Saturday, April 4, 2009

Choosing a Computer Power Supply Most Important Factors

When choosing a power supply there are few factors you should consider to getting the most suitable one for the power supply
  • Maximum power output, in Watts
  • Maximum current output in Amps (A)
  • Power efficiency
  • Brand name/Series
  • Number of connections and types
  • Price

Maximum power output, in Watts:

First you have to decide which amount of output power required for your computer. Other than manually calculations there are two easy systems which provides more accurate answer for this egg power calculator

NewEgg Power Supply Calculator

extreme power calculator
eXtreme Power Supply Calculator

From above I love extreme power calculator as it provides more options and therefore will be more accurate result. Let’s say the power calculator suggests you 400W then you should buy a 450W or 500W power supply other than your power supply will not be enough in some cases like hardware upgrades in future.

Note: overclocked systems need more power than its normal stage.

My recommendation is calculate using at least two calculators and get the average a of both result.

Maximum current output:

This is a fact which you need to consider if you’re using several dedicated video cards and etc which uses more current. If you have any doubt you have to ask from the vendor about the current requirement which most suits to your pc.

Power efficiency and usage:

Wasted power convert in to the heat of the computer. If there is lower efficiency that will heat your computer more and more. This will cause to dissipate your system fans as they required running faster in more heated environment. So you need to consider about Power efficiency otherwise your computer will boiled.

Electricity bill can be raise up for the non used wasted power.
Hence you have to be bothered about 80% or more power efficiency when buying a power supply.

Number of connections and types:

The most common type of connections are listed below.

20+4 pin Main Connector
4 pin 12V Plugged into the motherboard (May be 8 pin in some cases)
6 pin PCI-Express (for video cards, tv cards and etc)
6+2 pin(or 8 pin) PCI Express: (This can deliver even more power to the video card)
SATA power connector
Molex or Peripheral: (for older hard drives, optical drives, case fans, etc)
Brand/Series and etc..


Cheaper brand power supplies don’t offer any extra protection and other facilities which offer by the other branding products. There is more chance to drown your power supply after less amount life time period. Also which will cause to unstable some parts or the whole computer?

Cheaper models/brands will not offer any type of protection or only minimum that would be leaving your PC unprotected. Power protection will be important as the current supply of the area and etc.

Power does not fluctuate is called as clean power. Fluctuate current would be cause to unstable some parts of a computer. What I’m notice is some cheaper modules not bothered about this fluctuation of current. So it is best to choose one of the good branded product as they supplies more facilities and protection than cheaper brands.


Price is oscillating for brand names, types and etc. Whatever the brand name our aim is buying a most suited power supply for our computer environment. So it’s best to lookout a power supply unit which has best ratio between performance and price.


Anonymous said...

eXtreme Power Supply Calculator is more advanced and trusted one.

Post a Comment