[trsqr]

Under win 10 EVERYTHING* (4k 8bit/10bit/60Hz decoding / HD AUdio passthrough) works as long you have no HDMI 2 device in your chain (AVR/TV).
If you have other HDMI 2 devices, then you better use a DVI to HDMI adapter. The only thing you loose is the OUTPUT (not the decoding) of 50/60Hz 4K signals....which is not that much a loss since BlurayMovies never have more then 30fps. Some Trailer have 60Hz...but how cares.

4k television broadcasts are 50Hz, so in that sense it's not totally who cares... Not too many of them around though.

You said HD audio passthrough works in Windows 10 if no HDMI 2.0 devices are present. Is that the case? With an older AV receiver it works?

Sent from my Moto G (4)