I have a few issues with GTA 4 on my system as well but the main one may be caused by the Radeon driver for the Diamond HD-5770?
My PC
MSI NF750 G55 Motherboard
AMD Phenom II X2 550 3.1GHz CPU
G Skill 4GB DDR3 1333 Memory
Diamond HD-5770 128bit 1GB DDR5 Video Card
I am playing the game at 1080 X 1920 and once in a while it gets a little slugish and if I am killing a good number of people or blow up a certain number of cars. People or cars will start disappearing from the screen like it doesn't have enough memory. I do not have all the details turned up to max so I have also wondered, what does it take to run this game at max settings?
My first 5770 Radeon card was defective and I am now on my second 5770 Radeon card and I am ready to ditch it and get a different card!!! I am looking at 256bit GTX - 460 video card with ether 1gb or 2gb of DDR5 memory. I am also considering upgrading my CPU to a AMD Phenom II X4 965 3.4GHz Quad Core. If I upgrade my OS to the 64bit version I will upgrade from 4gb of DDR3 memory to 16GB of DDR3. If I need to I will save up for a new GTX-590 EVGA with 384bit 2GB DDR5 and dual GPU's. And then I will have to upgrade my power supply.
So what does it take to run this game at max settings?
What does it take to run Crysis 2 or Home Front at max settings?
Funny thing is a built a AMD Phenom II X4 965 3.4GHz, 8GB of DDR3 1600 memory, MSI 870S-G54 motherboard and a MSI N450GTS Nvidia and it handled games better than my pc. My PC wouldn't play Mafia 2 demo at all and this other PC would!