Power Supply Unit (PSU)
Got your CPU, RAM, Motherboard, GFX card, sound card and cooling all in place. Now, how to power them all...
The solution is the PSU, or Power Supply Unit. As the name implies, it supplies power to the rest of the components via MOLEX connectors on the motherboard. Now, most people think of power as Voltage, but a computer will often use very little voltage and use lots of Power instead. Power is essentially how much work the electricity does, and is measured in Watts (W). For those interested, Power is Current (represented by I) multiplied by Voltage (V)
The solution is the PSU, or Power Supply Unit. As the name implies, it supplies power to the rest of the components via MOLEX connectors on the motherboard. Now, most people think of power as Voltage, but a computer will often use very little voltage and use lots of Power instead. Power is essentially how much work the electricity does, and is measured in Watts (W). For those interested, Power is Current (represented by I) multiplied by Voltage (V)
![Picture](/uploads/2/3/8/4/23842263/1135231.png)
To the left is a standard, high power PSU. On the top a fan for cooling the circuit (a little more in a minute), on the left side are the various output connectors and on the back (not visible) is the mains input and master switch.
A PSU works by converting the 220V AC electricity from the mains (totally useless for computers) to +5V or +12V DC electricity (exactly what the computer needs) via an EPC (Electrical Power Converter) and then runs it through to the computer.
A PSU works by converting the 220V AC electricity from the mains (totally useless for computers) to +5V or +12V DC electricity (exactly what the computer needs) via an EPC (Electrical Power Converter) and then runs it through to the computer.
Generally speaking, the PSU won't just pump the system full of power, but will work with the OS to give as much as is needed at the time. However, the efficiency of the PSU must be taken into account. Having a PSU that says it can supply 1200W at 50% efficiency is terrible, and will not only waste 50% of the electricity that's supplied to it, turning it into heat, but chances are it will only supply 600W of energy at any one time.