Re: Help me get to 3.0 GHz!
Well think of it as two parts. The FSB and the CPU.
The HT and the NB voltages control the ability to overclock the FSB. So anything over 1333mhz is considered an overclock for the FSB.
The CPU is controlled by the vcore. Anything over 2.5ghz CPU speed is considered an overclock. It doesn't matter if you achieve that using 1600mhz FSB with a 6x multi or 1333mhz if it's over 2.5ghz the cpu might need a voltage boost.
What you need to do first is make sure that your computer is stable at 1550mhz FSB with the 6x multi. If that isn't stable then there is no way you'll be able to keep it stable once you hit a higher CPU speed. Run OCCT, prime 95, or Intel Burn in test to see if it will hold those numbers first. If it does then try a 6.5x multi, a 7x multi, then finally the 7.5 multi. Chances are you'll need to increase the Vcore somewhere between going from 6.5 - 7.5. I'm not entirely sure but if you've proven that 1550mhz FSB works you shouldn't need to increase voltages for HT or NB to bring the CPU up.
The thing with these boards is that they have a lot of Vdrop, so even though you set your core at 1.31V in bios it might only post with say 1.29V. There is also Vdroop which is the difference between idle and load conditions so the CPU might drop slightly more yet. It's entirely likely you'll need 1.32V or more to get 2.9ghz stable. As long as your temps are okay when running a stress test you should be okay.
It might even be possible you don't need to increase the voltage of your NB that much to get to 1550mhz. If you've seen before that it likes to be at 1.28V then try those numbers to see if it will post with that. Just keep in mind that you only want to play with one variable at a time. If you change the multiple things at once then you won't know what changes are actually affecting your OC.
Another handy thing to remember is just think about what your doing in percentages. The smaller the change the more likely it will work without having to adjust other things. When playing around with the fsb 50mhz increases aren't too much of a change say 4% or less. 1/2 step on your multipler is about an 8% change. If you go from 6x right to 7.5 that's a 25% increase in clock speed. When trying to get your final clock up you might be able to do 1550 x 7 but not 1550 x 7.5 stable. What you could possibly to is try using a slightly lower FSB like 1512 x 7.5 to cut the increase to the CPU speed to smaller increments. 2710 < 2835 < 2906.