I guess "chip" wise, the Vortex 2 (or AU8830) processes A3D 2.0 in hardware and little bits of A3D 3.0, whereas the Vortex 1 (AU8820) only processes A3D 1.0 in hardware, which sadly is the level also emulated by other slightly later cards such as anything by Creative (SB Live / Audigy / X-Fi). So the processing on the AU8830 is a little more unique. Do note though that 4.1 sound and digital out isn't guaranteed unless you have a Diamond Monster MX300 / Vortex SQ2500 / QuadZilla SQ2200. I was lucky and paid (a bit over the odds) £50 for a new OEM Aureal-made SQ2500 card from Russia which has the 4.1 surround + coax digital. - You may find these pop up from time to time. The Vortex Advantage (AU8810) was their final card but was designed to be a kind of high-end on-board audio as much as anything. It has a kind of mixed subset of features but depends a lot more on the CPU to do processing. I hope this helps.