CPU Power Limits – How to Reduce CPU Temperatures in a Fanless PC

One of the questions that I get asked most often is how do you lower the CPU’s temperature in a fanless PC. There are multiple ways to do this, other than simply using a CPU with a lower TDP. One method in particular though is very simple and effective, without sacrificing a huge amount of performance. One method is to under-clock the CPU, but this method is not the most efficient. Directly limiting CPU frequencies will also prevent any boost advantages, and will sacrifice more performance than necessary. Another method is to under-volt the CPU. This method can be effective while minimizing performance loss, but it can also affect stability and cause unusual side effects that limit performance more than expected. I wouldn’t recommend under-volting to most people because finding a sweet spot can be complex and time consuming. It can be worth it though if you like tweaking and you know what you are doing. The one method that I would recommend to just about anyone is to limit CPU power directly. The amount of power running through a CPU, measured in watts, can be directly correlated with the CPU’s temperature. By limiting power to the CPU, we are not directly limiting frequencies, so the PC can still take advantage of boost frequencies for one or two cores, when it fits within the power limits chosen. We are also not affecting system stability by not altering voltages. Single threaded performance is generally not greatly affected by limiting power, only multi-threaded...