If you had a 3dfx card it would run silky smooth on a Pentium-120 (what I had at the time)! Quake 2 ran pretty well too if I recall.

I played quake in 486dx100.

Bare minimum for it being playable was a 486DX4 100MHz or similar, but with the floating point Quake really wanted a Pentium

Ran fine on my Pentium 90 with 16MB RAM

It must have, because that's what I had in 1996 and I played it.

Quake ran on a P75 with 8MB RAM in DOS mode. Not the best but it worked at 320x200.

Quake ran well on my 100Mhz Pentium.