what PSU would I need for these specs?

Hi.

Hope somebody can help me out.

I was looking into a 550w powercooler (two 18A 12v rails) or antec PSU (three 18A 12v rails) for my new rig. Some say it's enough and others that it is not.

Here are the specs:

1 intel e8500 oc'ed to 3.8 (hopefully)
1 asus p5q-e
1 sata 750gb seagate
1 nvidia geforce 9800GT
2 x 2gb = 4gb of OCZ 1066
1 DVDRW
1 ARctic freezer 7 with 92m cooler

and the usual stuff... couple of USB devices plugged in here and there...


I used an online calculator and got 387w.


what do you guys think?

btw: is one 12v rail with 60 amps better than 3 o 4 with the amps divided amongst them?

thanks.