Originally Posted by RonaldDumsfeld
CustomPC did a review of the Gigabyte G1.Sniper A88X board in the Jan 2014 issue. This is marketed as a audiophile quality board. (upgradable OP amps, gold plated stuff, electronic isolation, etc etc). Turns out it didn't measure any better than the standard ASUS P8Z77 they compared it too.
It is possible that their test (which I guess was an RMAA loopback) was limited by the recording quality. Most often, the reviewers simply use the line input of the tested device itself, which, in the case of onboard codecs, is rarely particularly good. Other times, they might use a high quality sound card installed in the same PC, but this kind of setup is prone to ground loop problems. Also, these reviews usually do not show how much interference is there under high system load, even though that is the most common problem with onboard audio, in addition to relatively bad (high impedance etc.) headphone outputs. In any case, it is possible that the P8Z77 already has a decent quality line output, and many of the "audiophile" features of the other motherboard might not make much useful difference.
Originally Posted by mchart
Looking at that board, while it apparently looks better then what we typically see - That shielding is still poor.
It is not necessarily shielding that is the main problem. It is quite often grounding/board layout (due to ground paths being shared, even if indirectly, with high power digital components). Power supply may also be an issue if it is not separately regulated for the codec chip.