X48 Rampage Formula Preview.

[leo27]

To be able to lower vNB you also have to have vTT and the GTL reference voltages set correctly in addition to the CPU and NB clock skews.
Otherwise the clock skews are compensating for bad GTL votlage settings rather then allowing for an increse in stability and thus allowing for lowering vNB.

[Alien Grey]

There's also another important setting in the BIOS that needs to be adjusted. Something that we forgot it was usefull because it didn't work with the older BIOS revisions.


I'm going to explain it later and probably post the most important picture of this thread.

[leo27]

You've got me curious A-Grey whatever it is must be good since i see your q9650 clock is significantly better than whats in your sig

I might be able to get some more out of my q6600 after all

[Alien Grey]

My new 24/7 overclock.



Q9650@4.23GHz - DDR 1253MHz - tRD 6

Ai Overclock Tuner [Manual]
CPU Ratio Setting [9.0]
FSB Strap to North Bridge [400MHz]
FSB Frequency [470MHz]
PCIE Frequency [100MHz]
DRAM Frequency [1253MHz]
DRAM Command Rate [2N]
DRAM CLK Skew on Channel A/B [Auto]
DRAM TimingControl [Auto]
DRAM Static Read Control [Enabled]
Ai Clock Twister [Light] -> Here's the clue
Ai Transaction Booster [Manual]
Common Performance Level [06]
Pull-In of CH A/B all disabled
CPU Voltage [1.38750V]
CPU PLL Voltage [1.50V]
North Bridge Voltage [1.41V]
DRAM Voltage [1.92V]
FSB Termination Voltage [1.32V]
South Bridge Voltage [1.05V]
SB 1.5V Voltage [1.50V]
Loadline Calibration [Disabled]
CPU GTL Voltage Reference [0.63X]
NB GTL Voltage Reference [0.67X]
DRAM Controller Voltage REF [Auto]
DRAM Channel A/B Voltage REF [Auto]
CPU Spread Spectrum [Disabled]
PCIE Spread Spectrum [Disabled]
CPU Clock Skew [Delay 200ps]
NB Clock Skew [Delay 100ps]

CPU Ratio Setting [9.0]
C1E Support [Disabled]
CPU TM Function [Disabled]
Vanderpool Technology [Disabled]
Execute Disable Bit [Disabled]
Max CPUID Value Limit [Disabled]
Intel(R) SpeedStep (TM) Tech. [Disabled]

I have to test it for a longer period with Prime95 Blend. I did a 1.5 hour run yesterday without problems but I want it to see Prime95 Blend stable for 6 hours or more.


As you can see Ai Clock Twister at Light makes it possible to have a stable overclock above FSB 450MHz with reasonable NB Voltage and FSB Termination Voltage.
This isn't possible with any of the previous BIOSes. Changing Ai Clock Twister to Light didn't make any difference in stability because the problem was situated in the memory configuration in the BIOSes.

I was lucky that I could do 10-15 MHz above FSB 450MHz with Ai Clock Twister at Moderate. I guess that my NB clocks a little better than average.