Dell D3818DW: How to connect KVM between PC and Macbook pro mid-2012?

Question

I just bought a Dell 38" Ultrawide (D3818DW) and I wanna get all the cables I need while I wait for it to arrive. I want to use the KVM feature of this monitor between my MBP mid-2012 and my PC so I can switch seamlessly between them.

I've read that I need a Mini-Display Port to Display Port cable to connect my MBP. And to use the KVM feature, I have to also connect a USB downstream cable to the MBP.

However, I also read that connecting a MBP via USB-C can bypass having to connect a USB Downstream to use the KVM feature. My Mac has a Thunderbolt 2 port and two USB 3.0 ports.

So, can I just use something like the StarTech TBT3TBTADAP TB 3 to Legacy TB adapter for display and KVM? So I won't have to have two wires sticking out of my MBP when using the KVM feature.

Answer 1

So, can I just use something like...a TB 3 to Legacy TB adapter for display and KVM? So I won't have to have two wires sticking out of my MBP when using the KVM feature.

No. This cannot be done. Thunderbolt 3 is backward compatible with Thunderbolt 2 and 1. It cannot make a Thunderbolt 1 or 2 port suddenly Thunderbolt 3.

Thunderbolt is backward compatible not forward.

I also read that connecting a MBP via USB-C can bypass having to connect a USB Downstream to use the KVM feature.

The industry has made USB-C very confusing. Basically, it's not if you have a USB-C port, it's if your computer supports USB v3.1 which uses a type C connector. The USB ports on your existing Mac are 2.0, so it will not work as a single cable solution. You'll need both the DisplayPort and USB downstream cable.

Answer 2

No, that product cannot be used for this purpose as it does not transfer the actual display signal (i.e. what would be called Alternate Mode in USB-C), nor is it for connecting newer TB3/USB-C devices to an older computer - it is actually for connecting old TB/TB2-devices to a new TB3 computer.