The other thing though is that Original Quake Back In The Day ran on a Pentium 75 (needed the maths co-processor) with a dumb framebuffer. All the rasterising of polygons was pure software, as was all the geometry processing. Running GLQuake was a huge improvement but it required an expensive add-in card that piggybacked onto your VGA card, and a whole different binary.

Now you can just kind of pile it into a block of RAM, aim a chunky ASIC at it, and pull the trigger every frame.

In the late 90s a mate of mine did a phenomenal video of a Quake demo (you could record all player movements and camera positions as a "dem file") that he'd rendered out, raytraced in POVRay. I printed it to VHS for him as part of a showreel, and never thought to keep a copy myself.