Choosing a PC Power Supply by Power Comparison

Corsair HX Professional

Power supply is probably the most computer components are often overlooked by PCs buyers. However, this component is very important : such as when the power is insufficient or if the voltage is too unstable, the power supply can cause crashes or reboots the machine. Even worse, if power is working too hard and / or in poor quality, maybe just by turning on the computer may cause damage to most of the components: motherboard, CPU, hard drive and a DVD player!  Note that branded manufacturers are also found in the market often overlook the power supply in order to reduce the selling price of the computer. Most buyers assume the power supply is not important, some unscrupulous manufacturers introduce large-sized power and poor quality for their machines.


1. Buying guide ho to choose your best power supply: what power? What brand?

In this guide it is given some general tips to determine the power required from the power supply and provide interesting references to be matched with your PC. This recommendation is based on tests of power that is found in the computer press and on the Internet (there are more). Indeed, the technical characteristics are not sufficient to describe the power: the real test is sometimes very different … The quality of power supply found in the market varies according to brand, price is often associated with quality but you can find quality power supply at affordable prices (and expensive power supply with low-quality …). Noise from the power supply also an important parameter to consider, especially if other components (cooling the CPU, graphics card …) chosen silence, of course.

2. What power and what features should be chosen?

Power problem is difficult to determine because it is not easy to calculate the consumption of computers, especially in practice there is no PC components work together and in maximum condition. In general, the power used should not exceed 70-80% of the total available power, more power can be very noisy when approaching the maximum (fan noise is very unpleasant). Components that require the majority of energy is the processor and (or) card (s) graphic (s).

It is also sometimes necessary to take more powerful power supply than required for backup in case of upgrading the processor or graphics card changes. This is especially true when you want to switch to a configuration of two GPU (by adding a second graphics card) uses the ability of ATI CrossFire chipset and NVIDIA SLI. High-end graphics cards consume a lot of electricity and requires a lot of power to the power supply but not as much as some manufacturers would have us believe (by offering the power of 1000 or 1500 watt totally useless …).

You should also know that the 700w power supply does not consume more electricity than a 300W power supply (with the same configuration at the rear). As the performance of power it is very important that you can save energy and environmentally friendly.

The quality of power supply also plays a role in the stability of your computer for your own safety. Indeed, some power supplies on the market (some brands do not mention) are dangerous and no meet the standard: no PFC, filters EMI (electromagnetic interference), labeled with 400 watts of fact only 200 watts. This risk destroying your entire PC, more seriously, a fire in your house are really exists.

To give you an idea, a typical office config using a modern processor (AMD Phenom, Intel Core 2 Duo) coupled to an inefficient video card (or integrated) may work fine with a power of 300 or 350 watts. A mid-range config equivalent but with a more powerful graphics card like the Radeon HD 5830 or GeForce GTX 460 requires a power of 450 watts to be “comfortable”. Config for a gamer using a very powerful graphics card as a high-end Radeon HD 5870 or GeForce GTX 480, it is necessary to have a power of 600 watts if the machine is loaded and combined with a large processor (Core i7, Phenom X4 …). For a “war machine” two large powerfull GPU, NVIDIA recommends at least 750 watts for power supply! (the figure is a bit overrated to reflect the low quality of some power supplies).

Be careful to ensure that the power supply has all the connectors needed for your configuration, for example for high-end graphics card, psu should have a PCI-Express 8-pin (two for dual GPU).

3. Buying Guide, Our choice of best power supply model:

All power supplies are offered here is quite quiet, high efficiency (which is environmentally friendly and save energy) and with high quality.

Best 350W-450W ATX Power Supply :

Best 450W-550W ATX Power supply :

Best ATX Power Supply over 550W :