Excellent gaming computer giving very low performance HELP!

Hey whatsup guys I really need some help here. My computer which was custom built for gaming is getting horrible Fps or not what it should be getting. Heres my rig.

Processor:
Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz (4 CPUs), ~2.4GHz

Memory:
4 gigs of 6400 channel ddr2 ram

PSU: Raidmax RX-630wSS

Hard Drive:
320 GB

Video Card:
NVIDIA GeForce GTX 260 Core 216 Superclocked Edition

Operating System:
Windows Vista™ Home Basic (6.0, Build 6002) Service Pack 2

Motherboard:
ASUS P5N-D

Im getting the following fps in these games:

Crysis Warhead:
Lowest (idle: 32 fps Busy: 23-30 fps)
Gamer: (Idle: 28 fps Busy: 15-25 fps)
Overclocked GPU + Enthusiast (Idle 19 fps Busy 10-15 fps)

World Of Warcraft:
Lowest (idle 35-40 fps Busy 30-40 fps)
Highest + overclocked GPU (idle 38-42 fps Busy 31-40 fps)

Garrys mod/ Half life 2
Lowest (idle 40 fps Busy:31-39 fps)
All max (idle 36 fps Busy 28-36 fps)
All Max + Overclocked GPU (idle 38 fps Busy 30-39 fps)

I also own 3Dmarkvantage and i got the following score (Overclocked GPU)
12357 overall points
10350 GPU score
21157 CPU score

I really dont know what to do and i really hope someone will help me out here. Thanks.

PS: Just incase you missed it somehow I DO overclock my GPU somewhat high (720-730 linked core clock and 1120 memory clock) but I DO NOT overclock through BIOS i use EVGA precesion 1.7.1. My MOBO is never overclocked niether is my memory.

PSS:I do have the latest drivers installed the only thing im questioning is my nForce drivers but idk if i even need the new ones because i dont use SLI. My temperature on my GPU never goes above 62c My Mobo never gets above 40c And my HDD never gets above 30c. I dont think temperature is the problem.

I run AVG, Ccleaner, and Speeditup free every day. Ive never had any infections on this computer just cookies.

Im playing at 1280x1024

Maybe the GPU is the problem, is you do overclok and the problem continuos....go to the seller and check the GPU....maybe is the problem.

if you have the evga gpu rma it as they had a problem with their 260 superclocked editions

i honestly dont know if i should overclock it i dont know how and also idk if my cooler could handle it. also here is some more info about what im doing/running.

Ive been thinking about getting either home premium x64 Or windows 7 but i really dont know about windows 7. Isnt there some way to get it free right now? I honestly dont know how to switch my OS without deleting everything or seriously screwing stuff up. Someone said something to me about using task manager to check the affinity for games since i have a quad... can someone go more into detail about that?

ALSO My clocks are set to default using the following Hz:
Core clock: 626
Shader clock: 1350
Memory clock: 1053

When idle:
Core clock: 301
Shader clock: 602
Memory clock: 100

Also I just remembered i DO use the AISuite provided by ASUS and i usually keep it on turbo mode for gaming. I dont know exactly what it changes if anything but i wonder if that could be it?

A Q6600 should be able to safely do 3.0-3.2ghz with stock cooler. I would not try for anymore than that though.

I am not all that familiar with Asus bios. But basically want to set your ram to where it runs at a 1:1 ratio @ stock first. In your case that would be DDR2 533. Then up the bus speed in small 5mhz increments. You should be able to get 3.0 I would think with that chip without voltage increase unless it is a B3 stepping. I did not think of that earlier when I made my statement. B3 stepping Q6600's run hotter than the G0's. Check the stepping. Go in small amounts of overclock and run core temp to check your temps under load. If still OK then keep going.

Then I suggest you go to the overclocking section or do some google searches on how to's.

M_L, you'll need to start your own thread.

btw not everyone gets their q6600 about 3.4 btw

only people with good overclocks brag about it, while people with average overclocks don't tell a soul

I have a 3.1ghz overclock and sadly its my max, its not a temp problem
I've even had my processor eat 1.55V to make it run at 3.2 stable

I lost the chip lottery, just hope you didn't