[jiiteepee]

  is there any sonic advantage to disable in the bios? the reason I ask is because there are times when I just want to watch a video without having to plugging in the DAC and headphones.

 
No there aren't, if it does not conflict with other devices/controllers (some audio interfaces as like Creative's PCI/PCIe cards does not like integrated audio).
If you want it to be disabled, you can disable it through audio options by selecting option "Do not use this..." (this is much quickier path to take it into use when occasionally needed).

 

[stv014]

Quote:

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.
 

  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.

 

[imeem]

  is there any sonic advantage to disable in the bios? the reason I ask is because there are times when I just want to watch a video without having to plugging in the DAC and headphones. 

 
i leave my onboard enable just for that reason. Why would leaving the onboard enable have a negative effect on sound quality if your're using the DAC? 

 

[PurpleAngel]

  Is there any sonic advantage to disable in the bios? the reason I ask is because there are times when I just want to watch a video without having to plugging in the DAC and headphones. 

When using an external USB DAC/Amp, the sound card (on-board or add on) is bypassed anyway, so you do not have to disable the on-board audio.
If you installed an internal sound card (PCI or PCI-E), then it would be better to disable on-board audio (in the BIOS).

 

[stv014]

  i leave my onboard enable just for that reason. Why would leaving the onboard enable have a negative effect on sound quality if your're using the DAC? 

 
It should not affect sound quality, and it does not for me. Disabling the onboard codec has one potential advantage in practice: it may fix some software (buggy drivers, etc.) related problems. Usually, it is enough to make the sound card the default Windows audio device, and you can still use the onboard codec in any application that allows for selecting the output device.