I add 100 Watts to whatever it comes up with....
The following two articles detail why!
The first link shows how to calculate the size. The next link is why I add 100 to that total.
http://www6.tomshardware.com/howto/20040122/
http://www.tomshardware.com/howto/20021021/
Bob
PS. Not to mention that power supplies age so you need more Watts that you calculated to get a machine that will run well for more than a year.
What wattage of power supply would you reccomend for the following system?
((I'm homebuilding this, it'll be my second homebuilt system, used mainly for gaming and media stuff so SPEED is the number one need))
Case: RaidMAX Virgo 811 (comes with 420W PS)
MB: MSI 67023-020
Processor: Athlon 64 3500+ Socket 939
Processor Cooling Unit: Zalman CNPS 7000A
RAM: 2x Kingston 1GB DDR400 kits (4x512MB)
HDD: 2x WD Raptor 36 GB HDD (Raid 0)
Video: ATI All-in Wonder 9600XT
DVD/CD R/W: Toshiba 8x4x12x DVD+-RW/32x CD-RW
Add on the built in 120mm and 80mm fans on this case (I'll prob add another 120mm). Do you think the 420 W PS provided with the case will have ample power to take care of all this shtuff?
(BTW, this will all cost me less than $1500 to build and it'll smoke any pre-built system from Dell or the like, I think. Your feedback would be appreciated)

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