What is a power supply and what is it for?
A power supply unit (PSU) is a device for converting mains voltage (220 volts) to specified values. To begin with, we will consider by what criteria you can choose a power supply for your computer, and then we will consider some points in more detail.
The main and main selection criterion (PS) is the maximum power required by computer devices, which is measured in units of power called Watt (W, W).
About 10-15 years ago, for normal operation of an average computer, no more than 200 watts were required, but in our time this value has increased, due to the appearance of new components that consume a large amount of energy.
For example, one SAPPHIRE HD 6990 graphics card can consume up to 450 watts! Those. To select a power supply, you need to decide on the components and find out what their power consumption is.
Let's look at an example of how to choose the right PSU (ATX):
- Processor - 130 W
- -40W motherboard
- Memory -10 W 2pcs
- HDD -40 W 2pcs
- Video card -300 W
- CD-ROM, CD-RW, DVD -2 0W
- Coolers - 2 W 5pcs
So, here is a list with components and the power consumed by them, to calculate the power of the PSU, you need to add the power of all components, and + 20% for the stock, i.e. 130 + 40 + (20) + (80) + 300 + 20 + (10) = 600. Thus, the total power of components is 600 watts + 20% (120 W) = 720 watts i.e. for this computer, a power supply of at least 720 W is recommended.
We figured out the power, now let's try to figure out the quality: it’s powerful, it doesn’t mean quality. Today on the market there are a large number of power supplies from cheap nameless to very well-known brands. A good power supply can also be found among the cheap ones: the fact is that not all companies make PSUs themselves, as is customary in China, it’s easier to take and make some eminent manufacturer according to the ready-made scheme, and some do it very well, so decent quality can be meet everywhere, but how to find out without opening the box is a difficult question.
Nevertheless, you can give advice on choosing an ATX power supply: a high-quality PSU cannot weigh less than 1 kg. Pay attention to the wire marking (as in the picture) if 18 awg is written there, then this is the norm if 16 awg, then this is very good, but if 20 awg, then these are already low-quality wires, you can even say marriage.
Of course, it is better not to tempt fate and choose the BP of a proven company, there is both a guarantee and a brand. Below is a list of recognized brands of power supplies:
- Delta power
There is another criterion - the size of the power supply, which depends on the form factor of the case where it will be installed, and the power of the PSU itself, basically all power supplies are ATX standard (shown in the figure below), but there are other PSUs that do not apply to certain standards.