Originally Posted by coolpurplefan
What about the 720a and 730a? Is it true that some of them don't have good on-board sound?
The full name of GeForce 8200/8300 is "GeForce 8200/8300 and nForce 730a" (it's a single chip, but is called as if it were a two chip solution). nForce 730a/720a is a cut-back version of "GeForce 8200/8300 and nForce 730a" without onboard video. Summary is here
The HD audio controller built in these chipsets are exactly identical. The difference appears only with third-party audio codecs (ALC888, ALC889a etc.), but only when you use analog, there is no difference if you use digital (S/PDIF).
BTW if you use a Radeon card, it has its own HD audio controller (7.1 ch with HD 4xxx), independent of that of the chipset. GeForce card lacks it so that it supports only S/PDIF pass-through from the onboard audio codec.