i'm pretty sure its not.
I can play 24bit files through it....but i'm very doubtful that i'm hearing 24bit.
shit, the stock sound card in my Toshiba 3480ct will play 24bit files, and its a 16bit card. hardware realtime dither, i believe.
no matter.
its my mastering soundcard. i only need it to hear where I need to place tracks.