20 meters cable for displays

Maybe I can help you with that question, infriusdo.

Yes.....you could use 4 Thunderbolt screens, and use 4x 20 meter Thunderbolt cables... it

IS possible. BUT, you'd have to use active Thunderbolt cables, rather than passive ones.

There is only one company I've heard of that makes such things....Corning. They make optical active Thunderbolt cables. Not cheap though. You have Thunderbolt 2, which does support MiniDisplayPort. The maximum length of that is around 50 feet. To get that though, you'd have to go with an extender/booster. You can maybe try here for that:

https://www.avenview.com/av-extenders-c-1261/displayport-c-1261_1271/

and maybe Icron offers something like that, Thought I've never dealt with them or bought any of their products. Same goes for the previous link. I have a Mac Pro 2011

and the distance between it and my monitor is about 6-7 feet. Anyways, here's the icron link

http://www.icron.com/products/oem/kvm-extensions/cat-5e/maverick-63104-dp-and-usb-3-2-1/

maybe this might give you a few ideas

John B

You'd need a Repeater., or 2 or three..

https://sewelldirect.com/blogs/learning-center/how-to-extend-almost-any-cable#HDMI

https://www.cablechick.com.au/blog/cable-length-guide/

https://www.reddit.com/r/Monitors/comments/989lm2/maximum_cable_length_for_displayport/

This is the same problem faced in an auditorium, so some solutions will be found there as well, typically using repeaters. Then scale down for your "only" 20 meters problem.

The problem with using Analog VGA and converting twice is that by the time the signal gets to the display, it will look like garbage.

Think Bigger, then scale down for your setup.

Thanks for piping un John B. :)