Don't forget to create backup copies of files you will modify!
1) get http://aru.nd4spdworld.com/pic/magiciv.zip Enables file modding in GTA IV.
2) after you setup MagicIV, overwrite your Grand Theft Auto IV\pc\data\timecyc.dat with modified file
http://depositfiles.com/en/files/lqzunwdt9
3) overwrite your C:\Games\Grand Theft Auto IV\common\data\visualSettings.dat with
http://depositfiles.com/en/files/jv7v87upm
it just disables bloom too, and game looks more realistic.
4) put all 90 shader *.fxc files from
Grand Theft Auto IV\common\shaders\win32_30_atidx10\*
to
Grand Theft Auto IV\common\shaders\win32_30_nv8\
with overwrite
u will see great fps
this is for nvidia user
ati user : do @ ur own risk (hope it will not fry ur card)