What power supply do I need: keys to choose well and recommendations

The power supply is one of the basic pillars of any PC. When it comes to mounting a simple computer for office automation, the most common is to choose basic models and it is perfectly understandable since this type of systems has a minimum energy consumption and can work without problems with low-cost power supplies.

However, if our intention is to mount a PC to play we must be very careful when choosing the power source, since we will use components that may have a high energy demand and require, in addition, a high amperage. The same applies when we talk about high-performance equipment, such as workstations, for example.

To be able to choose the power supply, we must take into account the components that we are going to use since these will determine the power and amperage that we will need. However, we must also take into account other important aspects:

  • The energy efficiency
  • The number of connectors that it integrates.
  • The design (can be modular, semi-modular or standard).
  • Its form factor, very important if we want to mount a compact PC, for example.

Power supply: how much power do I need?

It is an important question that we can answer in a very simple way. If we are going to mount a basic PC for office automation without a dedicated graphics card and with a classic configuration (processor, RAM and one or two storage units), a 300-watt model is enough.

For you to have a reference we leave you the average consumption of a PC composed of an Athlon 200GE APU, two modules of 4 GB of DDR4, an SSD SATA III, a SATA III HDD at 7,200 RPM, an additional 120 mm fan and a keyboard and standard mouse: 197 watts.

On the other hand, if we are going to assemble a computer for games we must always take as a basis the requirement that the graphics card requires at the power supply level, but also taking into account the number of necessary connectors and the amperage.

Again we illustrate it with a couple of examples, a PC that mounts a Core i9 9900K at 5 GHz, two 8 GB DDR4 modules, an RTX 2080 TI at stock frequencies, a SATA III SSD, a SATA III HDD at 7,200 RPM, four 120 mm fans, and a standard keyboard and mouse will have a consumption of 586 watts. The ideal, in this case, would be to opt for a 650-watt source.

If we change that configuration to a Ryzen 7 2700X at 4.25 GHz and accompany an RTX 2060 the consumption goes down to 507 watts, so we would need a 550-watt source.

We already have clear the scale that we must follow when choosing a power source based on the power that we are going to use, but we must not forget the amperage, a value that measures the intensity of the electric current. The higher power graphics cards require higher amperage, so make sure that the source complies with the recommended minimum since otherwise, we could end up having stability problems in the short and medium term.

The necessary amperage is measured as a value associated with the 12-volt lane when talking about graphics cards. In general, the graphics cards of low and medium-low range conform with 16-18 amps, the mid-range models are around 20-26 amps and the high-end ones almost always exceed 30 amps.

Other things to keep in mind

We have already discussed the issue of format and connectors, two issues that have no mystery. We must buy a source that meets our needs both at the level of wiring and connections and size (the standard is the ATX, and there are others such as the SFX, designed for small and compact boxes).

Personally, I recommend you always choose something that is a bit above your short-term needs, as well as you have more room for maneuver when it comes to expanding the PC.

The management of the wiring is also important. In the modular sources, we can delete all the cables that we will not use, which allows us to achieve simpler and cleaner assemblies. On the contrary, in semi-modular sources, we can only remove part of the wiring, and in “standard” type sources we do not have that possibility.

We now turn to talk about energy efficiency, an issue that generates some confusion and that we will clarify next. We can define this concept as the electrical energy consumed by the work of the power supply itself, or what is the same, the power that it loses as a natural consequence of its operation.

The more efficient a power source, the more real power it will offer, a value that we can currently differentiate thanks to the 80 PLUS certifications, divided into a total of 6 categories that we order from worst to best:

  • 80 PLUS: 80% efficiency.
  • 80 PLUS Bronze: 82% efficiency.
  • 80 PLUS Silver: 85% efficiency.
  • 80 PLUS Gold: 87% efficiency.
  • 80 PLUS Platinum : 89% efficiency.
  • 80 PLUS Titanium : 90% efficiency.

Last but not least, we have the quality of construction of the power supply. Here come into play the components used, the cooling system and the protection technologies that a source integrates.

In general, low-price models that offer very high power levels tend to have a rather weak build quality. This does not mean that they are not able to offer an acceptable experience, but their quality of construction is almost always lower than that of other models with less power that cost the same.

As you can imagine, this has a very simple explanation, and that is that manufacturers use watts as a “hook” to attract the consumer. A source with more watts does not have to be better than one with fewer watts, keep it always present.

What power supply do I need for each graphics card?

Now that we have clear the most important concepts when choosing a power supply we will review a complete list where you will find the levels that we must meet in order to move with all the guarantees the main graphics cards of NVIDIA and AMD.

Bear in mind that we are talking about recommended values ​​and that they are associated with the reference models, which means that the versions with extreme overclock of some assemblers may require a more powerful source and the same, but in reverse, will happen with the model’s low consumption.

AMD graphics cards

  • Radeon VII – 38A and 750 watts (2 x 8 pins).
  • Radeon RX Vega 64 (standard) – 38A and 750 watts (2 x 8 pins).
  • Radeon RX Vega 56 – 31A and 600 watts (2 x 8 pins).
  • Radeon R9 Fury X – 34A and 600 watts (2 x 8 pins).
  • Radeon R9 Fury – 33A and 600 watts (2 x 8 pins).
  • Radeon R9 Nano – 28A and 550 watts (1 x 8 pins).
  • Radeon R9 390X – 31A y 550 vatios (1 x 6 pines 1 x 8 pines).
  • Radeon R9 390 – 30A and 550 watts (1 x 6 pins 1 x 8 pins).
  • Radeon RX 590 – 28A and 500 watts (1 x 8 pins).
  • Radeon RX 580 – 27A and 500 watts (1 x 8 pins).
  • Radeon RX 570 – 25A and 450 watts (1 x 6 pins).
  • Radeon RX 480 – 30A and 500 watts (1 x 8 pins).
  • Radeon RX 470 – 28A and 450 watts (1 x 6 pins).
  • Radeon RX 560 – 18A and 350 watts (1 x 6 pins).
  • Radeon RX 550 – 16A and 300 watts.
  • Radeon RX 460 – 17A and 350 watts.
  • Radeon R9-380 – 28A and 500 watts (2 x 6 pins).
  • Radeon R9-370 – 17A and 450 watts (1 x 6 pins).
  • Radeon R9-285 – 25A and 500 watts (2 x 6 pins).
  • Radeon R9-280X – 30A and 550 watts (1 x 6 pins 1 x 8 pins).
  • Radeon R9-280 – 25A and 500 watts (1 x 6 pins 1 x 8 pins).
  • Radeon R9-270X – 24A and 500 watts (2 x 6 pins).
  • Radeon R7 260X – 19A and 450 watts (1 x 6 pins).
  • Radeon HD 7790 – 21A and 450 watts (1 x 6 pins).
  • Radeon HD 7770 – 19A and 450 watts (1 x 6 pins).
  • Radeon HD 7750 – 16A and 400 watts.

NVIDIA graphics cards

  • GeForce RTX 2080 TI – 36A ​​and 650 watts (2 x 8 pins).
  • GeForce GTX 1080 TI- 35A and 600 watts (1 x 8 pins and 1 x 6 pins).
  • GeForce RTX 2080 – 35A and 600 watts (1 x 8 pins and 1 x 6 pins).
  • GeForce RTX 2070 – 32A and 550 watts (1 x 8 pins).
  • GeForce GTX 1080 – 32A and 500 watts (1 x 8 pins).
  • GeForce RTX 2060 – 30A and 500 watts (1 x 8 pins).
  • GeForce GTX 1070 TI – 32A and 500 watts (1 x 8 pins).
  • GeForce GTX 1070 – 30A and 500 watts (1 x 8 pins).
  • GeForce GTX TITAN X – 38A y 600 vatios (1 x 6 pines 1 x 8 pines).
  • GeForce GTX 980 TI – 38A and 600 watts (1 x 6 pins 1 x 8 pins).
  • GeForce GTX 1660 TI – 26A and 450 watts (1 x 8 pins).
  • GeForce GTX 1660 – 24A and 450 watts (1 x 8 pins).
  • GeForce GTX 980 – 30A and 500 watts (2 x 6 pins).
  • GeForce GTX 1060 – 20A and 400 watts (1 x 6 pins).
  • GeForce GTX 970 – 28A and 500 watts (2 x 6 pins).
  • GeForce GTX GTX 1650 – 16A and 300 watts.
  • GeForce GTX 1050 TI – 16A and 350 watts (1 x 6 pins).
  • GeForce GTX 1050 – 16A and 300 watts.
  • GeForce GTX 960 – 20A and 400 watts (1 x 6 pins).
  • GeForce GTX 950 – 19A and 350 watts (1 x 6 pins).
  • GeForce GTX 750ti – 18A and 350 watts.
  • GeForce GTX 750 – 16A and 300 watts.
  • GeForce GTX 740 – 16A and 300 watts (1 x 6 pin version with GDDR5).

Problems associated with an inadequate power supply

What happens if I use a power supply that is wrong? There are two great possibilities, that you have bought a source with greater power than you need or that you have done the opposite. In the first case, you will have nothing to fear, and in the second case, your entire team may be at risk.

Using a power supply with power or amperage lower than that required by manufacturers can have very different consequences that depend, in summary, on the quality of the source and how marked the difference between these values ​​and official requirements.

For example, a source that is only slightly below the consumption values ​​recorded by our team can offer an optimal experience and endure without problems, but when that difference is more marked we can experience serious problems. These are some of the most common ordered from lowest to highest severity:

Inconsistent performance.

  • High noise levels and elevated temperatures in the power supply.
  • Locks, restarts and sudden shutdowns of the system.
  • If we are in level three we must change the source as soon as possible, since the next step will be, almost with total security, the death of some component, including the source itself, which could also take the whole PC with it.

What power source should I choose? recommendations

  • We finish our guide of power supplies with a selection of several sources distributed in different ranges so that, regardless of your budget, you will find an option adapted to your needs and your pocket.
  • As always we have chosen to take into account especially the price-quality value of each power supply. It is not an exhaustive list since there are a lot of options and it is impossible to cover them all, but it is quite accurate and can also be used as a reference.
  • If you have any questions you can leave it in the comments and we will help you solve it.

– Gama basic:

  • Corsair VS450 450W 80 Plus White: it is an excellent option if we are looking for an economical but reliable power source with a good power level. Its power is 450 watts, reaches 36A in the 12V rail and comes with two 6 + 2 pin connectors. Its price is 39.99 euros.
  • NOX HUMMER X500W 80+ Semi-modular bronze: a good alternative to the previous one if you are looking for a semi-modular design. It has a power of 500 watts, 41A in the 12V rail and comes with two 6 + 2 pin connectors. Price: 49.99 euros.

– Mid-range:

  • NOX HUMMER X 650W Modular Gold: an excellent source that has 80+ Gold certification, has a modular design, offers 650 watts of power, 54A in the 12V rail and has two 6 + 2 pin connectors. Price: 84.99 euros.
  • Seasonic Focus + 750W 80 Plus Gold modular: this source is designed for high-end gaming equipment. Its maximum power is 750 watts, it offers 62A in the 12V rail and has two 6 + 2 pin connectors. Its price is 120 euros.

– High range:

  • Silverstone ST1000-PT 1000W 80 Plus Platinum: an ideal choice for equipment with multi-GPU SLI or CrossFire configurations. It has a modular design, offers 1,000 watts of power, reaches 83A in the 12V rail and has six 6 + 2 pin connectors. Price: 169.90 euros.
  • Corsair AX1000 1000W 80 Plus Modular Titanium: it is one of the best high-end power supplies that exist today, and as you can remember we analyzed in this article. It offers 1,000 watts of power and almost perfect efficiency. In the 12V line, it reaches 93A and has eight PCI-E 6 + 2 pin connectors. Its price is 249.99 euros.