The Rapberry Pi is a great little device for building some sort of retro gaming computer. However, even with the quad-core power of the Pi 3, some emulators are a little sluggish and others are too slow to be playable.
Like other Rasberry Pi models the Pi 3 is overclockable, however it does run rather warm and overclocking can cause it to overheat. The key to overclocking the Pi3 is cooling and the scope of this project is to build a cooling system for the Pi3 and see how far it can be overclocked. Every ounce of horsepower gained from an overclock should help with the performance of the emulators.
There are other projects on the internet some of which include liquid cooling systems. I wanted to keep this project sensible and affordable and therefore opted for a heatsink and fan. If it's good enough to keep my PC processor cool then it should work well enough on a Pi.
Selecting a Heatsink & Fan
I have a large box of heatsinks of all kinds from TO220, DIP IC to large AMD CPU coolers. After much deliberation and trial and error it was decided to use a Zalman ultra quiet PC CPU cooler. These have a very large fan which rotate relatively slowly and create very little noise whilst still creating good airflow. These cooler's are designed for use on 125W desktop PC CPU's, so should perform very well on the tiny low power ARM based product fitted to the Pi. This range of ##### also have a narrowing base which would make it easier to fit onto the Pi without much modification. The fan is also large enough to blow air to the underside of the Pi cooling the memory. These types of cooler are fitted using a standard PC sprung loaded clip so a method of mounting would be required.
Now I had the plan and the parts it was time to build the prototype.
Step 1: Preparing the Pi.
Despite it's narrowing base and the extra copper shim (described later), the Zalman cooler still hits some of the Pi's components before reaching the CPU. Therefore the GPIO header must be removed. If connection to the GPIO pins is required then wires will have to be directly soldered to the GPIO pads. The simplest and safest way to remove the GPIO header is to break or pull off the plastic around the pins and then heat up each pin one at a time and pull out the pin with pliers. If required then the GPIO pads can then easily be de-soldered.