OC'ing Gigabyte P35 Assistance

[alex_oneill2006]

Hey Guys,

Could someone please get me out of this misery!

System:

e8400
Gigabyte EP35C-DS3R
Corsair XMS3 1333Mhz DDR3

I am having absolutely no luck getting the e8400 anywhere close to 4.0 Ghz like everybody else on this planet has.

When i say that i mean a stable overclock

My new RAM is rated 1333Mhz as it is Dual Channel it runs at 667 FSB. Thats all good.

e8400 @ 4.0 requires 445 FSB. No problem there either.

When I am running at Stock speeds, i.e.333 Mhz. Orthos has no problems, i ran the Blend test for 2 hours, no errors There.

As soon as i start to push the FSB higher to, let say, 400 Mhz = 3.6Ghz. T
The RAM craps out on me, and is only able to last ~ 1 min.

Anybody with good Oc Exp. or P35 exp. please can you lend me a hand, twill be much appreciated.

Regards,

--Alex

 

[Andrius]

Just a thought.
Mixed memory motherboards overclock a bit less than the single memory versions. Since you have DDR3 it's also a bit more difficult to reach high FSB frequencies. You could be reaching the FSB limits.

The general idea is to reduce possible instability variables to 1 component at a time.

EDIT: rewrite of the previous version to make it less of a mess :
Restore all settings to their default values except :
- reduce the CPU multiplier to 6 or 7 (7x445 = 3.115GHz)
- reduce FSB:RAM ratio to 2.0 or 2.4 (445MHz:534MHz)

Step 1: Verify 445MHz FSB capability
- raise FSB and (G)MCH voltages until the system is stable
(my advice is to keep voltages in the green, "safe" zone)

Step 2: Verify CPU 4.0GHz capability
- raise CPU multiplier back to 9 one step at a time and raise Vcore as needed for stability
(again stay within the green, "safe" zone)

Step 3: Adjust FSB:RAM ratio to achieve desired RAM performance
- a ratio of 3.0 should provide FSB:RAM(DDR) 445MHz:1333MHz(DDR)

Good luck.

 

[alex_oneill2006]

Dude! If only i can shake your hand.

Thank you very much for that reply, that was exactly what i did reduced the CPU multiplier.
Running at 445MHz with Orthos, and the RAM is behaving itself

Now i am going to start raising the FSB to see whats the maximum the RAM can handle so i know what my absolute limit it for future references!

In your vast experience, what would you say a suitable voltage for an e8400 @ 4Ghz is....? As previosuly i was able to boot into Windows when i set the Vcore in Bios to 1.325. But this would always fail the Orthos test!

On the otherhand, thank you very much for your advice, as it was magnificently useful to me

You really deserve a medal

Regards,

--Alex

 

[Andrius]

Well, I don't have an E8400 but I think that 1.325V should be your "current" voltage in CPU-Z during Prime95/Orthos load.

Depending on the Vdrop and Vdroop of your board and based on my P35-DS3P I would say you need about a Vcore of 1.35V to 1.375V in BIOS (mind that this is over spec for an E8400).

I hope it works out.

EDIT: I've checked some posts around the net and some need as high as 1.45V to crack 4.0GHz. I wouldn't go that high myself but that's just me.
http://www.tomshardware.co.uk/forum/245859-11-motherboard-overclocking-e8400-0ghz

 

[alex_oneill2006]

Ya i agree with you, i think for a sustainable overclock, 1.4 is a maximum!

Additionally, i am sitting around 51C on load in Orthos. What would you say would be a safe sustainable temp? I have read that 60C on load is "starting to get hot", but that number scares me hehe

And despite 1.375 V in bios i cant exactly fry the cpu? As the Vdrop and Vdroop keep the voltage below that !?

Thanks for all your help

 

[Andrius]

Regarding temperatures :
http://processorfinder.intel.com/details.aspx?sSpec=SLAPL

or

Section 6: Scale
...
E8x00: Tcase Max 72c, Stepping C0
...
-Tcase/Tjunction-
--70--/--75--75-- Hot
--65--/--70--70-- Warm
--60--/--65--65-- Safe
--25--/--30--30-- Cool

If you want further reading the quote is from here :
http://www.tomshardware.co.uk/forum/221745-11-core-quad-temperature-guide

CPUID HW Monitor should show your Tcase under one of the ITE connected "TMPINx" sensors.

Depending on your clock 51°C is a great temperature for load.
I have 55°C maximum load temperature on my overclocked quadcore at 3.0GHz.

I think you are safe under 1.45V (~10% over spec) just don't let it go to your head. For a 24/7 overclock I would stay lower but I tend too keep my systems for about 3-4 years.

You are welcome.