Comment by bzzzt
16 hours ago
I had that setup working back in the day with a Voodoo1 which had the pass-trough construction to take over full screen: only on Linux you could read the completed frames and render them in an X window. It was dog slow though.
While transfers have improved a lot the amount data needed for 4K60 with HDR is about 18Gbps. There's no way that doesn't have an impact.
We cooked up a setup where we had a PCI video card for X, and a separate Voodoo 1 or 2 and monitor for 3D (Mesa) rendering. I don't remember the details any more, but it was nice to not take out the desktop when someone borked up their OGL homework.
the voodoo1 worked differently as you looped through the video input. The voodoo banshee i mentioned was a separate 2d/3d card (it actually was 3DFx first true, combined 2d/3d card - not an accelerator).
I know. Voodoo 1 and 2 had the ugly VGA passthrough hack. But the principle of reading VRAM from one card and copying it to another would remain the same I think.