GTA 4 on PC.
 

Ok here's the deal. I had been playing this game on a 24 inch monitor @ 1920X1200 up until now. I purchased a 3008WFP monitor.

I had left the resolution in game at 1920X1200 while using the 30inch monitor. I noticed that after 45mins to an hour of playtime the game would crash with no error msgs. I decided to bump the resolution to 2560X1600. I didn't get any more crashes afterward but I was getting low FPS. I did a few benchmarks tests and everything maxed out I was getting 38FPS @ 2560X1600. Then I decided to keep the resolution but lower everything else to the lowest. I did another benchmark and I was getting 42FPS. There's a few videos on YT of people maxing out the game at my resolution with no FPS problems.
Specs wise I got a core I7 920 @ 4.3ghz with a Visiontek 4870x2 and an XFX 4870x2 in CF. 12Gb of ram and I use Vista ultimate x64 SP2.

I'm kinda puzzled as to why I'm not getting better performance than that because from my understanding.. Vcards like those are best at very high resolution.

Can somebody help me out?

Sorry to be so unhelpful, but it's easy, GTAIV is the worse coded pc game.

Yeah not much I can suggest either.

Make sure the game is fully up-to-date, if you're using a cracked copy maybe that's the issue. Maybe try disabling Crossfire? Or updating your drivers.

Drivers are fully updated.. and I have a legit copy. I see people playing with SLI'ed 260's 280's and 285's getting way higher FPS than me.. Guess it's time to upgrade again :S

Buy a console...not much you can do to run it better.

I have it for both PS3 and Xbox 360. It's more fun to play Multiplayer on PC.

Ya I was playing it with one of my friends yesterday and we played for like 5 hours straight and only in free play mode.

I too play in free mode. It's a great time. A buddy and I get on Skype then fire up GTA4 for some mad driving once or twice a week.

Possibly the game doesn't like crossfire? I have no clue, With your hardware you shouldn't be having those numbers. Anyways i hope you get this matter fixed!

I really think game is so badly coded that such low fps is normal even with such a computer.