Hi,
 
I'm rather new at overclocking and am on my first attempt.
 
I'm trying to overclock my 4800 x2 to 2.750 GHz with a bus speed of 220 and Multi set at 12.5.  This is being done on a Nvidia Nforce 4 chipset.
 
I've had great stability at 3.75 vcore (I can only increase by .25) when the computer boots.  I've never had an error on prime 95 with 10 hour testings, however sometimes when the computer is completely cold (I.E. not been turned on in a few hours) I won't POST.  But if i restart the computer I can boot just fine.  The computer just hangs with a black screen with all of the fans maxed.
 
I am running cool and quiet, perhaps I should disable this?  I haven't seen anything like this before in my research before attempting an OC, so I'm rather confused at how I'm getting these results.

use CPU-Z, then check if the multiplier is what you set it to, WHEN UNDER LOAD - i've heard of issues with OC'ing and cool and quiet

Done that, the multiplier fixes itself fine.  Although the voltage registeres differently then waht I have it set in the BIOS.  Could that be why I'm sometimes not able to boot?

I have an overclocked CPU 3500+ on 2.86GHz and when i try to turn on Cool 'n Quiet it can't boot up.I don't care