2015-12-30, 11:35
(2015-12-23, 02:06)Möhre Wrote: I am wondering why you guys bother about the HDMI port... I am still using gen4 NUC with ~9€ DP to HDMI cable which works totally fine.
But your adaptor converts Displayport to HDMI 1.4 - or more accurately doesn't do any video conversion, but instead sends a signal to the GPU to output HDMI over the Displayport connector pins which is remapped to the HDMI pins by the converter. This is limited to HDMI 1.4 bandwidths, and the HDMI implementation in the GPU. This means with an Intel GPU you are limited to 1080p/60p or 2160/30p resolutions.
The interest in DP to HDMI 2.0 active conversion is to allow 2160/60p output from a Skylake NUC. However the NUCs still have HDMI 1.4 outputs so are limited to 2160/30p (Intel don't implement the 4:2:0 2160/60p HDMI 2.0 mode that can be carried over an HDMI 1.4 connection, which was nVidia's trick to get 2160/60p over a legacy HDMI 1.4 bandwidth connection) This means that the Displayport output, which does support 2160/60p, has to be converted.
However the Displayport outputs don't support 2160/60p when running in "HDMI over DIsplayport" mode (i.e. what happens with a €9 connector), and instead needs an active converter that allows the GPU to stay in Displayport mode, thinking it is connected to a Displayport display, but with the converter doing the clever Displayport protocol to HDMI 2.0 protocol conversion. This is a non-trivial function, and devices have taken a good while to appear on the market. I've still not seen a decent review of one...
There is a lot of confusion about how Displayport works with cheap HDMI converter cables. The simple fact is that it stops being Displayport and becomes HDMI (just not on an HDMI connector)
