How Much Power Do You Need?
||50W - 150W
||80W - 140W
||15W per 1GB
||15W - 30W
||20W - 30W
|AGP Video Card
||30W - 50W
|PCI Express Video
||100W - 250W
|Average PCI Card
||5W - 10W
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.)
GUIDE TO COMPUTER POWER SUPPLIES
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
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