Two power supplies one soundcard

Not everybody has a $700 sound card to try dangerous experiments on.

Power never comes up instantly. "Usually" it matters if two rails come-up at the same or different times. Asus designed for "normal PC power supplies", where all outputs come from one switcher. Using two different supplies sounds risky.

Don't you have the same/similar question elsewhere?
 
But why?
Those are small loads, 100 odd mA, I would use the old or spare SMPS intended for that if needed, but only one SMPS, two together will cause all sorts of issues, particularly at light loads and different switching frequencies...

And how will it process the data outside a computer?
A sound card is intended to be used on a motherboard, I think...and the supplies will be from the computer SMPS.