Computer power consumption questions

[MonkeyFaces]

Here's all the hardware in my system: E6300@ 2.1ghz, 2x 7900gt, 72gb raptor, 250gb 7200.1 sata, 2x disk drives, about 5 usb devices, x-fi, antec 550 neo HE, 2x 1024mb ddr2 533 ram

My questions are: 1. What would my idle and full load power consumption ratings likely be coming from the wall socket (how much the psu draws, not the components drawing power from the PSU)? 2. If my system were rated to consume 200watts, is this value per hour? 3. Am i wasting loads of money if I leave my SLI system on for 24 hours consistently for the purpose of downloading?

 

[Seekermeister]

This will help to calculate the maximum:

http://extreme.outervision.com/psucalculator.jsp

But the average would either have to be determined with a tester, or with something like APC's PowerChute.

 

[John]

You could be pulling 200w under load, and your electric co. should charge you per kWhr.

200 (watts) / 1000 (kW) * .13 (about what I pay per kWhr in TX so ymmv) * 24 (hours) = $.62 per day * 30 (days) = $18.72 per month

 

[MonkeyFaces]

Would it be smart to assemble a computer for the purposes of downloading? How much power should a geforce 4 mx, p4 3ghz, and a standard HD, and a cheap 75% efficient psu pull? Will I be able to share files between the 2 computers using windows home edition, or would I need to upgrade to professional? If so, can anyone recommend a method of transferring large files between 2 computers efficiently besides networking?