Partial Build with i5 - Recycling parts?

Hey guys,

I'm looking to upgrade just my mobo/cpu/video card. I will be building my girlfriend a new rig, and figured I could simply give her the old parts of mine that I don't need, and this gives me an excuse to upgrade my system. Right now I am running a E2180 in an Abit IP35P with 8gb of Gskill pc-6400 memory. My video card is an 8800GT.

I am thinking about getting this:

CPU:
Intel Core i5-750
http://www.newegg.com/Product/Prod [...] 6819115215

MOBO:
GIGABYTE GA-P55M-UD2
http://www.newegg.com/Product/Prod [...] 6813128405

Video Card:
XFX Radeon HD 4870 1GB
http://www.newegg.com/Product/Prod [...] 6814150436

Will I see a significant boost in performance here? Should I just stick with my old LGA - 775 MOBO and buy a new processor? I want to upgrade, but don't know where I'm going to be getting the best bang for my buck.



APPROXIMATE PURCHASE DATE: This week. BUDGET RANGE: Best bang for my buck, hopefully not more than $400.

SYSTEM USAGE FROM MOST TO LEAST IMPORTANT: Gaming! Then movies etc.

PARTS NOT REQUIRED: I want to reuse pretty much everything. My PSU is a Corsair vx550w, case is an Antec 900.

PREFERRED WEBSITE(S) FOR PARTS: I usually shop with newegg, but if another company has stuff cheaper, I'm down. COUNTRY OF ORIGIN: USA

PARTS PREFERENCES: I think I want to jump on board with the i5-750.

OVERCLOCKING: Probably. SLI OR CROSSFIRE: Maybe, but would rather not.

MONITOR RESOLUTION:1920x1080

Ahh crap, I have to get new RAM too? This might end up being more expensive than I thought...

It's also possible that your current CPU is slow enough to bottleneck the 8800gt. I don't know enough about that intel CPU to be sure though. If it is you might see a boost with just the CPU upgrade.

The E2180 would be limiting the 8800GT, the thing runs at 1.8~2.2 GHz (I forgot what's the exact speed). You might want to try taking it to 2.6~3.0GHz and see if there is any improvement.

If you still ain't happy, then it would be time to buy an i5.

No, I think getting a CPU that just perfectly compliments the 8800GT then doing your build would be best. Although I have to ask - I looked at the chart and this is the 512 MB RAM version right? The 256 MB version is 3 tiers lower. Just so you have a rough feeling for it, the 4870 is 3 tiers higher than the 512 MB version.

Being an AMD guy though, I don't really know what CPU you should put into it though. I can tell you that one for 100 (and probably less) would do it without bottlenecking it.