On Fri, 20 Oct 2017 16:17:37 -0000 Helmut Jarausch wrote:
> Hi,
> I'm considering buying a new monitor (and graphics card) which supports
> 10 bits per color channel.
> Will Gimp on a Linux machine (X11) support this now or in the near future.
> Or is it just waste of money to buy a monitor with more than 8 bits/color channel?
> Many thanks for some hints,
> Helmut

Linux and Gentoo in particular supports 10 and 12 bits per channel.

But in order for this to work you need to have support from all
chain, both hardware and software:

application -> de/wm or rendering stack (gtk/qt) -> xorg (supports)
-> video driver (see below) -> video card -> cable(! ) -> monitor

You have not told us what is your video card, but at least Intel[1]
and nVidia[2] products support 10/12 bits in Linux.

Definitely not all application support deep colour (10/12 bpc), but
most multimedia oriented do: gimp, ffmpeg, mplayer, mpv...

You may encounter some problems with GTK apps, though the proof
links I found[3,4] are quite old and situation may have improved.

Also take a note that 10 bpc imposes some limitations on the screen
resolution depending on your connectivity[5].

[1] https://communities.intel.com/thread/101627
[2] https://nvidia.custhelp.com/app/answers/detail/a_id/3050/~/how-to-enable-30-bit-color-on-linux
[3] http://www.oyranos.org/tag/30-bit/
[4] http://darktable-users.narkive.com/ndONjycG/anyone-with-30-bit-color-depth
[5] http://bilder.hifi-forum.de/medium/262100/hdmi-20-597x266_609346.jpg

Best regards,
Andrew Savchenko