Q9550: Can't get stable passed 3.4Ghz!!

Hey all!

Having trouble trying to get chip stable passed 3.4ghz. Right now its very stable at:
3.4ghz / 1.228v. Had it prime stable at 3.6ghz with 1.265v, but it would still fail during gameplay. Tried again last night to get stable at 3.7ghz / 1.300v and still could not pass prime95. Here is a list of voltages and hardware to see if anything stands out:

3.7ghz / 1.300v (447 x 8.5) (i'm thinking this voltage is plenty for the clock speed. I have never come across a C1 that needed that much voltage even for speeds of 3.8 to 4.0)
550w Antec Truepower
ASUS P5Q mobo / P45
8gb (4x2gb) Mushkin Ascent ddr2-8500 @ 2.10v (was at 890mhz, 5-5-5-18 for testing. At 400 fsb it runs at 4-4-4-12, 800 mhz)
NB = 1.30v
SB = 1.20v
volt term = auto
C1 stepping = ON

Any help is greatly appreciated!!!

Thanks!

RM

Your probably going to have to go higher on your north bridge voltage. You should trouble shoot. What I do it turn down the multiplier, but leave the fsb/ram overclocked and see if it crashes. I'm not very good at expressing myself, but it's like this, 447x7=3129. If you know at say 1.25 volts it's stable at 3.129 ghz, but your not sure if the north bridge or ram can handle the speeds you'll be isolating it as the culprit since your cpu is at a speed and voltage you know it can handle. I had to have my northbridge a lot higher than that to get a good overclock. The other way is when you run prime95, just test the cpu and not the ram.
Try giving your north bridge more juice first IMO.
I had memory errors till I went to 1.38volts on the northbridge to get to 3.6ghz, but I'm running a E8400.

FSB termination to 1.3 if you have it may help as well.

ur OC is awesome in fact.

This reference to C1 is your CPUs original core stepping right, not the BIOS referenced C1, Right?

The reason for my question is because it does take more Vcore to get where you want with that stepping of the Q9550, I have a completely different M/B than you, and I'm running my Q9550 at 3.83G rock solid P95 and Gaming.

However my Vcore is at 1.38750v.

wow that's some crazy voltage lol...

yes it's the C1 revision. It just boggles me that I can run 24 hours of prime95 stability, pass all the tests, and still get this pesky BSOD. It seems to be very stable and running great until it happens. But the fact that it only happens over ~3.4ghz leads me to believe that I am either missing something, or the testing is.

Again, thanks for the replies!

I got my Q9550 to 3.88 GHz ish, and I was using a bad motherboard (that has now about given up) I have a list of voltages I used (that I got from searching google) somewhere on my desk at home, If I remember I'll get you them when I get home today. I was cooling on water mind.

BIOS Setting Suggestions;

Load Line Calibration Disabled
CPU Spread Spectrum Disabled
PCIE Spread Spectrum Disabled

Under Advanced Tab
CPU Configuration
CPU Ratio Set as Needed or Auto
C1E Support Disabled
Max CPUID Value Limit Disabled
Intel Virtualization Tech Disabled
CPU TM Function Enabled
Execute Disable Bit Disable
Intel Speed Step Disable

Note; Manually set your DDR2 memory voltage and timings to your manufacturers specs.
Your memory may very well be your Achilles heel, it didn't seem to be that great of an OCing performer from what I've read about it, but don't let that discourage your efforts.

i overclocked my q9550 to 3.2 ghz at 1.275volt in vcore and i changed nothing just this one and it worked but i wanna know what should i do for next steps what are the voltages?

my rams are ddr2 800
mainboard : Gigabyte Ga-Ep45-UD3L



help me