What does overclocking actually mean / what does it do?
The Raspberry Pi’s SoC, which includes the CPU, consists of many millions of transistors. These transistors need to be synchronized with each other, in order to be able to “move in unison”. A common clock speed is applied to this – the clock “ticks” are like commands to little soldiers: “move”, “hold”, “move”, etc. They mark the transition between operating states (for example individual commands being executed on the CPU). This is a gross oversimplification, to give you a rough idea of what is happening.
With overclocking, we ask these transistors to do their work in less time – to switch faster between the individual states. There are physical limits to this, since we’re talking about real atoms which have to perform the work for us.
Furthermore, as electric signals travel at finite speeds, synchronisation between transistors (or on a higher level, functional units) needs to happen across the SoC – if the clock speed is too fast, these signals can’t propagate properly, the individual functional units aren’t synchronized, the CPU crashes.
Imagine this as a very long trail of soldiers which are marching in a parade. If there are some in the back which march a bit faster, and they don’t get to synchronize, they will bump into the rows ahead of them eventually, disrupting the whole parade. Or if they march slower than the ones ahead, they will loose touch with their comrades – the whole parade will become chaotic. Therefore, a clock speed (marching speed) has to be found which works for all soldiers (all functional blocks).
In reality, this is a bit more complex, since functional blocks on the Raspberry Pi SoC are somewhat independent, and can even operate at their own clock speeds. There are further constraints, for example HDMI 4K output will require different speeds on the Pi 4, etc.
Which applications will benefit from overclocking?
Typical applications which require a lot of processing power usually include web-browsing, compiling, games.
How can I overclock my Raspberry Pi 4?
We have built an easy to use, free web-based tool to allow you to choose the right settings to overclock your Raspberry Pi 4:
In five easy steps (two are on your Raspberry Pi), you'll be able to overclock your Raspberry Pi 4, Pi 400 or Pi 3B. Head on over to our tool & try it now - looking forward to your feedback!
Max