Realtek ALC882M High Definition Audio 8-channel VS Audigy 2

Well if you are so bent on using the optical connection with your speakers or you think you'll be using the full 8 Channel setup, then go for the Realtek. However you will be giving up the following from the Audigy 2:

- EAX Advanced HD technology - Realteks only support EAX 2.0 which is pretty basic and not faithful in reproducing reverbs. See for yourself in the Sound Manager software - try out the 21 environments they give you and see how they sound very alike and overly excessive. They are certainly nowhere near customisable as Audigy 2's EAX effects. Oh and forget any EAX positional audio - the best you'll probably get is HRTF! Oh and the pitch adjustment feature only goes as far as 4 Semitones either way - not that this matters
- 6.1 Support - This doesn't seem to be an issue with you.
- DVD Audio support - Unless you get a program which supports DVD Audio discs you may not be able to hear DVD Audio Discs. Also this feature will be unusable when you use the digital output for your sound.

See what features you will miss from the Audigy 2 and if you can do without those features then auction your Audigy 2 and use the onboard solution. IMHO the Realteks have incredible features which make them so tempting to use over my Audigy 2 but then when I have to wave goodbye to EAX 3 & 4 support, I tightly clutch my Audigy 2 thinking "Why did I ever leave you?"

try the onboard and if you dont like it then put in the audigy and see if it makes a difference. Only you can listen thru your ears to know if you like what you hear.