The power supply unit (PSU) is an essential component in a computer system, as it supplies power to all your PC hardware, including the motherboard, processor, and graphics card. Installing a PSU can be intimidating due to the numerous cables it comes with, but this guide will walk you through the process step by step. The power supply is one of the last things you should install in your PC case, alongside the graphics card. That said, whether you are here to learn how to install a PSU for the first time or perform an upgrade in your existing build, let’s look at how to install the power supply in your PC.
In this guide, we will also help you install the various component cables provided with your power supply, which is something many first-time PC builders find tedious. By the end of this article, you will understand where each power cable plugs into the motherboard. This is a step-by-step guide on how to install the power supply (PSU) inside your PC case.
Check PSU Wattage RatingChecking for an 80 Plus RatingCheck Available Power Supply Connectors
Gather the Necessary ToolsInstall Core Components in PC CasePlug in the PSU Power Connectors
Things to Consider Before Buying a PSU
Check PSU Wattage Rating
Before installing your power supply, it is important to ensure that it is compatible with the rest of your computer system. You can do this by calculating the total wattage consumption of all your components and comparing it to the PSU total’s wattage. It is generally recommended to buy a PSU where the total wattage is at least 150-200W higher than the calculated consumption to allow for some headroom in case of power spikes.
It is important to be cautious when purchasing a power supply unit (PSU) with a high wattage rating but a low price. It may not deliver the advertised wattage and could end up damaging your PC components. so the best way to ensure that you are getting a good-quality PSU is to check for an 80 Plus rating.
For those unaware, the 80 Plus system rates PSUs based on their quality and efficiency, certifying them into tiers, including Bronze, Silver, Gold, and Platinum, among others. Since the power supply is an important component, you must never cheap out and get the best one for your build.
Your power supply needs to have sufficient connectors for your CPU and GPU. Some motherboards take dual CPU connectors and newer graphics cards like the GeForce RTX 4090 GPU require at least three PCIe 8-pin connectors. Now, some high-wattage PSUs (including a 1,000W unit) may not have enough connectors for all of your components at times. So ensure your components are compatible with each other, and that you have the required connectors on your selected PSU.
Gather the Necessary Tools
Before building your PC, gather all your installation materials and tools. In this case, you will need a Philips Head screwdriver. Plus, ensure the workplace is clean and static-free (avoid building on top of a carpeted floor). Also, wear an anti-static bracelet during installation to prevent electrostatic damage.
Before installing the power supply (PSU), make sure to install the motherboard in your PC case, along with all the core components such as the CPU (possibly the Intel Core i9-13900K), memory (RAM), and storage drives. You must also have your hard disk drives (HDD) and 2.5-inch SATA SSDs pre-installed in your case before the PSU installation.
Plug in the PSU Power Connectors
In case you have a semi-modular or fully modular PSU, plug in all the necessary cables before installing it in your computer case. If you have a standard, non-modular power supply, you can skip this step. Otherwise, make sure the following cables are plugged in before placing the PSU inside the case:
Note: If you have a non-modular PSU, you may continue with the installation guide and not use the extra cables that aren’t required to power any components.
Once you are ready with your power supply and the installation tools, the first step requires you to figure out where to install the PSU. In most PC cases these days, the power supply shroud a few PC cases, the power supply shroud is usually positioned at the bottom, while in some cases, it is positioned at the top. You also need to ensure the power supply fan has proper ventilation in its final orientation.
Now, place the power supply in its designated location, making sure the power supply fan aligns with the ventilation cutout in the case. In most instances, you have to simply place the PSU with its fan facing downwards.
When positioned correctly, proceed to screw in the power supply in the PC case. Make sure to tighten the screws diagonally so as to reduce stress on one side of the component.
Connect Power Supply to Motherboard Components
Once you have successfully installed the power supply in the case, it’s time for the most important task – connecting the PSU cables to the required connectors on the motherboard. Let’s learn how to do that efficiently:
Next, start by plugging in the 24-pin motherboard power cable and 8-pin CPU power connectors into the corresponding female connectors. When you push the cable in, do it firmly with your whole hand to ensure the connectors are installed perfectly. The highlighted notch on the cable and the motherboard’s side should both snap into place. The same goes for the CPU power connector.
Now, install the graphics card on your motherboard and screw it on the computer case. After that, locate the power connectors present on your GPU. Proceed to plug in the 8-pin or 6-pin PCIe power connectors required to run your graphics card. The orientation for plugging in the PCIe 8-pin power cable can change depending on the GPU. You must look out for the notches where the power connector clips in. They are also on the opposite side sometimes.
Next, plug the SATA power connectors into your hard drive or SSD after aligning them. Also, plug in the required SATA or MOLEX power connectors for the remaining peripherals, such as your PC case’s RGB lighting or fans.
Well, you have successfully installed the power supply in your PC case and its various power cables on your motherboard. But there are a few additional tasks you need to do next. So get some zip ties and use them to ensure proper cable management and optimal performance. Securing the cables neatly in place can help improve airflow and give your PC a clean, organized look.
Now, you can proceed to finish the rest of the PC build if there’s still something left to install. After that, install the side panels in your PC case and screw them back in place. Lastly, connect the main power cable to the back of the power supply and connect its plug to an outlet. If you get a 1,300W+ PSU, you may need to plug it into a 16A socket. So, check with an electrician as your PSU might work better on a higher-amperage electrical socket.
For those wondering, what do the markings on the power supply switch mean? Here, a line (-) represents the ON state, and the circle (O) represents the OFF state.
- And that’s it! We hope you have carefully installed the power supply and turned on your new computer. As long as you have installed the rest of your components correctly, and connected the power switch to the motherboard, the PC should turn on by pressing the power button on your PC case.
Install Power Supply in Your Computer Case
To turn your PC on, flip the PSU switch to the “ON” state, represented by the line symbol. Then, press the power button on your case to turn on the computer. The circle mark on the PSU button means it is in an ‘OFF’ state. Remember to never flip the switch while the PC is running, but you can do so to force shut down when needed by holding down the power button.
Yes, you can easily swap out an older PSU for a new one. You must remove the existing PSU first and make a mental note of where the previous connectors were installed. Then, follow our guide to install a new power supply in its place.
The 16A socket is only necessary for high-end power supplies. Behind the power plug of the PSU, it mentions what amperage it needs to function properly. Then, you can accordingly decide whether to use a 16A socket or not.
It’s not absolutely necessary to connect your PSU to a UPS, as the power supply comes with many protection mechanisms in case of power loss. However, if you are doing important work on your computer, having a UPS will ensure you don’t lose out on the data. PC shutdowns due to power cuts may also suffer from storage corruption. So, most people should invest in a UPS to avoid losing data.
The orientation of the power supply depends on where the ventilation holes are present in your case’s PSU chamber/shroud. Simply ensure that the fan is facing the side where it can pull fresh air in to cool the power supply unit.
