[prestontrogden]

which one is better for 5.1? i notice my headphones using AC97(onboard) seem to sound a little richer.

 

[Rakukojin]

The VIA Envy24 supports 24-bit sound while the AC'97 only supports 16-bit/20-bit sound. Audio resolution doesn't mean everything but the VIA Envy24 is superior to the AC'97.

 

[lenzo]

When gaming, my old AC97 sound wasn't cutting it when facing a character who was speaking to me (HL2). As I would turn, the voice would diminish and sounds behind me were not clear/distinct. I got a Soundblaster 7.1 card and got a slight improvement but I'm not happy like I used to be with my last Audigy 2 ZS quality.
The Soundblaster 7.1 also pumps out too much heat!!!!!!!!!!! Just unreal.
I'm gonna soon try the X-Fi as soon as this Alaska winter is over (but will use the current SB7.1 to heat my room for now).