What suitable upgrade?

[sa_ill]

My current config is:
E5200 2.5Ghz overclocked to 3.3Ghz
Gigabyte ATI 4850 1GB with Zalman Cooler
Gigabyte G31M-S2C motherboard
2GB DDR2 800Mhz RAM

I am experiencing terrible frame rates in GTA 4. I bought this PC a month back only for GTA4, only to find out I run it terribly, I'm experiencing terrible fps even at low settings.

What should I upgrade to bump my fps a little higher, CPU, motherboard or RAM?

 

[emp]

CPU and RAM. You could get another 2GB of memory, a better motherboard to overclock better, and a quad core CPU. Don't expect any stellar framerates though, for a game to run this bad it has to be a coding mess.

 

[NMDante]

GTA IV for PC is horrible. Period. It's not your system, it's the game.
There is a known problem with ATI 4xxx series cards, too.

Best thing to do, is play at lower resolution until there is a fix for the game.

bit-tech article

In the mean time, Rockstar is urging players to update their drivers, update their Games for Windows Live software, and to update their operating system patches. Nvidia drivers for their current cards are already available but ATI drivers will be delayed until December 10.

THG article

 

[sa_ill]

Well....I actually want to play it on full settings, or atleast somewhere close.
I have a little cash to spare, and obviously cant upgrade all the components.

Which is the single most important component that I should upgarde?

 

[NMDante]

Wait for the patch and ATI driver before buying anything.

If the patch and updated driver doesn't help, you can try CPU and memory. But if you read the bit-tech article, even high end systems are having issues running GTA IV.

These problems include glitchy textures, repeated crashes and the fact that the game won't run smoothly on higher graphics settings even with the best hardware money can buy.

But if you really want a single component to upgrade - get more memory. It's the cheapest option.