How is that the problem? Old PC systems were capable of running very high frame rates already, there clearly weren't any higher than this back then. At least not directly available to consumers.
for some reason i was getting better fps with dual core on my old pc(more like stable fps) + that was the only way rinput was working with et(else it would have move choppy).so thats why i force et.exe to dual
i got shit pc 2 :O 100 fps max
set higher priority to et
delete all shits that u dont need from etmain/etpro folder(demos,ss)
lower r_mode
r_picmip 3
picmip is useless fps wise since gfx cards have usually more than 32 MB Ram