Does my Mac support 'DisplayPort Alternate Mode' so I can use a KVM?

Question

I'd like to buy a new monitor and have been looking at models that have an in-built KVM switch functionality as this would both reduce cabling/connections and enable me to use the monitor for home and Work-From-Home easily. I'm aware I could get a separate KVM, but one that's already in the monitor seems ideal.

I have a home MacMini (2020, M1) and a work MacBook Pro (16" late 2019, Intel). Both have USB-C connectors with Thunderbolt 3 which both state:

Native DisplayPort output over USB‑C

in the technical specs (linked above).

I'm aware that I may need specific cables such as Apple Thunderbolt 3 (USB-C) Cable

Before buying the monitor, is there any way to verify that at least one of the Macs has the required feature/signalling to communicate to the monitor so that it can use the KVM feature?

This whole question was brought up by a review of the monitor which mentioned the DisplayPort Alt Mode issue.

Answer 1

Yes, both the 2020 M1 Mac Mini and the 2019 16" MacBook Pro supports DisplayPort Alternate Mode. All Thunderbolt 3 ports (as those on those Macs) supports USB-C Alternate Mode for DisplayPort.

Note that often I see that monitors with built-in KVM have non-obvious drawbacks or "things that might annoy you". You need to think your use case through and do testing to figure out if it does everything you want. For example you might find that the automatic switching of keyboard/mouse doesn't work as you want it to, or that the monitor has difficulty dealing with computers that go into sleep mode, or similar problems. This is not specific to Apple computers - it is general issues that come into play with any type of computer.

Answer 2

My testing cases showed the monitors with a built-in KVM switch function will have many issues with your setup profile for I have 100% same hardware profile as yours (M1 Mac Mini and 2019 MacBook Pro 16 -the intel-based).

I recommend using an external KVM switch solution for your setup profile.

1. Pick any DisplayPort monitor without built-in KVM switch function or without PIP (picture in picture) or PBP (picture by picture) as your sharing monitor. It's much cheaper and relaible.
2. Just using an active type-C-to-DP cable and USB-A-to-USB-B cable connecting between your M1 MacMini and the DP KVM switch.
3. Just using an active type-C-to-DP cable and USB-C-to-USB-B cable connecting between your MBP and the DP KVM switch.
4. All sharing monitor(s), keyboard, mouse or other sharing devices can be plugged in the console connectors of the DP KVM switch.

** If you want to have an ultima solution, then you can add a docking station between M1 MacMini and KVM switch, and one docking station between MBP and the KVM switch. The ultima solution can provide single cable connection to the both of your M1 and MBP via just a Thunderblot 4 cable.