Source: wikipedia

From next generation CPUs, to the fastest RAM, to the beefiest graphics cards—if you’re building a gaming PC, chances are you’ve already got your heart set on the latest and greatest PC components.

But there’s one more component that often gets overlooked: the power supply. It won’t improve your framerate and it isn’t the most aesthetically appealing part of a build, but without a power supply, your gaming rig is literally dead weight.

Beginners often make the mistake of settling for a cheap off-brand unit that boasts a large power supply rating. Others might overspend on a larger power supply rating to ensure they’ll have enough juice for their high-end components. 

But if you’re looking to build a gaming PC that will last, a good power supply is a must. Here’s what you need to know about picking a power supply for a gaming PC.

How much wattage do you need?

It’s no secret that high-speed circuits such as GPUs and CPUs are energy hogs. Add fans, lighting, and liquid cooling to the mix, and you begin to understand how much energy you’ll need to power your rig.

You can find power consumption requirements for different components online from manufacturers or on sites such as Tom’s Hardware. Or you could just use a handy power supply calculator like this one from OuterVision. It lets you build a hypothetical rig by selecting parts from drop-down menus and calculate the recommended wattage for your system.

Here are some typical benchmarks for power draw requirements for high performance PC components:

• CPU: Intel Core i7-9700K CPU, 95W

• Video Card: Nvidia GTX 1080 Ti, 250W

• RAM: DDR4 2133 8GB, 3W

• SSD: Samsung SSD 850 EVO 500GB, 4W

You’ll notice that the video card takes up a lot of power. Maybe you don’t really need the latest flagship Nvidia GTX Titan series card, and can settle for last year’s model. The Nvidia GTX 1070 Ti only draws 180W. It won’t only save you on the cost of the card, but also the cost of your energy bill and the power supply unit for your rig.

It’s not all about size: 80 plus rating system

Besides the raw power rating listed on a power supply, energy efficiency is another important metric that you’ll want to understand.

Your GPU, CPU, and other computer components all run off of DC (direct current) power. Your wall outlet only supplies AC (alternating current) power. When your power supply converts AC power from the wall into the DC power used by the rest of the components in your gaming rig, at least some of that energy is lost as heat.

That means you’re never getting 100% of the power drawn from your wall. So how do you compare two power supplies that have close to or the same wattage rating?

Enter the 80 PLUS rating system. It was created to encourage manufacturers to create more energy efficient power supplies. The 80 PLUS rating system certifies power supplies are able to convert more than 80% of the AC power received from your wall into the DC power needed by your components. There are six levels for non-redundant (power) power supplies:

• 80 PLUS: 80%

• 80 PLUS Bronze: 82%

• 80 PLUS Silver: 85%

• 80 PLUS Gold: 87%

• 80 PLUS Platinum: 89%

• 80 PLUS Titanium: 90%

All efficiencies were based on 100% of rated load. Efficiencies can be higher at lower loads, as with 80 PLUS Titanium hitting 94% efficiency at 50%.

Budget for a quality power supply in your wattage range

While it can be tempting to snag deals on power supplies with high wattage ratings, it’s important to do your due diligence and check user reviews, manufacturer reputations, power draw requirements, and energy efficiency ratings. Often times if a deal sounds too good to be true, it probably is.

The right way to save money on power supplies is to pick a quality unit from a reputable manufacturer that’s within your required wattage range. Be sure to add enough margin to account for any upgrades you plan to make in the future. Choose the best power supply for your needs.