Overclocking Q9550 4.2ghz Very unstable

[SureFire]

Hi everyone, Im trying to Overclock my CPU to 4.2ghz from 4ghz and trying to get the extra 200mhz has been very hard. I can boot in to windows but I keep getting bluescreens instantly when trying to run prime 95... any help would be apreciated.

I even tried 1.42v on the vcore, and I tried 5-5-5-12, 5-5-5-15, 5-5-5-18 on the timings for the RAM. Same thing though instant bluescreen when running Prime95. I am not a pro at overclocking and I have tried tweaking many things in the bios with still no luck. Hopefully some one knows what I should be tweaking.


SPECS:

[kick]

Re: Overclocking Q9550 4.2ghz Very unstable

What you want is 495 cpu ref approximately.
You may not get it .
You are trying to overclock 4x2Gb sticks of 800mhz rated ram to almost 1000mhz.
Your memory secondary timings are tightened down as it is.tRFC of 48 is too low to be increasing memory speed.You would have to put pl (static read) out to 10 or 11 etc.
Find out the maximum speed your memory will run at with stability.
thats probably going to entail using a 2:40B or 2:66D multiplier.
You can even loosen the timings up to 6-6-6-18 to find out.
That way you can find out if your set is one of those almost 1066mhz speed sets or not.
If you cant get the memory to run at say 1040-1050mhz using a multiplier and a low fsb chances are you wont get it to 1000 with a high fsb speed.

Check out posts by ProfJim ,Acebmxer,Conners etc

and these threads:

http://forums.tweaktown.com/f69/q9550-ud3p-part-deux-quest-500-fsb-32809/#post304532

http://forums.tweaktown.com/f69/ud3p-q9550-overclock-problems-33917/

http://forums.tweaktown.com/f69/question-concerning-my-ram-q8200-37360/

[Chike]

Re: Overclocking Q9550 4.2ghz Very unstable

Your memory is DDR-800 (CAS unknown) and a lot of it, you are pushing it near 1000.
Are Advanced Timing Control set manually? If so set them auto or much looser.
Loosen Static tRead Value 10-12.
Try different straps 2 memory multiplier.
Try Driving Strength 1066.
Could be time to work the MCH Reference.
A notch higher CPU PLL may help.

Increase 8-10MHz FSB at a time with CPU Ratio 8, then add the 0.5 when RAM/FSB/MCH settings seems stable.

Search the forum for Q9550 OC threads in the forum, there are quite a few, see what others have done.

(kick was quicker but i'll post nyway)

[profJim]

Re: Overclocking Q9550 4.2ghz Very unstable

Provide a link to your memory's specifications from the Corsair website.
Try using 2x2GB of memory and see if your system is stable.
On many systems, 4x2GB will not run at full rated speed. You might be limited to 750 to 900MHz speeds with 8GB.
MCH Core that is too high or too low will cause instability or boot loop problems.
MCH Reference settings 1 or 2 clicks higher than the default 0.760 setting might be needed, where you first set CPU Termination to the standard 1.20 volt setting, then manually set MCH Reference volts, and finally set CPU Termination (VTT) to the desired setting.

[Conners]

Re: Overclocking Q9550 4.2ghz Very unstable

I'd listen to the above suggestions they are a wealth of information when over clocking. I do feel your ram will be the limiting factor though. A 500 FSB @ 2.00D means ram will be running@ 1000 MHz. Will it take it? I doubt it.

[SureFire]

Re: Overclocking Q9550 4.2ghz Very unstable

Thanks Alot for the help guys, I need to go to work and I will be back later and let you all know if I was able to get the RAM stable, and post updates. Thanks again.

ProfJim here is the link to the memory, it is the one timed at 4-4-4-12 http://www.corsair.com/products/xms2dhx/default.aspx

[SureFire]

Re: Overclocking Q9550 4.2ghz Very unstable

Well after testing for hours upon hours..., I have concluded that 8gigs of RAM can not make it that high... Also my temps are getting high without liquid cooling, at 4.2ghz so I will just stay at 4ghz for now. Thanks for the help. I think I will just upgrade to a EVGA 4- Way classified mother board, with a core i7 CPU or Xeon, and Corsair Dominator GT 2000mhz memory with liquid cooling on the CPU $1600+ lol

[profJim]

Re: Overclocking Q9550 4.2ghz Very unstable

It takes a lot of work to o/c your q9550 above 4.0GHz with 4GB or memory.
Your best (least expensive) bet is to o/c with 2x2GB of memory and when your system is stable, add the additional 4 gigs of memory and lower the memory timings to around 900MHz speeds and then adjust voltages and timings. You can then try higher memory speeds by making additional tweaks.

Good luck.