How to choose a PC Power Supply

A quick buying guide for power supplies

Before we choose a PSU and actually buy it, there are some things to consider. It’s not advisable to just rush into something that can be so important for the further building of our PC. That’s why we always need to know certain things that help us get a power supply that we want and actually need.

First of all, we need to decide whether we want a modular power supply. We need to get our facts straight on an 80 Plus Rating. Furthermore, it’s always good to know what a +12V Rail is, and finally how many watts we need for our gaming PC.

If you’re in any kind of doubt regarding the purchase of a power supply, please feel free to post your questions in the comment section below. We will be more than eager to help since we understand that the whole process can be both confusing and tiring.

Deciding on a modular power supply

The main aspect when considering to either go with a modular or non-modular power supply is practicality.

Modular power supplies are much easier to work with. However, they cost more. So especially if you’re on a tighter budget, you will have to choose between going with the easier option and paying more or going with the other one and saving some money.

Non-modular power supplies are great and all, however, we always had to deal with a bunch of cables. Some of them were completely unnecessary for us. We usually like our gaming space neat and clean, so we really had a hard time hiding all that cable clutter.

However, if when we saved money by buying a non-modular power supply, we were able to buy a better video card, and thus compensate. For the price of cable clutters we got a much better in-game performance.

So all in all, when we decided between a modular and non-modular power supply, we had to choose whether we’ll go for the aesthetics or performance. We obviously chose performance. However, that also depends on your personal budget and the PC build that you’re trying to put together.

Why is the +12V Rail important?

The main function of +12V Rail is to deliver raw power to GPU and CPU. As we are all aware of, those two are the components that require the most power in a configuration. So basically, the +12V Rail dictates the type of build that particular power supply can handle.

+12V Rail Power Supply

+12V Rail is also important because we use it to compare the price of power supplies in the same price range. It can also help to see through some fraudulent information that some manufacturers or vendors may display. Let’s say that we were looking to buy a power supply that has 850W and +12V Rail of 28A. But then we saw that all other 850W power supplies in the same price range have +12V Rail of 60A. Thus we concluded that the manufacturer of the first-mentioned PSU is giving wrong information and thus misleading us into buying something that isn’t as powerful as it’s stated.

There is one thing that we all must understand when it comes to graphics cards. Manufacturers usually tend to put minimum power supply requirements that are actually higher than the real minimum. Why is that? Well, the practice showed that there are power supplies manufacturers out there that put higher wattage capacities than what those power supplies can actually deliver. Thus, we always use +12V Rail of a certain power supply to determine what type of graphics cards that power supply will be able to support.

We always use this list in order to determine the minimum +12V Rail rating for the graphics card that we’re interested in. It is really helpful as it shows whether the two will actually be compatible and work flawlessly.

Understanding the 80 Plus rating

Power supply manufacturers use the 80 Plus Rating certification as a voluntary program in order to test and determine the performance of their power supplies. So basically, every manufacturer that wants to have an 80 Plus rating on their product will send their units to certain independent labs that will put those PSUs to the test.

So how do they figure out how a certain power supply will perform? Simply put, they have to find out how much power a PSU loses while converting AC power to DC. Hence, the more power a power supply loses, the worse grade it will get.

They also test how a power supply behaves under different loads. Logically, the higher the load that we put on a power supply, the worse it will perform. However, there are power supplies out there that are simply amazing at sustaining really high loads. The amount of power that they lose during the process comes to a bare minimum. Hence, all those units earn special 80 Plus ratings like Platinum, Gold, and Titanium.

What can we learn from an 80 Plus rating?

Basically, an 80 Plus Rating shows us the bare efficiency of a certain power supply. By understanding all of the aforementioned, we can know what to expect from a certain power supply when it comes to performance. However, we shouldn’t rely only on that, especially if the power supply in question is rated Bronze or Standard. Every rating above that surely indicates that we will get more than a solid performance.

80 Plus Rating PSU efficiency
IMAGE: By MSI Global

When we wanted to build a budget configuration, we were mainly stuck with power supplies that were rated Bronze. We needed to choose carefully between such power supplies, simply because there are ones that are really good and others that are not so much for the price in question.

The Corsair CXM series are great Bronze-rated PSUs. They are featured on our PSU tier list alongside others that we really find to be quite satisfying. Finally, even though the 80 Plus Rating can tell us a lot about the overall performance of a certain power supply, we should never rely solely on that when we’re buying one.

Watts needed for a smooth gaming experience

It is the main thing that confuses us, especially if we’re building a PC for the first time. Simply put, a PC configuration that incorporates a single video card will require a power supply in the 400W–600W range. That’s for the most basic setup.

The component that draws the most power is the graphics card. Hence, alongside with other power-hungry components, it dictates what type of power supply we’ll need. The more higher-end graphics card we plan to put into our configuration, the more powerful PSU we will need.

When buying a power supply, we should also be very careful. Many manufacturers tend to list 800W on their units when in reality they are no more than a simple 500W power supply. Those manufacturers do that by cheating when they’re testing out the power supplies in question. So it’s always good to double-check and make sure to avoid units with such fraudulent information.

In the end, we should always be aware that looking for a power supply just by the listed wattage can have its shortcomings. As we saw, some of that information may be fraudulent, so always make sure to check other aspects too, like +12V Rail and 80 Plus Rating.