I'm currently setting up a older system in a new case (i'll be upgrading it in stages, and the old parts then go back into the old case ;p), and i'm having a bit of confusion over which cable to use, and what the difference is.
The cable looks somewhat like this , with the AC 97 connector attached to the HD audio connector. They both appear to have the same kind of connector (right down to the 'key' – the space where there's no pin and its filled up), apparently the same colour codes at close inspection and so on.
What's the difference between these cables, and when do i know what to use? In my case the sound chip is a ALC888 but i'm more interested in a generic, all purpose answer, rather than one specific to this. The header on the system itself is marked 'Audio'.
If more specific information is needed, i've put the motherboard from a dell 530 into a cosair graphite 600T, just to test the case pending the rest of my hardware.
Best Answer
The correct one to use depends on your case. Those cables are typically used to connect front panel headphone/microphone ports. While the connectors may look identical, the pinouts are different and not really interchangeable. The matching connector on your case should be labelled accordingly, I know mine is labelled HD Audio.
HD Audio is intended to replace AC'97. HD Audio is generally more capable. The linked articles have more detail on that. For average home use, there shouldn't really be a noticeable difference.
The rest of this answer will be referencing the Intel Front Panel I/O Connectivity Design Guide, page 19. They also have schematics on pages 20 and 25 if you care. I will be adding emphasis.
Some sources indicate that it is/may be necessary to switch audio output modes in the BIOS configuration or with a jumper. It is recommended that you look at your motherboard manual. My own motherboard (MSI P67A-C45) manual just says it's compliant with the Intel Front Panel I/O Connectivity Design Guide, not all that much information. Dell manuals describe it as
front audio (F_AUDIO)
and don't indicate any such jumper, and only describe the BIOS optionOnboard Audio Controller
asEnabled or Disabled (Enabled by default)
.