PSU wattage Calculator

I found this calculator on the internet,
http://www.jscustompcs.com/power_supply/
I was just wondering how accurate teh approximation is, my friend needs to get a replacement for his system and i was using this to get an estimate. I'd appreciate any information on it.
Thanks,
xb-70

As discussed in another thread, the power estimates are acceptable with two exceptions.

1. The calculator uses a per stick wattage rather than a watts per xxx MB formula which is more generally accepted.

2. The motherboard figure is accurate for simple OEM boxes like Hewlett Compaqard, Dell, eMachines... Not the sorts of motherboards people reading these forums are likely to use. Add 20 to 25 watts to the figure they use.

Also, you must notice that the caluculator includes a 30% factor of safety. When you select 100W of components, the total goes up by 130W. This is a good thing to do in sizing a power supply, but the site does not mention this feature. If you buy a power supply with the rating suggested it will be sufficiently OVERSIZED to allow for major upgrades in the future.

No

that aint a bad calculator actually as long as you dont quote exact numbers off it, its really good as a rough guide as to what you use. thoughtfull as well how the guy added a safety margin. isnt as in depth as id like it to be but i can account for that easily.

I ran an Athlon XP1800+ with an ECS K7S5A Pro, 256MB PC2100, and ancient Diamond Stealth 2000 PCI video card, and during test #4 of MemTest86 the mobo drew about 44W (7.3A @ +5V, 2.3A @ +3.3V). When I ran this with an ECS P4S5A2, 1.7 GHz Celeron (.18u), 256MB PC2100, and Intel i740 AGP card, the draw was from 58-76W (8.5-12A @ +5V, 4.7A @ +3.3V).

Its a pretty good tester... and proves the fact that Sirtech (highpro) makes some pretty damn stable mATX PSU's, as my XP2100 / Ti based system uses much more power than it supplies.

Cheers, Flix