@swaaye, i tried the alternative renderers "dxd3d9r13.zip" & "dxglr20.zip" (mentioned for DeusEx in the website)earlier and definitely observed improvement compared to the default renderers that came with the steam version of the game. the original opengl renderer was better than original direct3d.
so when i used the alternative direct3d9 renderer, it was better than that of opengl, if not equal. but the minimum fps in the opening dock scene didn't cross 15 fps. i didn't try the "utglr36.zip" as i thought it was specific to unreal tournament. do you suggest using this one for deus ex?
just wanted to update that i contacted nvidia(was thinking crazy!) with a specific question "whether their graphics card have a minimum cpu requirement and specifically whether their drivers are optimized for SSE2 and such other optimizations to enhance performance in new systems(understandably)?". their revert was very quick. but as expected, they washed off their hands saying that they don't approve the pci to pci-e reverse bridge onboard the gpu, however i can play with it if it works and that the poor performance might be due to old hardware. this was even after i explained to them that the games i try to play are also very old classics. by the way they were even trying to make me understand what FPS is. i guess most of the unsuspecting user's questions get dropped into their dust bin at the customer help desk itself. so much for my 0.1% hope that it will probably reach their driver department.
i have some more stories to say later, hope i'm not bothering or boring most of you.