Because I was curious, recommended specs (quick searching):

Wolf, 1992: 386, 4 MB memory, 8 MB disk

Doom, 1993: 486, 8 MB memory, 40 MB disk, Sound Blaster Pro/compatible

Q1, 1996: 75 MHz+, 32 MB memory, 128 MB disk, SBP/c, GeForce 6200 LE / Radeon Express 1200

Q2, 1997: 90 MHz+, 32 MB memory, 32 MB disk, SBP/c, 4x CD-ROM, GeForce 6200 LE / Rage 128 Ultra 16 MB

Which isn't to knock the awesome folks at id at all! Just, it was a heady time on both the hardware and software sides.