[Solved] Asus P5N-D (750i) FSB speed limit, help!

So i have a q6600 and have managed to get it to 3.26ghz. The main issue i am getting is the FSB doesn't want to budge much and the only solution seems to be cranking the HT link voltage. the NB voltage doesn't really have much effect. So far im at 1.44 for the northbridge and 1.5v for the HT link. It seems every 100mhz increase in FSB needs to have a bit more voltage. Now reading around other forums, people are hitting 1600FSB quite easily with no where near the amount of volts im putting into the HT link with the same motherboard and CPU. Do i just have a crappy board? is there something else i can do? is it safe to go beyond 1.5v for HT link? I cant find a program that monitors the actual volts for this but im suspecting that maybe its getting some Vdroop on the HT link, but i dont want to go beyond 1.5v as it seems to be quite high.........

nevermind, i found something that works. set the north bridge to auto and HT link to 1.5v. Now running sweet at 3.2 and 1600fsb with a hyper 101, getting a hyper tx3 should allow me to push it a little further, hoping to get 3.5ghz and leave it at that. Looks like putting more voltage into the northbridge was actually causing more issues than it was solving for some reason. there is also a problem with any mhz between 1450 & 1550, once i bumped it to 1600 it ran fine. Mods you can close this thread.

^like I said, its not the CPU thats the problem, its the board. Couldn't get past 3.26ghz, but could get to 3.6 no problems. there is a FSB hole with my board between 1450-1600mhz. Once at 1600 i had no issues. it wouldnt boot at 1500 or 1550, even if the NB and HT link voltages were cranked. once at 1600mhz, i could drop the northbridge back to stock volts and just leave the HT link voltage at 1.5. I have the hyper tx3 now so I will see how high i can get it, my only real option is to jump up the multiplier at run at 3.6, since any lower than 1600fsb makes it unstable. going to try that right now with some more vcore.

edit -3.49ghz now. got it down to 1550fsb and for some reason its stable on that now. I'll leave it at that since its summer now in australia and want to keep the temps safe for those hot days. 3.49ghz is plenty anyway, should keep me going for a while longer before i need to upgrade.

I dont think you understand. Everything is running fine now, I have achieved my goal. I have nailed the issue down to a quirk with my board not liking between 1450-1540mhz and NB voltage left on AUTO and HT voltage on 1.5. At 1550 FSB or higher there is no problem. The only problem I have is that I couldn't put a bigger heatsink than a hyper TX3 in my case. The hyper 212 would be touching the sidepanel of my case and touching the psu. But its running nice and cool and stable at 3.49ghz and I'm happy with that. There are plenty of people with 750i boards running very high clocks, they just have some vdroop which you can overcompensate for or do a pencil mod to some resistors. Some boards have the passive NB heatsink but mine has an active one and keeps under 40C. The SB im not worried about, no extra volts are going through it, i can touch it without burning my finger, its just warm. Like I said, problem all solved, just needed some good old fasioned perserverance and trial and error and stop reading so many tweak guides which actually caused me more problems. Its the case of every board/cpu behaves differently even if they are exact same models.