Got a few hundred $ for upgrades, where am I bottlenecked?

[boyBlue32]

My old video card died (HD 4860) and I bought a HD 6750 to replace it, thinking I'd at least see a minor boost in gaming (Skyrim!) What I actually saw was a significant drop in FPS, especially since I can't seem to overclock as far without crashing my drivers. And now I'm upset. I could shell out for a better card, but I'm afraid it won't make a difference, because maybe I'm bottlenecked. Here's my rig:

Windows 7 64-bit
Gigabyte EP45-UD3R
Intel Core 2 Duo E7400 2.8Ghz
4 Gig DDR2
HD 6750
I'm only running in 1360x768 - don't much care about resolution, so I'm kinda surprised I can't run Skyrim at high.

Which components can I upgrade to see a significant boost in FPS in Skyrim? I also play ARMA2 which is a total beast. Both games I get less than 30 fps without resorting to lowest quality graphics. My budget is around 300. Thanks!

 

[longpig]

Have you done fresh install of windows?
It may help.
If not, look at i3-2100, H67 mobo and some G-Skill ram.

 

[tinmann]

Best upgrade for around $300.00 is the SandyBridge platform.

Core i5 2500K $219.00
http://www.newegg.com/Product/Product.aspx?Item=N82E16819115072

ASRock Z68 Extreme3 Gen3 $125.00

http://www.newegg.com/Product/Product.aspx?Item=N82E16813157271

Throw in another $40.00 for 4gbs of New DDR3 memory and we are talking $$380.00 for a really decent gaming rig.

 

[spentshells]

5750 is around as powerful as a 4850 and obviously the 4860 is more powerful than the 4850 so you have actually downgraded I am sorry about that.
For added performance you should look at a 25 dollar cooler
Your motherboard will def be able to take that chip to 4ghz or at least 3.6ghz
with a little luck with the cpu.
This should get you a lot of additional frames, it did for me in a lot of games
in some instances more than 10 frames per second taking my e5300 to 4ghz with my 5770.

This is your cheapest upgrade for additional performance