Well, Im a programmer and I want bunch of monitors.
I have a 21.5 Inch 5K iMac, from 2017
Just bought a DUAL HDMI Adapter from StarTech.com
My intention is to have 3 extra displays because the Mac has 2 thunderbolt 3 ports so in 1 port I connected the StarTech adapter and in the other one a simple Thunderbolt 3 to HDMI adapter
But when they are connected together I have 2 random displays working, I cant get the 3 extra display to work!
In the past I have both thunderbolt ports with the single HDMI adapter and worked fine.
Im afraid that this iMac, due its 4K resolution, can't handle 3 extra monitors.
What do you say? Thanks.
Best Answer
Apple documents the supported displays now from the installed OS:
I don’t recommend using more than the official, but sometimes people are OK with adapters that split up a display if they don’t care about full resolution or refresh rates as much as maxing out the total square inches of display.
Another option is using an external GPU. See Use an external graphics processor with your Mac on Apple's website.
From your comments you should expect three 4k displays - up to 2 4K external displays and the iMac integrated one.