Connector. Over the years, all motherboards use 20-pin power connector. Now, the new PCI-E requires 24-pin connector. Of course, there are adapters that allow you to connect 20-pin Power Supply to 24-pin connector, but adds an extra loads on the power supply.
Noise : PSU fan is probably the loudest component of your computer. Several power supply is available with quieter fans, or even without a fan, but this would mean working at higher temperatures. Blocks with the quiet fans are much more expensive than usual.
Power. It’s important to choose a power supply with a capacity that best meets your computer needs. Lack of power will lead to hardware failure, but if more than you need – it will be a useless waste of money and energy consumption. Then How to determine the power required?
Standard computer works fine with 400 W power supply Need a more powerful 450 and above.
Buy power supply unit, stay away from the power supply manufacturers offer low prices but the quality is questionable. Work, but interruptions and discontinuities rather constant supply of electrical energy that is damaged can reduce the lifespan of your computer. Now save twenty bucks, you could lose hundreds of years. It is highly recommended you seek a reference from the nearest computer shop or look for reviews on the internet.