stang, sound solution using AC97 codecs does NOT imply that it's a CPU hog, nor does it imply poor output quality.
The sound engine in front of the codec is where all the sound processing work is done - or not done and offloaded to the CPU instead -
and the analog fiddly bits behind the codec are what makes good or bad analog output quality.
Bad example: VIA 686B or Intel 8xx chipset integrated sound engine. Very stupid engine, lots of CPU load.
Better: SiS and ALi chipset sound engines. More brain, less CPU load.
Good: SoundBlaster Audigy. Yes this does use AC97 codecs ... but with a very intelligent sound engine driving them.
Some standalone sound chips are mixed-signal, embedding the codec. This isn't quite feasible in high density silicon like
chipset south bridges or high-end sound processors - that's why these use separate codecs, and that's why AC97 (a _bus_standard_)
exists: To unify digital output format from whatever sound engine, so that sound card or onboard sound device designers have
some choice in what they do.
The analog output quality of any of the above is mostly a matter of analog design cleanliness of the board.
(Yes this is harder to achieve on the mainboard than on a card.)
The very same thing is going on with chipset integrated LAN - you have the MAC (the digital part, the brain) as a PCI chip or integrated
into the chipset, and the PHY (the codec if you please) connected through a standardized MII interface. Again, there are PCI LAN
engines that integrate a PHY into one single mixed-signal chip.
Bottom line, saying a board has "AC97 sound" or "Realtek 8201 LAN" is as wrong as it's pointless ... because it's talking
about the irrelevant piece of equipment and brilliantly missing the important one.
regards, Peter