12v amps needed for xfire 4890's?

[hsu_alum]

So I'm plotting to build a midrange system with the following:

i5 750 (want enough power to get a good o/c out of it)
decent overclocking p55 mobo
4gb ram
2 ati 4890's in xfire
1-2 7200rpm sata drives
~4 120mm fans

I'm under the impression that besides a good manufacturer, lots of amperage on the 12v rail(s) is what I should look for. If I'm on the right track, how many amps do I need?

I was looking at getting one of those fugly xfx 750w psu's for ~$100. Good choice? Should I be looking for more amps or a better deal?

 

[theAnimal]

That would be a fine choice.

You could also go with XFX 650, Corsair HX650, Antec TruePower New 650/750.

 

[HOOfan 1]

If you don't mind the look of the XFX $100 is a great deal

 

[hsu_alum]

The xfx 650w can be had for about $60 after rebates, would the 650 (which has 52amps, 750 has 62amps) have enough to o/c my proposed system? I'd rather save the $40 if i don't need the extra amps. Afaik each 4890 draws 20-22 peak amps off the 12v. How much do I need left for o/c'ing an i5 750?

 

[theAnimal]

Afaik each 4890 draws 20-22 peak amps off the 12v.

That would be more like the combined power draw. You'd be fine with the 650W.