After personal experience with it, i gotta say for the year 2000 it's deus ex.
I tried it on a pentium II running at 500 and a voodoo 3 2000 (it was a subpar build for the game i know) i think i was able to reach 20fps at 800x600
Then i tried it on a pentium III 933 and a geforce 4 TI 4200 and this was the result https://studio.youtube.com/video/SXbXYnyPuZc/edit choppy framerate and lower than expected, thinking about it, the PIII was not able to keep up with it which is a bit ridiculous if you think that the game came out when the PIII was the recommended CPU for it and the GF4 had space to spare for deus ex, i even tried swapping the GF4 for a GF3 ti 200 with different drivers but i got the same result on the same CPU
It became fluid only with my Athlon XP and 9800 XXL and well not shit sir https://studio.youtube.com/video/HjkZVHOJeB4/edit the system is way more powerful than intended for the game.
Then again the game came out in 2000 and the goty version patch came out almost in 2001 so in a way 2001 system with something like a P4 and a geforce 4 is the system to go, but it still baffles me how damn hard it is to get this game to behave on older systems, for me it's definitely the crysis of its time.