On the Bethesda Blog John Carmack, Tim Willits and others share their memories of Qtest, the first public beta of Quake, on Qtest’s 14th Anniversary. Qtest was 4.1MBs of 3D awesome. This was before most people had dedicated graphic cards, so 320×200 was the killer resolution at the time. AMD and Cyrix processors of the time were not as skilled with Floating Point calculations as the relatively new Intel Pentium line, so Pentium users had a leg up on all the others.
Here are a few of the screen shots from Qtest. Remember, at this time, these visuals were pretty mind blowing. Fully 3D worlds to explore were unheard of on this level.