L1 KVM Getting Macbook Pro M1 Pro to work with DVI-D Single Link monitor

[chrishoage]

I have the two monitor USB-C PD hub hooked to a displayport monitor and a 20" Apple Cinema display via a passive single link Display Port to DVI-D adapter.

PC 1 is plugged into a Macbook Pro M1 Pro
PC 2 is plugged into a 2070 super

PC 2 can drive both the DisplayPort monitor and the DVI-D display with out issue

PC 1 can only drive the DisplayPort monitor. It will not power on the DVI-D display.

I had a HDMI to Display Port adapter laying around and I verified that the Macbook can drive the display out of its HDMI port.

However I can not get the Macbook to drive the DVI-D monitor with the USB-C to DisplayPort cables I have tried.

Is there a way to be able to allow the Macbook to drive the DVI-D display through the KVM with any set of adapters and cables?

[wendell]

@chrishoage

Is there a way to be able to allow the Macbook to drive the DVI-D display through the KVM with any set of adapters and cables?

USBc cables that are used for both DP and usb are going to have a hard time adapting to anything other than displayport.

You could possibly maybe do it via the native DP Connection part of the combo kvm but you might also need an active adapter. It Depends ™.

Glad the PC side works though.

[chrishoage]

@wendell

You could possibly maybe do it via the native DP Connection part of the combo kvm but you might also need an active adapter. It Depends ™.

Thanks @wendell! Could you please elaborate a little bit?

To provide further detail the connections currently look like this.

20" Apple Display DVI-D to DisplayPort passive adapter → KVM DisplayPort Out → DisplayPort to USB-C cable.

If I’m understanding correctly your suggestion is an Active DVI-D to DisplayPort adapter “may” do better over the USB-C Cable to the MacBook?

Or was there something I missed from your suggestion I missed?

[wendell]

@chrishoage

If I’m understanding correctly your suggestion is an Active DVI-D to DisplayPort adapter “may” do better over the USB-C Cable to the MacBook?

correct.

If you are using the combo kvm its usbc mac > usbc kvm which carries both usb and displayport; this is much more likely not to work vs usbc mac > displayport kvm > displayport out
i.e. moshi usbc to dp cable.

[chrishoage]

Thank you for the clarification! I will try with the active adapter and see if that fares any better. I appreciate your help!

[chrishoage]

To anyone coming to this thread in the future:

I can confirm @wendell’s suggestion of an Active DVI-D to DisplayPort converter allows the Moshi USB-C to DisplayPort cable to work with the Apple Cinema Display even though it doesn’t need the dual link capabilities.

I will note that switching between heads on the KVM takes a moment for the active adapter to “catch up” - about 5-8 seconds after the main display appears. Tested on both Linux with Xorg and an M1 Pro Macbook Pro. Linux is a bit slower to switch over the Apple display than macOS.

Thank you for your assistance @wendell!