Multichannel PCM will be supported over HDMI.
The NUC is almost certainly not fast enough for multichannel DSD, and no PC supports DSD bitstreaming over HDMI as far as I am aware.
From your response, it seems that the statement on the wiki is incorrect then?
http://wiki.jriver.com/index.php/Id :
"Multichannel and DSD are supported over HDMI."
As I can play multichannel DSD, and DST on 4 years old Atom CPU based motherboard using MPD (granted, with around 95% CPU utilization, mostly due to the decompression), I can assure you that NUC is more then fast enough for it.
I am not sure how did the common misconception that a "PC" needs to somehow specifically support "DSD bitstreaming over HDMI", but this is not the case.
DSD is explicitly part of IEC 61937 specification, and, for the hardware part, any PC HDMI device and it's driver (a video card with HDMI) that support ANY of the IEC 61937 formats transmission, will support DSD transmission. Which is all of them.
For the audio framework part, in case of Windows, see "Representing Formats for IEC 61937 Transmissions":
http://msdn.microsoft.com/en-us/library/windows/desktop/dd316761%28v=vs.85%29.aspxWhich explicitly states the following:
"Microsoft-provided HD Audio class driver supports PCM, AC3, DTS, AAC, Dolby Digital Plus, WMA Pro, MAT(MLP) formats. The GUIDs for the compressed audio formats that are not supported by the HD audio class driver and can be implemented by third-party solutions are listed in the following table."
Which lists:
KSDATAFORMAT_SUBTYPE_IEC61937_ONE_BIT_AUDIO and KSDATAFORMAT_SUBTYPE_IEC61937_DST
Eg. any application ("third-party solution") that can be bothered to set parameters documented on that page, can stream DSD/DST to HDMI device, in exactly the same way it streams any other IEC61937 bitstream.
On Linux, situation is similar: Alsa "HDMI already supports IEC modes when you can send AC3, DTS, etc payloads without decoding. All you need to do is packetize the data in userspace and send the result over the HDMI PCM device (and set some control bits to help the receiver lock faster)." (Quote from Alsa DEV mailing list)
Which is what I expected was happening, when I saw the statement "Multichannel and DSD are supported over HDMI.".
Thanks,
Andrej Falout