ASUS P5E3 Premium WiFi Overclock Intel Core 2 Quad q9550 8GB DDR3

[Thermanshs]

Greetings,
I need some help to overclock my system stable @ 3.4 Ghz 8GB Memory @ 1600Mhz . Every time I run prime95 keeps throwing errors by the first few seconds

Specs:
CPU: Intel Core 2 Quad q9550 2,83Ghz C1 Revision
MB: ASUS P5E3 Premium WiFi AP@n (uses DDR3 memory)
RAM: 2dimms x 4GB Kingston Genesis 1600 - 9-9-9-24 1.65v dual channel


BIOS SETTINGS
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FSB Frequency: 400 Mhz
FSB Strap to NB: 400 Mhz

CPU Multiplier: 8,5

DRAM Frequency: 1600Mhz
DRAM Command Rate: 2N
DRAM CMD Skew on Channel A: read below*
DRAM CMD Skew on Channel B: read below*
DRAM CLK Skew on Channel A: read below*
DRAM CLK Skew on Channel B: read below*
DRAM CTL Skew on Channel A: read below*
DRAM CTL Skew on Channel B: read below*
DRAM Timing Control 9-9-9-24 (Rest left to auto)
DRAM Static Read Control: Auto
DRAM Dynamic Write Control: Auto

Ai Clock Twister: Auto
Ai Transaction Booster: Auto

CPU Voltage: 1,30625V
CPU GTL Voltage Reference (0/2): Auto
CPU GTL Voltage Reference (1/3): Auto
CPU PLL Voltage: 1,58V
FSB Termination Voltage: 1,24V
DRAM Voltage: 1,66V (no option for 1,65)
NB Voltage: 1,45V
NB GTL Voltage Reference: Auto
SB Voltage: 1,05V
Clock Over-Charging Voltage: Auto

Load-Line Calibration: Normal
CPU Spread Spectrum: Auto
PCIE Spread Spectrum: Auto
CPU Clock Skew: Delay 300ps (read below)*
NB Clock Skew: Delay 300ps (read below)*

So, by these settings, running the small FFTs test for a couple of hours , no problems detected. When I run the large FFT tests on prime that involve more RAM testing as it says the workers report problems immediately

******
I have tried increasing the voltages on CPU - PLL - NB - DRAM to no effect. By reading this thread the guy says about tweaking the CPU + NB Clock Skew to 300ps for the FSB ratio I'm using, although the DRAM Skew controls are far too many step combinations to try!


Any ideas?

Thanks in advance

 

[Thermanshs]

oops, now I got an error in small FFT's @ 3 hrs running

 

[Bobnova]

First thing I would try is using the 333 FSB to NB strap and see if that changed things. On newer chipsets it can make a very large difference.

Something else I would do is run Memtest86+ at stockish CPU clocks, set the CPU multi to 7.5 and leave the memory where it is. You may have a dubious stick of memory.

 

[Thermanshs]

I will try reducing FSB strap again (this is my 2nd memory set, the 4GB 1333 C9 kit I used previously had the same probs)
Another question: why is SpeedFan + CPU-Z reporting different vcores than the ones I put in bios?

 

[Thermanshs]

today's results still the same, I increased cpu up to 1,4 and ram up to 1,8 . There's also no option for Ai Clock Twister - Transaction booster to disable them. I can only set Clock Twister in scales from light to strong for stability or performance and Transaction Booster has a number that has something to do with the fsb strap and it scales from 01 to 31. Lower values increase performance it says.
Anyways, the drams I think are fine because I tried different sets of them, how likely is it that I have to mess with the skews? Has anyone before oc-ed an q9550 with 8 gigs of ddr3?