Easy
Its easy dude, just figure out the total max current draw of all the items in your computer and add 15-25%. Thats how many watts you will require to run your system.
For example, all the items you buy should say the voltage and amperage they draw. Simply calculate that in to watts using this formula: Watts = Volts x Amps, and shabang, add all the watts of all the items. (a typical mobo and cpu take 120-200)
Furthermore, I will give an example of a typical system:
Mobo/CPU/RAM - 180w
DVD-RAM - 5Vx1.5A=7.5W and 12Vx1.5A=18W = 25.5W
HDD -5Vx.35A=1.75W and 12Vx.50A=6W = 7.75W
VID Card -5Vx2A=10W and 12Vx2.5A = 30W
Extra Fans -12Vx1.25x2 = 30W
Other -12Vx1A = 12W
Total = 285.25W
+ 25% (71.31W) = 356.56W total required.
All this hype crap about NEEDing 500 billion watts is just a load of crap, in fact most typical systems will do just fine on a nice stable 350watt PSU. Personally it is wise to use a 400W or better for expandability, and intial current draw, but if u just want to keep it simple follow the above and u shallant go wrong.
-Peace
Its easy dude, just figure out the total max current draw of all the items in your computer and add 15-25%. Thats how many watts you will require to run your system.
For example, all the items you buy should say the voltage and amperage they draw. Simply calculate that in to watts using this formula: Watts = Volts x Amps, and shabang, add all the watts of all the items. (a typical mobo and cpu take 120-200)
Furthermore, I will give an example of a typical system:
Mobo/CPU/RAM - 180w
DVD-RAM - 5Vx1.5A=7.5W and 12Vx1.5A=18W = 25.5W
HDD -5Vx.35A=1.75W and 12Vx.50A=6W = 7.75W
VID Card -5Vx2A=10W and 12Vx2.5A = 30W
Extra Fans -12Vx1.25x2 = 30W
Other -12Vx1A = 12W
Total = 285.25W
+ 25% (71.31W) = 356.56W total required.
All this hype crap about NEEDing 500 billion watts is just a load of crap, in fact most typical systems will do just fine on a nice stable 350watt PSU. Personally it is wise to use a 400W or better for expandability, and intial current draw, but if u just want to keep it simple follow the above and u shallant go wrong.
-Peace