http://en.wikipedia.org/wiki/S/PDIF *S/PDIF can carry two channels of uncompressed PCM audio or compressed 5.1/7.1 surround sound (such as DTS-HD High Resolution Audio) with a maximum bandwidth of 3.072 Mbit/s per channel for a total of 6144 Kbit/s; it cannot support uncompressed lossless formats (such as Dolby TrueHD and DTS-HD Master Audio) which require greater bandwidth like that available with HDMI or DisplayPort.
而且在電腦上以後應該會轉到以通過顯卡的 HDMI 為主 (傳輸 bit rate 上限較高) HDMI 2.0: Up to 32 audio channels, (or) Up to 1536kHz audio sample frequency
HDMI 1.x Max audio throughput Mbit/s: 36.86 HDMI 2.0 Max audio throughput Mbit/s: 49.152