AMD 760MP requires 460w psu?

[Fisheagle]

I am planning on putting together a "Dualie" system when the AMD 760MP mobos finally arrive. I understand that AMD is recommending a 460w psu should be used with this chipset. I have already bought a full tower case with a 400w psu and was wondering if it would be adequate if I were to install an extra 250w psu to be used by all the case fans so that the 400w psu could be dedicated to the mobo only.

[Kuasimodem]

Ya know, I was thinking about taking the old AT power supply that I have laying around and using it to power the fans in my system (other than the CPU cooler) to take some of the load off the main supply.

I'd like to know if this would work too!