The power supply unit (PSU) is one of the most important components in your computer. The CPU may be its “brain,” but the power supply is the heart. We will discuss what are the most important things to keep in mind when choosing a power supply for your PC. Is it wattage, efficiency, or a few other points?
- Why is Choosing a Power Supply Unit Important
- 1. Wattage: how much do you need?
- 2. Efficiency: the higher the better
- 3. Size: depend on your case
- 4. Connector Types: the more the merrier
- 5. Case Temperature: higher is not always better
- 6. Noiselessness: keep the volume down
- 7. Lifespan: 100000 and above
- 8. Cost
- 9. Brand: why is it important?
- 10. Miscellaneous
Why is Choosing a Power Supply Unit Important
The power supply isn’t the first thing that comes to our mind when we’re looking to upgrade our desktop PC or build a custom PC unit. For budget-conscious users, meeting wattage requirements is often seen as sufficient. Many of us give little consideration to how power is distributed.
The superstars of PC specs – the CPU and GPU – usually occupy our mindshare. However, a PSU is actually the most crucial component in a desktop PC. Without a power supply to provide continuous electricity to the motherboard and other components, your PC would instantly fail.
Apart from supplying power, the PSU converts alternating current (AC) from a wall outlet into the direct current (DC) for your device. In addition, it’s the PSU fans that keep the tiny circuits on your computer operating at optimal temperatures, controlling the noise output.
Related: as laptops have an external power source, they have fewer issues compared to a desktop PC, such as not sleeping when the lid is closed.
How to Choose a Power Supply for PC
When choosing a power supply unit (PSU) for your computer, there are several factors to consider. Before purchasing a unit, take a look at the packaging or check the specifications online. You can also find most of this information on the “PSU label,” a sticker on the power supply hardware unit.
1. Wattage: how much do you need?
Wattage refers to the maximum amount of power the PSU will consume from your wall outlet and make it available to your PC components. In order to calculate the wattage of your components, we recommend PC Part Picker as it’s very easy to use. Just drag the wattage scales to get precise search results.
Many users go for higher wattage, such as 800-1200 W which can be an overkill unless you’re a gamer. That can also rack up your utility bills. If you’re a light user, you can go as low as 200 W. Whichever wattage you choose on this website, you will find direct purchase options on Amazon.
You can also use Newegg Power Supply Calculator. Just enter your CPU, GPU, and motherboard details to get a recommendation. Using a power supply that’s “just enough” can cause it unnecessary stress and could lead to PSU failure. As a general rule of thumb, you want a power supply that has at least a hundred, preferably a couple hundred, watts above what your components will use.
FYI: as a general rule, gaming PCs have higher power requirements. They are more resource-intensive than ordinary desktop workstations.
2. Efficiency: the higher the better
Closely related to wattage, efficiency rating tells you how efficient the power supply is with its energy consumption. The higher the efficiency, the higher the quality of the power supply and the less power it’ll waste. This is a factor that can reduce your electricity bills and take care of PC overheating issues.
The efficiency rating value is given in percentage, and there are various tiers to consider. For example, the Redragon PSU has an 80 Plus Gold certification. Currently, the most common rating system used by manufacturers is the 80 Plus rating. Just look for one of these stickers on your PSU to find out its efficiency.
- 80 Plus offers, well, 80% efficiency.
- 80 Plus Bronze offers 82% – 85% efficiency.
- 80 Plus Silver offers 85% to 89% efficiency.
- 80 Plus Gold offers 87% to 92% efficiency.
- 80 Plus Platinum offers 89% to 94% efficiency.
- 80 Plus Titanium offers 90 to a whopping 96% efficiency.
Obviously, the more efficient the power supply is, the more expensive it is. You should target at least an 80 Plus Gold PSU if you have the budget.
Besides 80 Plus, newer efficiency standards are coming up that have stricter requirements. Cybenetics and PPLP (PSU Performance Level Plan) are two such rating systems that are now being used by several manufacturers. They also use a similar hierarchy but account for the new ATX 3.0 power supplies in the market.
3. Size: depend on your case
Nowadays, PC casings are getting smaller and smaller. When choosing a power unit for your PC, you’d want one that can comfortably accommodate in your casing. To find the right size, keep an eye for specifications like ATX, which refers to maximum dimensions of 150 x 86 x 140 mm.
Currently, ATX 3.0 is the form factor most PSUs follow. You can also go for a mini or micro ATX, which are smaller than a regular ATX, like this lightweight PSU by Apervia for small and compact PCs.
Related: whether it’s a mini-ATX or E-ATX, we have explained all the motherboard sizes you need to consider.
4. Connector Types: the more the merrier
Closely related to size, there are various types of connectors that link to the power supply. Knowing the connector types supported on your PSU will help avoid any incompatibility with the PC casing. You can find the connector type details within the PSU specifications.
For starters, a 24-pin ATX connector is fairly standard, along with a PCIe connector which is used to power on the graphics card. An example is this 750 W PSU which comes with standard 24-pin ATX, PCIe, 12 V CPU connectors, and SATA connector ports for connecting hard drives.
5. Case Temperature: higher is not always better
The case temperature that your PSU can tolerate is an important factor in ensuring performance and stability. Of course, it depends on your ambient room temperature, and the PSU is rated for a given temperature. While 10 to 40 degrees Celsius is a fairly standard rating, there are many PSUs that are rated much higher (these ratings are not given in Fahrenheit, even within the U.S.)
The upper end of case temperature tolerance can go all the way to 70 to 80 degrees Celsius, but that’s costlier. For the most part, you needn’t go any higher than a temperature rating of 50 degrees Celsius, as with this Cooler Master Gold certified 850 W PSU.
Related: you should also learn how to check the CPU temperature on your PC.
6. Noiselessness: keep the volume down
A noisy fan is the biggest sign of trouble in any computer, and you want to mitigate the issue ahead of time. While choosing a latest power supply, users are giving huge consideration to the noiseless aspect of the PSU fans. The above Cooler Master PSU, while managing a large range of temperature, also has a semi-fanless operation with extremely low RPM.
When purchasing a PSU, keep an eye out on specifications such as “zero RPM,” or “zero fan mode.” Some of these units also have noiselessness specified in terms of decibels.
Related: did you know a simple thing such as shutting down your computer can play a role in increasing your PC’s lifespan.
7. Lifespan: 100000 and above
Of course, PSUs degrade over time. They can lead to slower performance or failures which can add to your PC investment expenses. To mitigate this, purchase a PSU with a higher lifespan rating. It is indicated in terms of mean time between failures (MTBF) which is usually at 100000 hours and above.
A better way to get proper lifespan is to look for the right amount of warranty period. For example, this 1200 W unit by NZXT has a 10-year manufacturer warranty.
8. Cost
When purchasing or upgrading a PC, power supply specifications don’t figure very high. As a result, people aren’t willing to pay much more. Personally, as a non-gamer I wouldn’t spend more than $50 on a PSU. It’s easily possible to get an 80 Plus Gold standard unit at this rate.
However, if you’re a gamer or into heavy video editing, you need a more resilient PSU which can tolerate higher temperatures. While the exact cost you incur depends on your individual preference, you can find good power supply devices in the range of $100.
9. Brand: why is it important?
This is actually super important: you want to buy PSUs from only the most reputable brands. You should never put your PC at risk by using an off-brand, no-name power supply. Trusted brands would ensure they honor their manufacturer warranties which is a great assurance in case you encounter a hardware failure.
The brands generally considered to be the best are Corsair, Redragon, Apervia and Thermaltake. Aside from them, NZXT, XFX and Cooler Master are also notable for making good power supplies, as well as EVGA (who traditionally only deal in Nvidia graphics cards).
10. Miscellaneous
Last but not least, before you choose your ideal power supply for your PC, take stock of one or more of these extra criteria.
- Voltage: PSUs are designed depending on the country you’re in. Whether it’s 110 V in the U.S. or 220 V in Europe, you need to look for the correct voltage rating.
- Protection: a PSU protects your computer from voltage fluctuation and short circuits. Look for OVP (Over Voltage Protection), UVP (Undervolt Protection), SCP (Short circuit protection), and other such labels.
- Standby compatible: your PSU should be able to load the system instantaneously from several hours of idle time.
- Modularity: Basically, a power supply’s modularity determines how many cables come hooked into it when you buy it. If you can go for a fully modular PSU, it will solve a lot of your connectivity problems. But a semi-modular PSU can also serve your purpose well.
- Cooling method: different PSUs have different cooling methods such as air cooling, liquid cooling, magnetic cooling.
Related: find out what is PC liquid cooling and how it can help your computer.
Power supplies are delicate, sometimes dangerous, pieces of hardware. We have seen how to choose the proper power supply for your PC. While you’re at it, find out how to measure your PC’s power consumption.
Image Credit: Unsplash. All screenshots by Sayak Boral.
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