Possible CPU bottleneck on my 6950 ?

Hello guys!
My current setup is:
Phenom II x4 955 Be @3.7ghz
GA-MA790FXT-UD5P
4gb Corsair XMS3 Cas9
XFX HD6950 1gb @875/1350
PSU Asus 750w 80 plus certified

I want to know if my CPU is bottlenecking my 6950!
When I play The Witcher 2, I get 70+ FPS at empty areas (everything on Ultra except UberSampling, and vSync off, at 1080p), but when I enter the town square, which is rather crowded, FPS goes down to 48-55ish.
I then reduced the res to 1680x1050 on windowed mode, so I could monitor GPU usage with Trixx, and surprisingly the FPS didnt change, even with a lower resolution, and the GPU usage is about 80% at the town square, and 100% at all other (empty) areas!
All pointing to a CPU bottleneck, but, when I reduced it to 1400x900 with Low spec, FPS got to 60ish at the crowded area.. with even lower GPU usage!. Strange that the FPS did increase, i thought it was the CPU holding back since the usage was 80% and i got 100% usage with higher fps on other areas.

I was even planning to get another 6950 to crossfire, but I guess I will get a better CPU instead. Will a i5 750 @3.8-4ghz suffice? I can sell my current setup and get a i5 750 combo for almost no cost. Or should I go and get the 2500k?

Thank you guys!

No you wont be bottlenecked with that pairing. Each game is different being either CPU or GPU dependant in different degrees.

You should test with low medium and high GPU settings at each resolution to get a fuller picture of where this actual game is at its best.

Mactronix

you will not be satisfied with all the work you'll have to put into going to the i5 750
even with the best CPU, there will still be points during most games that you will see drops in FPS either due to hard drive or network latency.

but i'm a guy who change cpus only after 5+ years of use so its really up to you. for there will be a slight increase in performance, and maybe that could be worth it for you.

It's your's HDD (defrag it or buy new faster HDD/SSD) or RAM.

Also note if you are using x64 OS, 4GB of RAM isn't much for gaming rig.

From my expirience users should switch to x64 OS only if they have installed MORE than 4GB of RAM.

forgot to mention, my os and games are installed on a vertex 2 SSD, so its not HD latency

Consider my CPU the same as the P2 X4 980 (3.7ghz frequency)
Wouldnt this mean that with a i5 my fps would be much higher on these situations?

1) That video doesnt prove me WHY i need more ram, just tells me how to add it, and I surely know how to add ram to a computer (im not any kind of dummy, ive mounted dozens of systems already)
2) I already have
3) Already done as soon as I installed windows on my new SSD
4) Same as above.

I think that benchmark I posted above is pointing right to my problem: the Phenom II CPU.

Looking at your setup, I'd actually agree that it's the Phenom II CPU, given that it's the "weakest' part of your setup, and you're experiencing a slowdown when a lot of new objects are introduced into the game (CPU-heavy), not necessarily when they're being heavily interacted with(GPU-heavy).

That being said, if you want to upgrade your CPU (presumably with an Intel part, since Bulldozer is so floppish), definitely get the i5-2500k and not the i5-750. The i5-750 has an outdated socket type (LGA1156), whereas the i5-2500k uses the LGA1155 socket, which is rumored to be compatible with Ivy Bridge. Also, the -750 can overclock well, but the -2500k is a truly remarkable overclocker; with high-end air coolers (think Noctua) people have gotten 5 GHz on air, and 4.5 Ghz is an easily attainable overclock. Also, Sandy Bridge has some IPC improvements over the Nehalem architecture, so that's another plus. For gamers, the i5-2500k's the way to go.

+1
Totally agreed.......
Al-though the Hdd MAYBE a problem, But i doubt that it is.