One of the most intimidating parts of a build is the power supply. Its just a jumble of similar looking cables and it’s not that easy to figure out what needs to go where. So, to help those of you a bit unsure, here is our Power Supply Guide. In this post, we will go into the info you will need for picking and installing a PSU. Of course, some sections will change slightly depending on your PSU, motherboard and what peripherals you need to power up. So, here is How to Install a Power Supply!

First, lets look at your power supply.

So, what kind of power supply do you have, or are looking at getting?

PSU Type

There are 3 different types of power supplies on the market. These are: fully-modular, semi-modular and non-modular. The difference between the three are how the cables are hooked up to it. They will all come with the same cables, however fully-modular will mean the cables come separately to the PSU itself. This means you can pick and choose what cables to install and you can leave out the ones you don’t need. Semi-modular is the half way point, so the core cables that everyone will need (e.g. CPU, 24 pin) will come pre-attached, but other cables (e.g. Molex) will come separately, so if you don’t need them you don’t need to attach them. As you can maybe guess, non-modular means EVERY cable under the sun will be less-than delicately shoved into the power supply. The main benefits of fully-modular vs non-modular, is of course, fully-modular just reduces the number of cables you may need to plug in. This does come at a price though, as fully-modular PSUs tend to be more expensive.

This is an example of a fully-modular PSU
PSU Efficiency

The second thing to consider, is its efficiency. Most power supplies come with a power efficiency rating that you will notice on the box. These are 80 Plus bronze, silver, gold, platinum and titanium.  Without going into overly complicated stuff, this refers to how efficiently your PSU will run under load. A more efficient PSU will mean you waste less power, and generate less heat. Overall, it’s definitely recommended to pick up a PSU that has the 80 Plus sticker on it. For most standard builds, anything between 80 plus bronze and 80 plus gold will be perfectly fine. The platinum and titanium range (which tend to be the most expensive too) are usually more designed for higher end builds.

source: Velocity Micro
PSU Wattage

The final thing to consider, is of course, your wattage. Power supplies for PCs can come in a range from 200W all the way up to 1800W. The most common wattage you tend to see on the market though are: 550W, 650W, 750W and 1050W. So, does that mean the biggest number is always the best? No, not necessarily! Popping your planned PC parts into a program like PC part picker will calculate the estimated wattage for your PC. Picking a PSU of a higher wattage than you need won’t make your PC blow up or anything, however there is really no point in using a 1050W PSU for a PC that only needs around 400W of power. In that instance, you’re far better off either going with a 550W or 650W PSU.

On the side of this semi-modular PSU, you can see it’s wattage, 750W

Ok, so now How to Install a Power Supply!

The first thing I always recommend to do for any install, is take everything out of the box and lay it all out flat. Having a good look at the items you need will make everything much easier. Quickly familiarize yourself with the cables, taking note of how many pins they have and any labelling.

Motherboard Cable

Starting off with the chunkiest cable, locate your 24-pin cable. This is your motherboard connector cable and powers up your entire motherboard.  Some older motherboards only use 20 pins, but regardless it will still be obvious which one you need.

For fully-modular users, you are going to want to locate the 20-pin socket on the PSU. Check out the 2 ends of the cable, as one will split in 2 and the other side won’t. The side that splits is the side that will go into the PSU. Split it in two, and plug the longer header into the 20-pin socket, and the smaller header into the 4-pin socket below as marked.

The other side of this you plug this into the matching 24-pin socket on your board. This is almost always located to the right of the board and trust me, it’s a super obvious socket. I assure you, you will find it easily.

CPU Cable

For fully-modular users, you want to find the cable marked CPU. The side that has the words CPU on it, is plugged into the corresponding CPU labelled socket in the PSU.

On your board, the CPU socket is almost always tucked into the top left of your board. Be wary though, sometimes fans or radiators can make it hard to get to this spot. So, be prepared to temporarily move some things around to reach it if you have installed everything else already. The motherboard side of the cable also splits down the middle, so if you have a smaller board you might only need 4 pins.

PCIe Cable

Your PSU will often come with a few PCIe cables, and they all work the same. If you are running fully modular, pick one of them and simply plug it into the PCIe socket which is just beside the CPU socket. You will want to plug in the side that doesn’t have the little split off cable, as that side goes into your GPU eventually. Most GPU’s will only require one PCIe cable, however if yours requires two, simply plug  another PCIe cable into a PCIe socket.

This cable will power your graphics card, so simply thread the cable around to your GPU and plug it in. It may take a big of maneuvering to get it to cooperate (I always have a hard time getting the little split off section to plug in). So, don’t stress if this takes a little while, you’ll get there.

SATA Cables

Your SATA cables will stand out too as these cables look so different to everything else. These will power your storage such as your SSD or HDD.

For those of you who have to plug this cable in, you will now be using the last few slots labelled “peripheral”. It’s very obvious which side to put into the PSU, trust me.

The other sides will plug into your storage, whether its an HDD or SSD. For a look at how to install these, check out our video on it here.

Molex Cables

You might not have or need to use these, but because so many of our products do I figured it was worth mentioning.

Molex cables look somewhat similar to SATA cables in that they are long and look nothing like the motherboard cables. You can tell them apart from SATA cables as Molex cables have thicker, silver pins inside. You also plug this cable into a “peripheral” spot in your PSU.

The other end of the Molex cables can plug into all sort of peripherals, including powering our fans. These are notoriously hard to connect up properly though, due to the pins moving around a lot. So, this may take a bit of pulling the cable back out and trying again before it sits correctly. All I can say is, good luck cos with these you’ll probably need it.

And now you’re done!

Congratulations, you now know How to Install a Power Supply! I hope your power supply treats you well for years and years… mainly because replacing it can be annoying.

If you have any questions or tips you’d like to share on How to Install a Power Supply, feel free to comment them below to help out any other builders out there!

Also, remember to check out our other How-To posts on the blog, HERE!