You can take that planned bit out of your sig if its already in
Hmm... it may help some, but with Crysis, with my card overclocked, I can't tell the difference to tell the truth much.
I can with games that use the Unreal 3 engine, for example MOH Airborne, or BioShock (around 5-10fps difference), but with the CryEngine 2 engine, I haven't so much.
OVERCLOCKING:
As for overclocking that board, Abits are amazing, I find, and very easy to configure, so I'm sure you could have it higher than it is, if your chip/BIOS is good.
I haven't needed to raise the voltage on my CPU to get my compuyter up to 3.2ghz from 2.4, but this depends soley on the board/chip in question as each one is slightly different. Not one overclocks in the same manner, and by the same amount.
What you'll need to do to basically overclock your processor faster than it is, is first to disable the ABIT's auto overclocking which it does automatically (DEL at bootup to access the BIOS)
Instead of 266mhz which is its default FSB, raising this is overclocking your CPU, whatever you set it to, higher than the standard.
The aim is to get this as high as possible without crashing your system (temps can cause this of course, but voltage can cause it, the memory too if its being pushed too hard, which also needs to be overclocked/underclocked, or not in some cases to get the system stable. Also, its the cause of the limitations of the chip, which isn't changeable of course)
The default FSB of the Q6600 is 266mhz with a 9X multiplier, giving it a clock speed of 2394mhz.
You may find that your Abit motherboard has overclocked this to around 270 something mhz which isn't going to do much at all to speeds, as Abit likes to get a slight advantage in benchmarks it would seem
I have mine to get to 3.2ghz running at a 400mhz FSB, with an 8x multplier (instead of 9, which allowed me to get 3.2ghz at 400mhz since I wanted to get the memory in sync, as its 800mhz RAM in dual channel, so its actual speed is 400mhz)
To get the speed you are going to get, get a calculator, and multiplier the fsb with the multplier, and its as simple as that.
Your first hit should be 3.0ghz, and this is rather easy to get. Simply go into the BIOS, and change the FSB from 266 to 333mhz to get you a clock speed of 2997mhz at a 9x multplier.
If you can go this far fine, make sure memory if you have 800mhz RAM, is set to 1:1 ratio, and put it to the same as me, 400mhz with an 8x multplier, and save and exit.
If overclocks don't work, most motherboards will reset automatically after a fail, but if not, most ABIT motherboards have a reset switch that you simply press, or change the jumper on to reset manually.