When purchasing a motherboard with built-in digital audio output, which port indicates digital audio support?

Choosing a motherboard with built-in digital audio output means you're looking for ports that can handle high-quality audio signals without conversion to analog. The S/PDIF (Sony/Philips Digital Interface) port is specifically designed for transmitting digital audio signals, making it the correct choice for indicating digital audio support.

S/PDIF is a standard interface used to connect digital audio devices, allowing for high-fidelity sound transmission. It can carry compressed and uncompressed audio formats, which is essential for quality sound components and passthrough to home theater systems.

While HDMI also supports digital audio and is commonly found on motherboards for connecting to displays, a direct S/PDIF port is specifically dedicated for audio, making it the clear indicator for digital audio support on the motherboard. USB ports can also transmit audio signals when using appropriate devices (like USB audio interfaces), but USB is not exclusively tasked with audio output in the way S/PDIF is. VGA ports are primarily used for video output and do not support audio transmission.