I remember playing Doom 3 on my pc at the time, and it was like 20 fps, maybe. I also remember the marketing on PC parts at the time having stickers like “Runs Doom 3” on them.
When it came out on Xbox, one of my friends marveled at it and how good it looked on console, but was annoyed at all the pc comparisons a second friend and I were making.
I believe the real issue with Doom3 is rending more frames than 60 (per second). It results in game breaking bugs.
For anyone looking for a modern Doom 3 experience, use “dhewm3”.