Given that I am building a home computer from scratch and I have several components (MB, CPU, HDD, Video, Sound, etc) which have specific power requirements, is there a formula for me to calculate the size/capacity of the Power Supply I will need? I want to be able to expand the setup later on also…
Solution:
Add up the wattage on all the labels and round up.According to PC Power & Cooling:
- AGP Video Card 30W – 50W
- PCI Express Video 100W – 250W
- Average PCI Card 5W – 10W
- DVD/CD 20W – 30W
- Hard Drive 15W – 30W
- Case/CPU Fans 3W (ea.)
- Motherboard (w/o CPU or RAM) 50W – 150W
- RAM 15W per 1GB
- Processor 80W – 140W
They also state:
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.)