How to Buy a PC Power Supply

How to Buy a PC Power Supply

One of the most important components to consider when building your computer or simply repairing a pc, is your computers power supply. The PC power supply is the backbone to any computer system, providing the fuel to run each computer processor, video card, hard drive and additional accessories that any given pc may have.

There are probably more budget models of pc power supplies on the market than quality, premium models. Generally speaking, when shopping for a computer power supply you get what you pay for. Cheap $20-$30 power supply models are not recommended for any application, so please resist the temptation to do so.

Many of these budget power supplies will fall short from fueling the power hungry computer components common in today's market. Poor quality electronic components are frequent to the budget power supply models, which can result in power fluctuations that can cause your pc to be unstable and even damage sensitive computer components.

PSU Wattage
When choosing the wattage of the power supply needed, you will need to estimate the total wattage used by all of the PC components that comprise your computer system. Make a tally of your components and add up the total wattage used and multiply by 1 ½ times. Ideally running a power supply at 30-70 percent of load capacity for the best efficiency.

MB (w/o CPU/ RAM) 50w to 100w
PCI-E VGA Card 100W to 225W
Older AGP VGA Cards 50w
PCI Card 10w
DVD/CD Drive 30w
Hard Drive 15w to 30w
Cooling Fan 3w p/fan
RAM 15w per 1GB of memory
Intel PIII CPU 40w
Intel P4/ AMD Athlon 80w to125w