In my experience GTA IV won't run nicely or even decently on anything below a Core 2 Quad or Phenom X3, and to play it above medium settings on 1280*1024 you'll need a 1GB card and 4 or more GB's of RAM.
The only way I've found to get at least steady 30-50 fps is to install every update possible, disable all shadows and reduce view distance to 20, out of that everything can be on very high. Cheers Ye Olde Dell Pentium D @2.8 HT 2GB DDR RAM Intel 915g chipset @128 MB Nvidia GeForce 8400GS @512 MB The Not so Old but Unreliable New PC MoBo: Gigabyte GA-MA780G-UD3H CPU: Phenom II X3 720 Black Edition @ 2.8 no OC RAM: 2x 2GB Kingston DDR2 800 mhz PC2-6400 CL6 GPU: Nvidia GTS 250 1GB DDR3 256 bit no OC PSU: Thermaltake PurePower 80 PLUS, 700W OS: Windows 7 Ultimate Edition x64 Case: Cooler Master Centurion Black, ATX, 3 120mm Fans .C. -- 9xx SOLDIERS SANS FRONTIERS
