i had fps problems when i installed 1.6.4. and i just copied the configuration settings from 1.6.3., worked like a charm. This means configurating it properly makes a crucial difference.
My settings:
[GRAPHICS]
Adapter=1
Color_Depth=32
Refresh_Rate=Default
Dithering=0
Swap_Effect=1
BackBuffers=2
Interface_Status_Alpha=200
Gradient_Background=0
Compatibility=1
Antialiasing=0
Texture_Filter=2
Software=0
Bonus_Colors=1
Max_Particles=258
Bullet_Trails=1
Player_Indicator=1
Sniper_Line=0
Weather=0
Interface=Default
Smooth_Edges=0
Window_Resize=0
Screen_Width=1280
Screen_Height=720
Resize_Filter=2
Gamma=100
MiniMap_Transparency=230
Enable_Animations=0
Render_Background=1
Max_Framerate=70
Fps_Limit=1
High_Resolution_Timer=0
Scale_Interface=0
Map_Background_Color1=clBlack
Map_Background_Color2=clBlack
Force_Background_Color=0