[tlug] 2x 4K display as remote Linux desktop

[Kalin KOZHUHAROV <me.kalin@example.com>]

Hello,

I have been toying with this idea for quite some time, but finally I
have a 4K display (one) and 4K output-capable PC to start testing.
Below is a quick braindump, I'd appreciate any pointers, comments and
hands-on experience.


::: the idea
I am trying to set up a lab/analysis environment for about 12 people
(security/digital forensics), each seat consisting of 2x 4K@60Hz  40"
displays (PHILIPS BDM4065UC/11, 9man on Amazon.co.jp) and some machine
capable of driving those (via 2xDP), with keyboard and mouse
connected, possibly USB. Machines will be disk-less (PXE boot) or some
local RO media (USB) in the worst case. People will login remote
server(s) and have all their settings stored there. I remember we had
similar setup in the uni (circa 2001) with a single SunOS workstation
and X-terminals for 100 people. Of course it wasn't 2x4K :-)

::: hardware
I couldn't find any thin/zero-clients (hardware) that support even
single 4K, is that just market (lack there of)?
A simple gen4 Core Intel CPU should be fine (not planning on anything 3D-heavy).

Currently, I am thinking of Shuttle DS81 with 16GB RAM and Core i5 as box.
Alternatively Intel  NUC5i5MYHE with 16GB.

::: software
Not really a lot of research here, since most of the time I use simple
X11 forwarding via ssh to display remote windows on my local running X
session. Next on my todo list is to start using xpra.


::: network
Planning to use 1Gbps network, dual at most (10G is too expensive). My
gut feeling is that having local GB flat network for 12 people will
not be a bottleneck, but... I need to find a way to calculate (likely
test) what will video streaming look like, but ballpark figure of
32Mbps (4K@60Hz) seems good, so even 12 people x 2 displays (assuming
servers can cope) is like 768Mbps and may be fine on 1Gbps network
with single interfaces.


::: other
Mounting those 40" displays will be a bit of a challenge, but I plan
to bolt them vertically next to each other on a steel wall/partition
with a short arm and little flexibility (up/down tilt). Finding a way
to get them "below the table line" may prove helpful. Any ideas,
pictures - highly appreciated!
Given 24x4K displays, it is obvious a good challenge to make big/dense
video wall (gathering displays together) ;-) Anybody did that before?


::: some questions
1. Are you / have you used similar remote Linux desktop?
2. Any idea about required networking performance?
3. Any experience with X video walls?


Cheers,
Kalin.