5 Cool Ways to Keep Your Overclocked Raspberry Pi 3 Chilled
Your Raspberry Pi can do so much, but it has its limits. But like any computer, those limits can be pushed, if you know what you’re doing.
Overclocking is a feature built into the Raspberry Pi, and once you’ve learnt how to overclock your Pi you’ll be doing it all the time. As with a desktop computer, pushing the processor in this way can be made even easier with cooling solutions.
Heat sinks, fans, and even liquid cooling are all options for the Raspberry Pi. The following ideas are specifically for the Raspberry Pi 3, but with some tweaking can be used on other models, including the Pi Zero.
Why Cool Your Raspberry Pi?
In most cases, you won’t need to worry about keeping your Raspberry Pi 3 cool. However, if you’re employing it as a Kodi media center or as a retro gaming center then there is a good chance that doing this will prove useful.
Heat is the enemy. When a processor gets busy, it gets warmer. This heat slows things down, leading to more processing… It’s a vicious circle. Reducing the heat produced by computers improves performance. This is why GPUs come with huge heat sinks and cooling fans attached, to draw the air away. It’s also why PC towers have inlet and outlet fans.
When it comes to the Raspberry Pi, the same rules apply. But be warned: while cooling your Raspberry Pi can help, there is a physical limit that will restrict what you can do with it. Even putting your Raspberry Pi in the freezer won’t help here.
1. Pi Heat Sinks
To get started with cooling your Raspberry Pi, you might consider attaching heatsinks. These are typically available in pairs, one for the System on a Chip (the Broadcom BCM2835 SoC, a stacked CPU, GPU, and RAM chip), and one for the LAN chip (which controls the Ethernet adapter).
Heat sinks for the Raspberry Pi usually have the thermal adhesive applied already. All you need to do is peel back the protective film, and attach to a clean CPU (use 91 % rubbing alcohol and a cotton wool bud to be sure).
In most cases, standard heat sinks can be purchased from Amazon. Several different types are available, but they’re all very similar. They’re also very affordable. If you have multiple Raspberry Pi’s it’s worth equipping them all with heat sinks.
2. Extreme Heat Sink
Using a heat sink is known as “passive cooling,” whereas this option is known as “extreme passive cooling.” The idea is to use a larger heat sink (perhaps pulled from a PC or GFX card) and mount it on the Pi’s SoC. Unfortunately, this isn’t simply a case of applying thermal paste and sticking the heat sink in place.
The Raspberry Pi has several components dotted around the SoC that have a higher profile. As such, you’ll either need a heatsink that is clear of these, or you’ll need to attach a carefully-sized piece of copper plate between the SoC and the heatsink.
We think the video above demonstrates this best, complete with a clear plastic shield to avoid shorts. Ultimately, the heat sink is secured in place not just with thermal paste, but also with a secondary piece of plastic (Perspex) which is then screwed into the Pi, and a bit of hot glue.
Watch to the end of the video where you can observe the (impressive) results of this extreme passive cooling.
3. Fit a Fan to Your Pi
The majority of heat sinks in desktop computers have a fan attached, and its especially true in laptops. Here, heat sinks draw heat from the CPU and GPU, thanks to one or more fans situated around the outside of the device, and not connected to the heatsinks. Microsoft’s Surface Pro tablets are particularly good examples of how passive cooling can be employed.
If you want something a bit more active, however, then it’s possible to connect a fan to your Raspberry Pi to keep the device cool. All you need is a suitable fan, which is connected to two GPIO pins for power.
Many suitable fans are available for the Raspberry Pi, which you’ll find online. However, you may prefer a case with the fan included.
4. Use Water Cooling
A fan is a great way to enhance cooling… but what about water? Of course, splashing some water on your Raspberry Pi will be dangerous, but water cooling has long been employed in hardcore gaming PCs. On a smaller scale, you can use it on your Raspberry Pi.
This video explains how:
Again, the results from this can be excellent. You’ll find a water cooling kit from ModMyPi.com, but a word of warning: take your time with this!
To be safe, put the kit together as far as you possibly can before bringing your Pi into the equation. If you were putting one together for a desktop PC, the sensible option would be to construct and run it, with water, before putting it anywhere near your precious computer. A Raspberry Pi may be a fraction of the price of a desktop gaming center, but the principle remains the same.
As for arranging your setup, consider how visually stunning a water cooled computer can be. Employing LEDs and colored tubes can result in a very striking Raspberry Pi!
5. Take the Plunge With Mineral Oil
Finally, we can go one further than water, and get rid of the fiddly cables and water cooling tubes. Instead, consider mineral oil cooling. The idea of this is to submerge your Pi into the oil, in a way that you simply couldn’t with water.
Because mineral oil is not conductive, and displaces air and water, there is no opportunity for electrical malfunction or shocks. However, there is still the potential for some peril here.
In this example, the Pi is suspended with fishing wire in a fish tank. Some LEDs are added, and the Pi is connected to the mains cable and HDMI cable as usual (some right-angle HDMI adapters may prove useful to you). The mineral oil is then added, the Pi submerged, and the computer booted up. All should be well, with the Pi’s temperature kept under control by the liquid.
However, small breaches in the rubber shielding on the cables can lead to the oil being drawn out of the tank. This is particularly a risk on the HDMI cable, as is the possibility of the oil breaking down the rubber around the cable. Keep an eye on this if you try mineral oil cooling.
How Do You Keep Your Pi Cool?
Standard operation of the Raspberry Pi probably won’t require any cooling. But it’s always a good idea to use the standard heat sinks. Your Pi’s case might not be as air-flow friendly as you think.
If you’re concerned about your cooling solution, then you can check the current temperature with a single terminal command:
If you’re trying any of these cooling solutions, however, a tool that pushes the CPU and measures the system temperature is more useful. The sysbench program is ideal for this.
Remember, there are five ways to cool an overclocked Raspberry Pi:
- Standard heat sink
- Custom-made big heat sink
- Fit a fan
- Reduce temperature with water cooling
- Suspend your Pi in mineral oil
How do you keep your Raspberry Pi cool? Just heat sinks, or do you have another method we haven’t covered here? Tell us below!