Raspberry Pi Cooling - superjamie/lazyweb GitHub Wiki

Most people do not need additional cooling.

If your Pi is sitting there idle, as a personal desktop/server, or playing games, you probably don't need to worry about it.

Consider additional cooling if you're overclocking, running all cores at 100% usage, or storing the Pi in a very hot cramped environment.

Heatsinks and Fans

The little 15x15x4mm heatsinks aluminium/copper heatsinks commonly seen in most kits barely do anything, a few degrees at most, they are a waste of time.

Some of them even come with regular double sided tape which probably insulates and keeps heat in instead of conducts heat away!

This guy did a good series of heatsink tests from an 85C baseline:

• https://www.youtube.com/watch?v=e6okZKRwnTQ - Tiny heatsink = 80C
• https://www.youtube.com/watch?v=5Ud-grj4Zl0 - Tiny heatsink and fan = 60C
• https://www.youtube.com/watch?v=1AYGnw6MwFM0 - Giant heatsink = 50C
• https://www.youtube.com/watch?v=WfQMLInuwws - Giant heatsink and fan = 35C

So, the bigger the passive heatsink the better. A fan also helps.

I have fitted several Pi models with 25x25x15mm heatsinks using good 3M conducive double sided adhesive. They juuust fit most cases with a flat top. They end up the same height as the USB ports.

Fan Power

You can power a small 5V fan off the 5V GPIO pin. A 40mm fan should be enough, but you could go as small as 20mm. Try to get a quiet fan. Just moving the hot air away is probably enough, you don't need a noisy jet turbine.

The 5V GPIO pins are passed through directly from the microUSB power supply connector, so you can drive a fan off the 5V pin safely. A fan will typically draw around 200mA. Most fans are rated in watts and Watts / Volts = Amps, so say 0.5W / 5V = 0.2A (200mA).

The max current able to be drawn through the entire 5V line is covered at Raspberry Pi Power.

Do not use the 3.3v or other GPIO pins to power high current devices!!! The rest of the GPIO pins pass through the SoC and can only supply very limited current. The exact number seems unknown, but a safe max seems 50mA over all GPIO pins, and max 16mA per pin.

References:

• http://raspberrypi.stackexchange.com/questions/9298/what-is-the-maximum-current-the-gpio-pins-can-output
• https://raspberrypi.stackexchange.com/questions/51615/raspberry-pi-power-limitations
• http://elinux.org/RPi_Low-level_peripherals#Power_pins
• https://www.raspberrypi.org/forums/viewtopic.php?f=44&t=12498

Thermal Test

• CPUBurn-A53

wget https://raw.githubusercontent.com/ssvb/cpuburn-arm/master/cpuburn-a53.S
gcc -o cpuburn-a53 cpuburn-a53.S
while true; do vcgencmd measure_clock arm; vcgencmd measure_temp; sleep 10; done& ./cpuburn-a53

• Linpack

sudo apt-get install libmpich-dev
wget http://web.eece.maine.edu/~vweaver/junk/pi3_hpl.tar.gz
tar -xvzf pi3_hpl.tar.gz
chmod +x xhpl
./xhpl