I can't max out GTA 4

GTA 4 is one of the most unoptimized games in the PC. You won't be able to max it with that kind of CPU and GPU.  

what kind of gpu and cpu do you recommend to max it out? It is wierd because i see many videos of gta 4 that show max setting with a gtx 460 1gb but since I overclocked my gtx 460 768mb it should be performing better than 1gb one..

Do you think my cpu is possibly making the game run slow?

Does gta 4 require at least quad core for the max setting?

Your CPU is tri-core right? If so, that should be enough since most games are optimized for tri-cores (ie. xbox360). It's probably your VRAM, 1gb is enough but 768mb might not be.

Your clock speeds might have been as high if not higher then a 1GB card, but remember that the 768MB card is missing a few things from the 1GB card.

http://www.guru3d.com/article/geforce-gtx-460-review/2

You have 8 less ROPs, and much less memory bandwidth. You would have to OC by a lot more then what the 1GB card has to make up for this. I also wouldn't say you have a tri core just like the 360 so your fine. Remember that the 360 is highly optimized with its OS and the game, and doesn't need to take into consideration the differences that can be found on the PC. Most people will say you need a highly clocked quad core AND a big GPU. Try OCing your CPU and see if/how that helps.

Unfortunately, Cutebeans is right. GTA IV is highly unoptimized. I've played it on several high-end PCs over the years and never been able to run at MAX setting with an acceptable frame rate. Hell, now I'm running a Phenom II 955 quad-core (OC'd to 3.8), Radeon 6950 1GB, 8GB of RAM, and I can't get what I'd consider acceptable FPS on less than MAX settings. Running everything on HIGH, with 8X anisotropic filtering, and no AA (not supported by game engine) I get between 25 and 35 fps while driving, and maybe 40-50 fps when on foot. The only rig I've seen able to run it at 60fps at HIGH or VERY HIGH settings was a Crossfire setup with a pair of 6950s. So, if you just have to get a silky frame rate on GTA IV, plan on picking up another 460 and going SLI.

That game wants a quad-core. It might not make it good, but it will make it better.

see if you can unlock the extra core on your 450, and consider an actual 1 GB video card.

What resolution are you playing at?

Screwy, its not really a lack of ram problem. That GTX460 is faster then the 1GB 5770. Even though it has less ram.

yes, I was't suggesting a step *backwards*. I meant a 460 1 gb, or the hd 6850 or hd 6870 or gtx 560