What is overclocking?
Not all computers are created equal. You probably know the basics of what makes your computer tick: RAM, ROM, processors and graphics cards. It's a mix of those components (among other things) that determine how fast your computer runs. You might go in for a RAM upgrade or a new hard drive every few years to keep things running smoothly.
Central processing units (CPUs) have mostly hit a point where they're good enough for the average user's average tasks. But when it comes to overclocking, we're not talking about average users. We're talking about people who want to eke out every last drop of performance from their processor.
CPUs come from the factory with a set clock rate -- the number of operations per second it can comfortably perform under normal conditions. It's a proven, safe operating limit. Forcing your CPU to run faster than that clock rate can cause stability issues or even total failure. Get ready to live life on the edge, because overclocking is running your computer's CPU faster than that set speed. It's possible to manually increase the clock rate set by the manufacturer in some CPUs, speeding up your computer in the process.
Why isn't my computer that fast all the time?
The flipside of that is that CPUs come with set clock rates for a very good reason. The factory-set speed limit is usually how fast the CPU can run with garden variety cooling and power methods.
Asking your CPU to perform more operations per second than it's meant to means that it will draw more power and produce more heat -- both major concerns inside a PC tower.
It's also, strictly speaking, not something you're meant to do, so overclocking usually means voiding your computer's warranty. If you don't get up adequate supply for the new power demands or install new cooling systems to deal with the extra heat, you could even permanently damage your CPU.
Why do people do it?
Overclocking definitely falls into the enthusiast camp. The stability issues and specialist hardware required mean that it doesn't see much professional use.
For enthusiasts though, it's not about the performance boost itself. It's about chasing speeds. It's digital frontierism, testing components well outside of the recommended settings to push current tech further or jury-rig older tech to keep pace with the cutting edge.
There's even a competitive benchmarking scene, with overclockers competing to hit the fastest speeds in standard computer performance tests. This is the extreme far end of the spectrum, incorporating things like liquid nitrogen cooling systems, and keeping CPUs at -100 degrees Celsius (around -140 degrees Fahrenheit).
What do I need to overclock my computer?
You'll need to make sure your hardware is capable of handling it. The most important part of overclocking is to go slow, and make sure you're feeding your computer enough power and making sure it can deal with the heat.
Water cooling systems are far more efficient than the usual fan-based air cooling, and good air flow means that the heat won't be trapped inside your tower.
Overclocking also means going into your computer's BIOS -- the program the processor uses to start your computer -- to manually edit the clock rate and the voltage. Every BIOS will be different, so you'll need to do a bit of research about yours.
There's also a lot of testing small incremental increases to make sure everything is stable and your computer's internal temperature remains steady. There's no one switch to flip.