Comparison Chieftec Force CPS-650S vs Chieftec Smart A8 GPS-700A8

The output power of the power supply, in other words, is the maximum power that it is capable of delivering to the system. For the computer to operate efficiently, the power supply must be greater than the total power consumption of the system at maximum load. The latter can be calculated by summing the power of individual components, however, in general, for office configurations , about 400 W — 450 W is considered sufficient, for medium gaming — about 600 W( 500 W, 550 W, 650 W, 700 W, 750 W), and for the top ones — power of 800 W and above ( 850 W, 1000 W and even more than 1 kW).

Efficiency, in this case — the ratio of the power of the power supply (see "Power") to its power consumption. The higher the efficiency, the more efficient the power supply, the less energy it consumes from the network at the same output power, and the cheaper it is to operate. Efficiency may differ depending on the load; the characteristics can indicate both the minimum efficiency and its value at an average load (50%).

It should be noted that compliance with one or another level of 80PLUS efficiency directly depends on this indicator (for more details, see "Certificate").

The bearing is the piece between the rotating axle of the fan and the fixed base that supports the axle and reduces friction. The following types of bearings are found in modern fans:

— Sliding. The action of these bearings is based on direct contact between two solid surfaces, carefully polished to reduce friction. Such devices are simple, reliable and durable, but their efficiency is quite low — rolling, and even more so the hydrodynamic and magnetic principle of operation, provide much less friction.

— Rolling. They are also called "ball bearings", since the "mediators" between the axis of rotation and the fixed base are balls (less often — cylindrical rollers) fixed in a special ring. When the axis rotates, such balls roll between it and the base, due to which the friction force is very low — noticeably lower than in plain bearings. On the other hand, the design turns out to be more expensive and complex, and in terms of reliability it is somewhat inferior to both the same plain bearings and more advanced hydrodynamic devices. Therefore, although rolling bearings are quite widespread nowadays, however, in general, they are much less common than the mentioned varieties.

— Hydrodynamic. Bearings of this type are filled with a special liquid; when rotated, it creates a layer on which the moving part of the bearing slides. In this way, direct contact between hard surfaces is avoided and friction is significantly reduced compared to previous...types. Also, these bearings are quiet and very reliable. Of their shortcomings, a relatively high cost can be noted, but in fact this moment often turns out to be invisible against the background of the price of the entire system. Therefore, this option is extremely popular nowadays, it can be found in cooling systems of all levels — from low-cost to advanced.

— Magnetic centering. Bearings based on the principle of magnetic levitation: the rotating axis is "suspended" in a magnetic field. Thus, it is possible (as in hydrodynamic ones) to avoid contact between solid surfaces and further reduce friction. Considered the most advanced type of bearings, they are reliable and quiet, but expensive.

The presence of at least one Floppy power connector in the PSU.

Initially, this connector was intended to power floppy disk drives, hence the name. It is also known under the designation "mini-Molex". Anyway, this standard is generally considered obsolete, but it is still used by some specific types of components, and therefore continues to be used in power supplies.

The maximum current that the PSU is capable of delivering to the first power line is + 12V.

For more information about power lines in general, see "+3.3V". Here it is worth mentioning that 12 V is the most popular voltage among computer power connectors. It is used in almost all such connectors (with a few exceptions), and some plugs (for example, additional PCI-E power for 6 or 8 connectors) use only 12-volt lines — and in the + 12V format. And the division of + 12V power into several separate lines is used for safety purposes — in order to reduce the current flowing through each individual wire, and thus prevent excessive load and overheating of the wiring. However, some manufacturers do not specify the maximum current for individual + 12V lines and give only a general value in the characteristics; in such cases, this number is indicated in this paragraph.

The maximum power that the PSU is capable of delivering to the + 12V power line.

See "Maximum current and power" for details on power lines in general. Here it is worth mentioning that 12 V is the most popular voltage among computer power connectors. It is used in almost all such connectors (with a few exceptions), and some plugs (for example, additional PCI-E power for 6 or 8 connectors) use only 12-volt lines — and in the + 12V format. So this indicator is one of the most important characteristics of any PSU.

Note that many power supplies have several separate + 12V power lines. In such cases, the total power is indicated here, which, usually, is divided equally between the lines.

The maximum power that the PSU is capable of delivering on the + 3.3V and + 5V power lines.

See "Maximum current and power" for details on power lines in general. Here we note that the power lines + 3.3V and + 5V are used both in the general connector for the motherboard (for 20 or 24 pins), and in specialized plugs — in particular, the SATA power connector (both) and Molex (only +5V, in addition to +12V). The power of these lines is a rather specific parameter, rarely required in fact; it is usually the same for both voltages, so it is indicated in the general clause.