Most (if not all) of the sold computer power supplies are assembled in China. Of course, no one has canceled the statement that “China to China is discord”, but the quality of the bulk of these devices, to put it mildly, is at a low level. This fact is not hidden by anyone, so the question often arises of how to choose a power supply. Moreover, even eminent manufacturers often indicate overstated percentages by 20 values of rated currents. In principle, they can be understood, because in conditions of fierce market competition for survival, all means are good, but the user ... he needs to carefully study the passport data of the equipment and understand well how to choose a power supply for the computer. That's what we’ll talk about today.
The power supply unit is located in the computer case and supplies electricity to all components. In general, the task entrusted to him is quite simple and has long been successfully solved in electrical engineering: standard 220 V AC is supplied to the input, and a whole bunch of constant voltages - 3, 5, 12 V, with both polarities, appears at the output. If you ask a consultant in a computer store a question “How to choose a power supply?”, He, of course, will advise on the optimal solution, but add that it is recommended to change the blocks every 1-2 years. This is an important addition that rarely anyone follows, but in vain. The internal elements of the switching power supply over time cease to correspond to the declared characteristics (for example, capacitors dry), so it needs to be changed.
So how to choose a power supply? The first indirect sign of a good block is its weight. It sounds funny, but it really is. Switching power supply - a rather complex product that requires careful adherence to the circuit during assembly. If you open a cheap Chinese unit, then the printed circuit board will surprise you with its emptiness: jumpers are soldered in place of the indicated elements, and the radiator can not be called massive. Therefore, when choosing, we are not ashamed to estimate the weight of the block by hand.
The second recommendation is known to everyone who has read a little how to choose a power supply. Still, we repeat: if possible, it makes sense to collect a little "extra" money and purchase a product from well-known companies - GlacialPower, Zalman, FSP, etc. Such a unit will ensure reliable operation of the computer, since its parameters more or less correspond to the necessary ones. Here is a life example: there are two power supplies - GlacialPower with a power of 450 watts and Codegen with 250 watts. Compare passport data and ... we understand that everyone has their own math. The total declared Codegen power on the plus lines of 3 and 5 V is equal to the same parameter for GlacialPower! The conclusion is obvious - you can buy cheap Chinese blocks, but with a twofold reserve in power, and use them no more than a year. In addition, branded products support various "goodies", for example, intelligent fan control, which means such valuable silence during operation.
In modern systems, the main load falls on the +5 and +3.3 V lines, so the unit must be selected according to the maximum current of these lines (the more the better). On the sticker with the passport data, these values are always given. If the power of these lines is less than that of the processor, then we are looking for a more efficient model.
Before going to the store, it is recommended to calculate the power of the power supply. There are special programs or sites for this. It is necessary to indicate the type of processor, video card, memory, etc. At the same time, remember that the obtained value will be indicative, and the model should be selected as “calculated value + 20%”.
Summarize:
- calculate the required power;
- choose a heavy branded power supply;
- make sure that the power of +3.3 and +5 V is enough.
In addition, you can pay attention to the number of power connectors: sometimes the connectors for SATA hard drives are not enough and you have to use adapters with Molex, which is not very convenient.