Modern components, notably processors, GPU's, RAM, and some elements on
the motherboard, are very small and draw a lot of power. A small area doing
a lot of work with a lot of power leads to high temperatures. Various factors
can cause electronic parts to break down over time and all of these factors
are exacerbated by heat. Very high temperatures can burn out chips almost
instantly, while running hot can shorten the useful life of a part, so the cooler
we can make these parts, the better.
If you are not going to overclock your system, stock air cooling, when paired
with a good case with adequate fans, should be enough to keep your system cool.
If you want a quiet computer then components designed for passive (fanless)
cooling can be paired with very low noise case fans (or a well-vented case). In
general, high-end parts will require more attention to cooling.
To keep your system at a proper operating temperature, you can monitor
vital components with software (which usually comes with your motherboard).
If you are seeing high temps, make sure the interior of your case is dust free, and
remember that most cooling solutions can not reduce the temperature of your
computer parts below room temperature. Of course, unless you happen to have
your computer outdoors in a climate such as the Sahara, room temperature will
be well within the thermal limits of any component on your computer.
Which brings us to overclocking. It’s specialty cooling solutions that make
overclocking possible, a processor that might run stable at a maximum of 3.3
GHz at 60C could hit speeds as high as 5 GHz with specialized cooling systems.
A sensible person wanting a 20% overclock could add a special fan/heatsink to
his CPU and some extra case fans. An enthusiast seeking a major overclock
might go with a water-cooling solution for the CPU and GPU and sometimes
other chips. The real fanatics have been known to use liquid nitrogen or total
immersion in pure water or oil. You should not try any of the more extreme
solutions unless you ’really’ know what you are doing.