Build-Your-Own Computer Part 2: Power Supply

Buying a new computer can be an expensive ordeal. When you go to a big box retailer or manufacturer, you often pay for components you don’t need or get overcharged for the ones you do. The best solution is to build your own computer. What most people don’t realize is it’s actually surprisingly easy to do. To help you design your next computer, or just to become familiar with what to look for, WorldStart is doing a 10-part series on the components you’ll need to build your own computer.

In each part, I’ll offer recommendations on the components discussed. I’ll recommend parts to accommodate those both looking for value and those looking for high performance. Since manufacturers are always updating styles and features, your final decision should be based on your own judgment, aided by the knowledge you gain from these articles. You know what you want from your PC, I’m here to help you design it.

Part Two: Power Supply

The power supply converts your home’s electrical power into the DC power your computer requires to. The power supply is the number one thing to go wrong with a computer, so choosing a correct one can be the difference between years of service or hours of frustration. These five simple- to-understand specifications for a power supply, will allow you to choose the best one for your needs.

Wattage: This is the simplest of the specifications to understand and correctly account for. The wattage is a measurement of the peak energy the power supply can offer to your system. The best way to determine the size you need is to add up the wattage listing on all of your components and then multiple by 1.25. Buying a power supply with a very high wattage listing won’t damage your computer or raise your electric bill, since only the needed energy will be drawn.  A power supply with too few watts will prevent the components from functioning correctly.

Connections: The types of connectors a power supply has vary based on the model of power supply. All will contain the standard connectors needed to power your mother board, processor and hard drives/optical drives. Some power supplies will include one or more dedicated PCI-E power plugs. It’s a good idea to make a list of any special power plug requirements your components need and make sure your power supply has those plugs. A power supply with more connectors than you need won’t hurt you, but the absence of a needed connector will.

Modular:  If the power supply is designed to have plugs which can be removed or added as needed to the power supply, it is referred to as modular. A modular power supply will cost more, but make the power supply area neater by allowing you to only connect the cables you need.

Cooling: Power supplies generally have active cooling, meaning they have a fan which cools the internal components. A larger fan is better, as it will have lower noise than a smaller fan and produce lower power supply temperatures. Passive-cooled power supplies should be avoided, as they do not include any fan.

Efficiency:  Efficiency refers to how much wasted energy there is when the power supply converts the AC wall power to DC current.  Efficiency is rated from lowest to highest as bronze, silver, gold or platinum While a higher efficiency power supply is ideal, the cost increase is often not worth it over the life of your computer.

My Recommendations:

Budget Power Supply – Antec EarthWatts EA-650 GREEN 650W – $69.99

Antec, an seasoned producer of high-quality power supplies, has a really attractive offering with 650 watts of power, a large 120 mm fan, wrapped cables and PCI-E power connectors.  The EarthWatts series does not ship with a power cord, so you’ll need to reuse an old one or buy a new one. It offers a high-quality, dependable power supply for the masses. 

Premium Power Supply – PC Power & Cooling Silencer Mk III Series 850W – $159.99


PC Power And Cooling’s 850 watt power supply offers all the standard power supply features along with modular cables, 6 PCI-E connectors for full SLI/crossfire gaming and 80 Plus Gold efficiency certification. This is a fantastic power supply for someone looking for a high-quality, high-power unit that can upgrade with them for years to come. 


P.S. Normally I wouldn’t say what to avoid, but DO NOT cheap out on a power supply. This is the device which is going to provide the power to all of your devices. A defective one can not only burn out but damage other devices. The budget recommendation is as low as I would go in price.tTe cheaper $40 and under power supplies are made with lower-quality capacitors and have fewer electrical protection systems. 

Click here for more articles in this series

3 thoughts on “Build-Your-Own Computer Part 2: Power Supply

  1. Lonnie check out the news letter from 2013-08-19 for the first part. It was dealing with cabinets or cases for the componets…I’ll forward my copy to you, I think I still have it.

  2. Hello! thank you very much for this interesting and useful tips! I have made pc be myself too and your post have helped me to choose power supply. I am totally satisfied with my new pc!

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