

As a hobbyist I was interested to see scrot being used for screen captures on this version of the raspberry pi OS image – you can easily set a script to take automatic screen captures in the background.

  1. Add the CPU temperature to the panel.
  2. run scrot

Duration: Runs for duration indicated in script (default: for i in {1..360}

Default time for each capture in seconds:  Every 5 seconds.

Images directory: ~/Pictures

The images may need a different dir to push to. You may need to create a directory to place images (mkdir thisdir). You could even add some code for making a dir to the script.  Name the script.


for i in {1..360}; 

scrot -d 5 '%Y-%m-%d-%H:%M:%S.png' -e 'mv $f ~/Pictures/';


While I liked the performance of the heatsink only, the fan temperatures are close enough to enjoy this cool option also.

Works For Me!

works for me!