Gta IV high settings without lag

[gomilly]

So i have gta IV steam playing on my current setup with 25-35 fps without shadows but when shadows are turned on my fram rate drops to 7-15 fps. What i want to know is what part of my computer is responsible for shadows and also what parts i should upgrade to get a solid 40+ fps with sadows on high/very high (low and medium look terrible).
My system specs are:
Gt 430 1gb
Core 2 quad q6700 2.66ghz
4gb ddr2 (32 bit so only 3.2ish available)
300w psu
Note: i have tried lowering all other settings and i actually get worse fps on all low and shadows off!?! Wtf? 20-27
The settings that are getting me 25-35 are:
Texture quality-high
Reflections-high
Water-medium
Shadows-off
View distance-20
Detail distance-35
Vehicle density-50
Definition-on
Vsync-on

 

[computernoob29]

Its most likely the graphics card. I would get a amd 7750 cause it takes power from the motherboard and not a cable, and anything higher then that would prob be held back by your cpu anyway

 

[Deleted member 217926]

GTA 4 is a bad console port anyway but to max it you will need new everything. CPU/RAM/Motherboard/PSU and GPU.

 

[mubin]

GTA 4 is a dinosaur. Whatever you give it, it will be hungry. You need a 7870 class video card to max it out with a good quad core cpu.