Article updated 13th October 2022
When it comes to building a gaming PC, a lot of emphasis is put on CPUs, RAM, GPUs, and other components, while not a lot of consideration is often given to power supply units.
The power supply unit, or PSU, is one of the most crucial components of your PC. It will power every other component necessary for a beast of a gaming rig, and if you skimp out on a good PSU it could cost you the whole PC.
What to look out for when choosing a PSU?
If you’re building your own gaming PC or upgrading your system to manage next generation hardware like Raptor Lake or the beastly RTX 4090, choosing an appropriate power supply should be one of your priorities.
It is best to avoid generic PSUs, that is to say - unbranded PSUs. In addition to being prone to substandard manufacture and quality, their manufacturers often do not offer any warranty or support than the bare minimum. If anything goes wrong, you’d have to get another PSU, increasing cost and maintenance. And that’s assuming that when your PSU went down, it didn’t take the rest of your PC components down with it. A PSU failure can be catastrophic for other hardware at best, and a potential fire hazard at worst.
Instead, look for reputable manufacturers, and those that offer warranty and support for their PSU units. Depending on the specification of your gaming PC, the optimal power supply will vary. Most desktop and gaming computers use the standard ATX specifications, though SFX PSUs are available if you have an ITX case. SFX power supplies are slimmer in comparison, and perfect for small form factor builds.
In May 2020, Intel created its ATX12VO guide for Desktop Power Supplies, which outlines a new design for 12V rail only desktops. It’s worth checking out the revised standards for better understanding of what may be coming in the future, although you don't need to worry about it just yet.
Here are some things to pay attention to when choosing a new PSU.
Weight
Most good quality PSUs will not be light, so pay attention to the weight of it! Power supply units that are of higher quality will use bigger capacitors, larger heatsinks and better chokes, which will weigh a lot more than the small, lighter ones that may not have quality components. Further, the cabling will be much sturdier, and shielded to reduce any noise.
Connectors
Although the vast majority of workstations, personal and gaming PCs use the standard ATX power supplies, server and enterprise units might have a different connector. Although most likely you will just need a standard ATX PSU, you should still double check your component requirements against your chosen PSU unit. Modular PSUs allow you to use only the cables you need, with sockets on the back of the unit.
Efficiency
Efficiency is extremely important in your chosen power supply unit. PSUs that are efficient have much better components, generate less heat, waste less power and by extension produce less noise.
The efficiency will be given in in percentage so if your PSU is 80% efficient, in simple terms it means that 80% of the PSUs power is fed to your rig and 20% is wasted as heat. When searching for a power supply, you will come across the 80 PLUS certifications. These certifications are a guarantee by the manufacturer that their product meets the efficiency requirements, and for our EU 230V system, the following table shows the efficiency levels depending on the amount of load:
| 80 PLUS Type | 10% Load | 20% Load | 50% Load | 100% Load |
| 80 Plus | | 82% | 85% | 82% |
| 80 Plus Bronze | | 85% | 88% | 85% |
| 80 Plus Silver | | 87% | 90% | 87% |
| 80 Plus Gold | | 90% | 92% | 89% |
| 80 Plus Platinum | | 92% | 94% | 90% |
| 80 Plus Titanium | 90% | 94% | 96% | 94% |
Output wattage
When it comes to the power output specs, a "peak output" or "peak power" can be misleading. Power supply manufacturers will list the power output of their products at the highest possible limits, but this doesn’t mean that the PSU can provide such voltage consistently nor for an extended period of time. The voltage that indicates the consistent and sustained power is the more important one to pay attention to over the peak power. Peak power, as already discussed, generally cannot be maintained for extended periods of time.
Manufacturers
As we’ve already discussed, choosing a reputable PSU manufacturer is crucial in ensuring your power supply is of good quality, correct for your rig and isn’t running a risk of destroying your internal components.
There are a number of reputable manufacturers that make great quality PSUs. We’ve compiled a short list of manufacturers that make high quality durable PSUs.
The type of PSU that will be ideal for you will depend on your setup and components, though it is generally thought that 750W is a sweet spot for most gamers.
Do note, however, that if you have extremely powerful hardware or you’re thinking of overclocking your rig, a higher wattage PSU will likely be needed. Mid to high-end graphics would generally need anywhere between 650W and 850W, though again, depending on your hardware you might need it to be outside said parameters. With more demanding components, more reliability at higher wattage is required, which is why the ATX 3.0 standard was put in place in 2022. If you aim to use high power components, ATX 3.0 may be for you.
Overclocking and calculating the real power consumption
If you’re planning on overclocking your rig, you will ideally need a much better understanding of your specs in order to pick a PSU that provides adequate wattage and can support your system.
This Power Supply Calculator is an excellent tool in helping you figure out exactly how much wattage you will need for your system. The basic part of the tool allows you to input your motherboard, CPU and GPU for a more accurate calculation of exactly how much power your rig will need. The expert panel allows you to calculate the required power using every singe drive and component you have or consider having in the future. Even if most of this seems too technical, the basic tool is extremely useful for gauging an idea of the type and the output of power supply unit you may need.
Need help in choosing a PSU? Contact us! Our team can help you choose the best PSU for your rig.
