My QX6600 G0 can only overclock to 3.35Ghz

[MobiusPizza]

I have recently just begin to overclock my system since my water kit had arrived and replaced the stock cooler.

My spec is in my sig.
My Ram is actually underclocked by setting strap and is running at 755Mhz because I prefer timing to frequency.
My RAM maxes out at just under 1000Mhz to be memtest stable at 5-5-5-15 timing. Currently it's on 4-4-4-12

I can have 8.0 multiplier and have FSB at round 420Mhz or have FSB at 372 and multiplier at 9.0.

The CPU will boot to Windows at 3.5ghz, but anything higher than 3.4 Ghz seems to fail at Prime95. My voltage is set to 1.4875V.
I am not too sure about the PLL voltage, FSB termination voltage, Vdroop control, etc so I left them at auto.
NB voltage is up a notch at 1.40V, SB I haven't touched.

I am reluctant to go to 1.50V but it should be fine with my watercooling kit. The CPU temperature is kept at 35 deg even with 100% stress tests.
Shall I up the CPU voltage and try higher?

What's the nominal overclocked frequency of these CPUs? I thought people can do higher with these with watercooling.
Thanks very much.

 

[Idontcare]

You have done the right tests to confirm your CPU is the limiting factor and not FSB or ram. So your conclusion certainly would be fair as well. Not all G0's are going to be 3.6 GHz monsters. Luck of the draw.

 

[MobiusPizza]

thanks
Guess I am unlucky then.

I would like to confirm because there is not much guidance out there explaining what FSB termination voltage, PLL voltage etc are.
I just set those to defaults and not sure whether to touch them at all.

 

[Markfw]

You need FSB to +.2, try that

 

[Duvie]

I dont believe there is a "QX6600"....no extreme editions were made for the 6600 quadcore....just a Q6600....

The X would allow you to up the multiplier and run with a lower fsb, which for some boards would be a nice advantage when ocing.....

The fact you can run higher fsb with the 8 but not with the 9 shows us that fsb is not likely the limitations...per say....I dont recall if Asus had a fsb 'HOLE" at 372 range....

Have you tried 7x multiplier and going higher then 420?
Have you tried 8x multipliet with anything in the range of 372-399? that would rule out fsb holes

 

[BonzaiDuck]

That sounds about right, although I'm comparing 680i boards to an ASUS with an Intel chipset.

The VTT voltage would probably need an increase -- Marky put his estimate right in the ballpark.

 

[krnmastersgt]

Some chips are also unable to remain stable at lower voltages, so yeah upping the vcore would be the plan, if you can get the chip stable at a higher clock then you'd lower the vcore to whatever was stable. Hopefully your chip can overclock much more.