I recently installed doom 3 and it wont let me set the graphics to any preset other than ultra. this is a bit much for my machine. id rather claim more frames and have unnoticeable slightly less impressive eye candy. i tried using dhewm3 but the issue persists with that also.

im running windows 11 home

did you try tweaking its cfg file? the autorun.cfg one, if my memory doesn't sleep with someone else.

I'm using Win10 and the settings menu works for me.

Have you checked the correct option(s), than clicked on "apply changes", then "exit" [game], and then restarted the game?

I tried several settings (ultra, high, medium and low) and they all worked, and all got correctly saved by the game.

With one setting (ultra in the highest resolution, I think?), I got a message, saying something like:
"are you sure? this mode will need so and so much graphics RAM and is not recommended." (I'm paraphrasing here)

I didn't try that one...but everything else "should" work as intended.

Edit:
oh...maybe this is helpful:
https://www.pcgamingwiki.com/wiki/Doom_3#Improving_performance_for_low-end_systems

sinced the settings wont stay set to what i change them to, that link doesnt help. i think disabling AA would fix it, but its back (and all the other settings revert as well) to the initial ultra settings.

Do you mean the changes you make to the config file get reverted when you launch the game? In that case, make the changes and lock the file as read only.

There is a bug where settings won't save, delete autoexec.cfg.

that worked. thanks.