Quake DOS is from a year earlier to Shadow Warrior and it would get around 60fps at 320x200 on a Pentium II 266. The Xeon from that video is from 2008, and from geekbench 2 results it's ~30 times faster than the pentium. 1600x1200 is 30 times the pixels of 320x200.

Additionally Shadow Warrior used some newer rendering techniques, so it's possible they don't scale well to higher resolutions.

Sources: * https://framebuffer.io/project/quake * https://browser.geekbench.com/geekbench2/327940 * https://browser.geekbench.com/geekbench2/529270

Didnt someone have software rendering for Crysis on a third-generation Threadripper?