I have just built a pc for someone who will use it for gaming, spec as follows:-

Intel QX 9770 extreme
Scythe ninja mini HSF
ASUS Extreme rampage mobo
4GB DDR3 OCZ Reaper memory
Antec 900 case
1100W PSU
Sapphire HD4870 X2 graphics
WD veloceraptor 300GB
Windows Vista home premium 64

Performance is as you might expect, pretty damn good, Vista gives it a score of 5.7 and PCmark 06 gives me about 18600.
The question I would like to ask is about overclocking the processor, the person I have built it for has asked me if I can do it for them.
Temperatures at stock speed are about 41 C at idle and at about 63 C when running prime95. If I overclock about 10%, ie to 3500 the temperature when running prime95 shoots up to about 93 C.
I checked on various sites and several people seem to be able to regularly clock to over 4000, but having said that information often seems to be confusing,on one site Intel were stating that this processor should not be run air cooled, another suggested that this processor is like the old P4 and gets very hot if overclocked, yet others don't seem to have problems with overclocking.
You may ask why anyone would want to overclock a £1000 processor, I can't answer that, you know what gamers are like.
Has anyone any suggestions as to what I can try to keep temperatures down without resorting to liquid cooling or are you of the same opinion as me and leave it at stock speed which is more than enough to play her games.

I don't know too many people who would constantly run a processor that high end overclocked. I don't see why at all.

You won't be able to push it much farther, especially on aircooling.

Did you explain to her the pros and cons of overclocking? Mainly the fact that she wouldn't be able to see ANY improvements in her games (10% OC on CPU would bump maybe 1-3 fps?)

What are you using to monitor temperatures? Software like SpeedFan and CoreTemp is not reliable. The Rampage Formula probably has an option that warns you with beeps if the CPU temperature exceeds a particular threshold. So if you don't get any such beeps after OCing and running Prime95, you should be okay. Also, what I find useful is to measure the temps using multiple programs like CoreTemp, SpeedFan, Everest, Motherboard Monitor and then taking the average. That gives you a rough idea of how the temp is in real life.

Quad-Cores can be overclocked but its generally not recommended because its practically useless.

You will likely decrease performance in games by trying to OC it anywhere, it seems to be an issue but at the same time... a Quad-Core shouldn't be getting worked up hard enough to be OC'ed, regardless if the program knows how to use multi-core processors or not.

If you really want the real temperature, get an infra-red thermometer, most sensors get unreliable at higher temperatures.

RealTempt 2.70 is the best software monitor for that CPU. just a note 93 C will kill that cpu in a short time. 95 C is what Intel says is TJmax for that processor, which means if u run it at that u will burn it up in no time. running, running prime95 it should not get above 65 C.

Thanks for all the comments, I think you have all confirmed my initial thoughts that I should leave it running at stock speed.

or just overclock until it wont do it on auto voltage. then back off one notch.