At the time of buying a computer, part by part, one of the components that least receives attention is the power supply. This component is key for the correct functioning of the computer. We will explain why is not enough to say “I’ll just use the same 600W power supply”. When choosing a power supply, we have to check many factors, which can be summarized in quality of the components, stability, security, efficiency, power and quality.
The higher the quality of the components, the longer will be the useful life of the power supply. In addition, higher quality power supplies usually have a longer warranty, from 5 up to 10 years. A poor quality power supply could have a shorter useful life and damage other components if it fails.
Stability and security
Better components imply higher stability in power input. Furthermore, when buying a power supply, you have to look at the maximum time it can stay on without electricity. This is good to know in case there is a voltage drop. The minimum acceptable is around 17 milliseconds.
Another detail to have in mind, is that the power supply must include, preferably, an internal switch. We will know if it has it or not if when the computer is turn off a faint clicking sound can be heard. This switch will protect our components in case of a short circuit. If there is a short circuit, the power supply will detect it before it gets to the rest of the components
Efficiency and power
This is maybe the most important detail when buying a computer. Power supplies divide in different categories, under the 80 PLUS certification. This certification classifies power supplies according to its level of efficiency:
The higher the efficiency of a power supply, the higher will be the power it can intake. A 700W power supply with a standard certification can really give 500W. 700W is the amount of energy it can intake to provide the computer with 500W. A 700W titanium power supply can provide 680W, or even go over that, depending on the situation. This factor is very important in long term, for we can save in a couple of years the money expended in an expensive but more efficient power supply.
In addition we have that the efficiency of a power supply will vary according to its charge. A computer with an i7-6700K processor and a NVIDIA GTX 1070 graphic card will consume at its highest 450W. However, we shouldn’t buy a 450W power supply or even a 500W power supply. It’s good to leave certain margin, especially if we don’t want to exhaust the power supply, and also because the highest efficiency is achieve when the power supply is half charged. For this reason, we must think what our PC’s average and maximum charge will be, and choose the power supply in that respect. For the previously mention computer, a gold certificated 600W power supply would be the best option in a quality-price-efficiency relationship. For a computer with a 1070 SLI, an 800W power supply would be advisable.
Standard of quality
The quality of power supplies is given by different factors as is efficiency and materials quality. The quality of these is usually measured in terms of the capacitors used by the brand.
The Japanese ones are the best for any user.
- · Level 1. (The Best) this groups the highest quality power supplies, which are the titanium and platinum ones. They are the most recommended. They use industrial quality components and can work at temperatures up to 50°C. Some models of this quality are the Corsair HXi, AX/AXi and RMi, Seasonic M12 and EVO series, EVGA Supernova G2 or Seasonic Platinum, Snow Silent and X Series. They are also the most expensive, and the ones that offer more power. For a PC gamer it may be a little too much. Most of them are Titanium or Platinum.
- Level 2. (Excellent/Good) This groups power supplies of excellent quality, and is the best option for the average user that can afford good quality components for its computer that assures a longer useful life. They use capacitors 100% made in Japan. Power supplies of this level are some such as the Cooler Master VS Series, the Corsair GS, RM, and TX, Seasonic S12 and G Series. From this range, most of them are Platinum or Gold.
- Level 3. (Decent) these are of acceptable quality and may include Taiwanese or Japanese capacitors. They are still stable, but have lower quality components. They are not advisable for constant high charges, but are more than enough for a gaming omputer. Some models are the Corsair CS, EVGA 430W/500W, Most of the ones found in this category are Gold or Silver.
- Level 4. (Bad) These use Taiwanese or, even, Chinese capacitors. They are not advisable for gaming computers. It’s convenient to avoid them. Some of these are the Aerocool GT Series, Strike-X or Corsair CV and VS. Most of these are found on the Bronze category.
- Level 5. (The worst) Must avoid at all cost. They probably don’t even have an 80 PLUS certification. If they don’t, more reason to avoid them. They are not safe, use Chinese capacitors and usually offer high power, that barely achieve (700W ones that actually provide 450W) this power supplies could damage your computer if they were to fail, which is likely due to the poor quality of its components. These don’t usually belong to a well-known brand and have high risk of failing.
Levels 1 and 2 and most of level 3, are power supplies that include compatibility with Haswell’s low power modes and Intel processors, allowing a low consumption in sleep mode. Also, most of this models work in sleep mode, without having to use the fan.
Lastly, we remember an important difference. There are three types of power supplies: modular, partially modular and non-modular power supplies. The modular power supplies allow to choose any cable we need to plug in. Partially modular generally have cables such as the mother board power cables, and non-modular power supplies don’t allow us to choose any wire and we will have loose cables inside the case.
We will leave you some links that have the full list of quality levels. The first is a vertical list, and the second a horizontal one, with little variations in models, and the second list divides the second quality level in two parts.