"System Requirements: PC compatible 386 or greater"
But unofficially, you needed a fast 486 to run it properly. On a 386 you have to switch to low detail mode and/or shrink the view area to get an acceptable frame rate.
I seem to remember having a good time with it on a 386SX 20mhz. If I am remembering correctly (I have about 75% confidence in these memories) I just dialed down the view area by a notch or two which worked well for most of the game until I got to an area with a looot of monsters.
It was pretty tolerable since quicksave and quickloads were so fast. If you stumbled into an area where you took a bunch of damage because your frame rate dropped to 5fps you could just quickload, downsize the viewport, and try again.
What's bullshit about that last one? I had a 386DX40, AMD made them, they were a popular budget option in the early 90s and the first time I played Doom was on that PC. It ran better than that video demonstrates, even at full res, though I ran it half-res and with the window downsized a notch. I presume they're using a particularly crappy video card.
That's about how I remember my 40MHz 386 playing it. At the time, it was mind-blowing anyway. I would usually play it with the window shrunk a couple notches.
https://www.mobygames.com/game/1068/doom/cover/group-1549/co...
"System Requirements: PC compatible 386 or greater"
But unofficially, you needed a fast 486 to run it properly. On a 386 you have to switch to low detail mode and/or shrink the view area to get an acceptable frame rate.