being that the MOBO uses a Via chipset whcih is not known for "Hi Def" sound, I would get the sound card.
So, let say that I don't really care about the sound "quality" but I am more concerned with the performance. Does my SB Live Platinum actually remove stress from the CPU? Or is it one of those cards that uses the CPU as it DSP? And on that note, does the onboard use the CPU? IF so, then I am definately better off using the SB card, since it will sound better.