how many channels of audio can spdif carry
S/PDIF S/PDIF is based on the AES3 interconnect standard.[3] S/PDIF can carry two channels of uncompressed PCM audio or compressed 5.1/7.1 surround sound (such as DTS audio codec); it cannot support lossless formats (other than 2ch LPCM) such as Dolby TrueHD and DTS-HD Master Audio, that require greater bandwidth[4] like that available with HDMI or DisplayPort.
HDMI HDMI 2.0 increases the maximum TMDS clock to 600 MHz (18.0 Gbit/s).[110] HDMI 2.0 uses 8b/10b encoding for video transmission like previous versions, giving it a maximum video bandwidth of 14.4 Gbit/s. This enables HDMI 2.0 to carry 4K video at 60 Hz with 24 bit/px color depth.[110][111][112] Other features of HDMI 2.0 include support for the Rec. 2020 color space, up to 32 audio channels, up to 1536 kHz audio sample frequency, dual video streams to multiple users on the same screen, up to four audio streams, 4:2:0 chroma subsampling, 25 fps 3D formats, support for the 21:9 aspect ratio, dynamic synchronization of video and audio streams, the HE-AAC and DRA audio standards, improved 3D capability, and additional CEC functions.[110][113]