Hardware Resources

Power Supplies

How Much Power Do You Need?

Component Requirement
Motherboard 50W - 150W
Processor 80W - 140W
RAM 15W per 1GB
Hard Drive 15W - 30W
DVD/CD 20W - 30W
AGP Video Card 30W - 50W
PCI Express Video 100W - 250W
Average PCI Card 5W - 10W
Case/CPU Fans 3W (ea.)

For overall power supply wattage, add the requirement for each device in your system, then multiply by 1.5.
(The multiplier takes into account that today's systems draw disproportionally on the +12V output. Furthermore, power supplies are more efficient and reliable when loaded to 30% - 70% of maximum capacity.)

by Lazar Rozenblat

Your guide to computer (PC) power supply: types and connector pinouts. Find ATX schematic diagrams, theory of operation, wiring, repair guides and other online info and resources for DIY projects.

Additional Power Supply Information
by PlayTool

eXtreme Power Supply Calculator

The eXtreme Power Supply Calculator contains 1300+ CPUs including latest processors from Intel and AMD, latest graphics cards from NVIDIA, AMD and more!

Journey Systems Power Supply Calculator