I always loved having a cable coming out of the GPU and connecting to another card. There have been many versions of this throughout my use of various expansion cards. This is excluding the SLI type of internal connections.

This made me remember of my first 3d accelerator card, the Diamond Monster 3D. It was exactly like that, a 3D-only card, that took over the 2D signal of your default video card when you activated it by daisy chaining the 2D videocard to the 3D via a short vga cable between both :-) Good times when 640x480x16bpp was enough to make me wow at something like GLQuake

I also remember my AVerMedia TV card had no way to output audio through the computer's speakers, so you'd have to take its audio out and plug it into your microphone input and enable playback of audio in.

I still to this day am not sure how the voodoo 2 actually worked with that analog link.

They used chrome-key, aka green screen. The 2D card would be told to paint an area a solid color, and the Voodoo would overwrite that section.

Pass the system’s usual video signal through the voodoo unmodified when not generating 3D graphics.

Replace the signal entirely with the voodoo’s own signal when generating 3D graphics.

Wait, what's the use case pf "connect monitor to some usb-c/thunderbolt thingy instead of just directly to GPU next to it" ?

You only need one (possibly long) cable to connect your workspace to your PC. This might be useful in cases where the PC is in a different room/far away (when using an optical USB C cable this allows distances of at least 50m), when your monitor is your USB hub or if you're simply a clean desk fetishist.

I have a similar setup, and the use case is that it’s a single USB C swap for my entire workstation setup to go from my work laptop to my gaming PC. Just a convenience thing.

Kinda shame as Displayport optionally (in theory, pretty much never in practice) supports USB over DP cable.

Could just be one DP cable to the GPU without extra fuss, like decade ago...