IN SHORT: What is PSU/ SMPS and Why Do I Need it?

What is a PSU/ SMPS?

A PSU can be expanded as Power Supply Unit and as the name suggests, it is the Holy Grail that supplies your computer with the strength to stand. Okay, maybe it is not the Holy Grail, but it’s definitely a major component which is often taken for granted.

To put it simply, the PSU/ SMPS is the unit that converts your AC current (Alternating Current and yes, they call it AC current, we know it sounds redundant!) into a DC current (Direct current) to power the components of your computer.

Why Can’t I Just Use AC Current for my Components Directly?

The need to convert an AC current into DC current stems from the fact that computer components such as the CPU, RAM, Motherboard, GPU and the rest are built with careful precision to utilize precise voltage levels. Anything beyond the maximum will easily fry the component or leave it crippled.

What is PSU

An Alternating Current alternates between positive and negative as shown in the graph above and is not suitable for components that require a steady positive current, which is where the DC current comes in. Take a look at the graph below and you will understand that the AC voltage is linear and does not alternate which provides the components a steady voltage to work with.

What is PSU 2

Generally, no one goes as far as to ask this question because the average consumer either doesn’t care or already knows about it and in case you didn’t, don’t worry now you do!

PSU and Wattage!

The PSU sits in between your AC current and the computer components and converts the AC current into DC current so that your computer can function normally.

PSUs come in a range of wattage including 300, 430, 450, 1200, etc. and the right one for you always depends on the type of components you are using for you CPU, GPU, RAM, etc. Some CPUs/ GPUs use less wattage while the others use a lot of wattage, so it is important to list out your power requirements before fetching a PSU.

Ideally, a PSU is at its best when running on 55-65% load. For example: A system that requires 300 watt power would do great with a 500 watt PSU. While a 350 watt PSU should be adequate, it will run hotter and noisier than the 500 wattage.

It is also extremely important to buy a branded PSU/ SMPS which is received well by the market rather than generic ones, Click here to learn about the different certification standards for a Power Supply Unit and why you should never cheap out on them with generic ones.