I have seen systems at load taking 40-50 watts using core duos and according to x-bit labs a 7600gs only takes 28 watts max. Can someone confirm the wattage of a 7600gs?
In their testing they just took a 7600GT and underclocked it to the frequency of a 7600GS (because they have the same core). 28W was the result.
But the real 7600GS are undervolted, the core is at 1.1V contrary to 1.3V for the GT (that a fact for the passive 7600GS, I don't know if that's true for the fan-cooled 7600GS).
Memory is also less demanding bus-wide and frequency wise so a couple watts saved here too.
According to hkepc.com, the 7600GS is consuming 24W, I don't know if that's a real measurement or just straight from the manufacturer factsheet though.
Combining the theoritical, full-voltage 28W and the undervolting I would guess it's even less than 24W.
Realted HKEPC article : MSI 7600GS on HKEPC
It's in Chinese though, so you might want to use Babel Fish Translation
, from traditional Chinese to English.
Would the picoPSU be enough for a system like this?
I have no idea as I'm not really up-to-date about the picoPSU, all I remember is that it can provide a good amount of power on the 12V rail (as it is just more or less feeding it straight from the PSU brick), but very little amount of power on the 5V rail.
I'm sure you will find some exemples of picoPSU build in the forum though.
EDIT: ...and WELCOME TO SPCR btw !