E6400 3GHz stock voltage--not stable?

[Dolorous Dave]

So, my E6400 on a DS3 mobo is not at all stable at 3Ghz on stock voltage. I seem to fail Orthos around 2-3 hours each time.

I'm not comfortable raising the voltage on the CPU yet but I've read in numerous places that the E6400 should get 3GHz on stock voltage without problems. Any ideas what I'm missing here?

My memory is on a 2 divider, so it's running below spec at 750Mhz instead of 800Mhz--that can't cause a problem, can it?

I'm getting load temps of around 45C with an Arctic Freezer Pro7, so overheating can't be the problem.

I have my memory volted at 2.0V for the GSkill I'm using, the mobo starts it at 1.8V which is too low for that memory.

So I'm out of ideas. I really don't want to raise the CPU VCore if I don't have to.

 

[GuitarDaddy]

At 375 x8 your pushing towards the top of the 1066 strap for internal timings, you need to up the FSB/chipset/NB voltage (not sure what its called on your motherboard). 370-400 is a rough spot to make stable on most P965 boards.

I would recommend jumping to 401fsb which will get you on the 1333 strap, you can likely do this on stock chipset volts and maybe even stock vcore, or maybe a slight bump in vcore

 

[Dolorous Dave]

Please explain this "strap" you speak of, for it makes my brain want to explode into little tiny bits.

 

[Duvie]

I doubt he will be able to do 8x401 at stock voltas....Most cannot....It usually has been taking 1.4v-1.42v set and loads to 1.36-1.37v.....


I would say Dave I think you are in need of a voltage boost.

have you tried rasing the vfsb up any? How about the vmch? I would try giving those a boost of +.1v.....

Also as the board gets OC's seometimes even if you are not running stock specs on the ram it may require a boost of .1v as well....especially when in dual channel mode...


Simple test and wont hurt anything is to raise vfsb and vmch by +.1v....Then test it again.

 

[Dolorous Dave]

I haven't tried upping the vFSB or vMCH yet so that will probably be my next try before upping the CPU voltage. I'm also a little nervous about the options in the BIOS that appear to slow the CPU down at times the mobo thinks it important?

 

[GuitarDaddy]

Originally posted by: Dolorous Dave
Please explain this "strap" you speak of, for it makes my brain want to explode into little tiny bits.

http://www.thetechrepository.com/showthread.php?t=30

 

[Dolorous Dave]

Originally posted by: GuitarDaddy

Originally posted by: Dolorous Dave
Please explain this "strap" you speak of, for it makes my brain want to explode into little tiny bits.

http://www.thetechrepository.com/showthread.php?t=30

Would this explain why as I ramp up the FSB, my PCMark05 scores can vary from 7400 to 6200 for no reason whatsoever? Like, at 3.2Ghz I get 7400, at 3Ghz I sometimes only get 6300ish.

hell, it might also explain why, at exactly 400MHz FSB, Orthos errors out immediately on starting. The memory might be freaking out.

 

[GuitarDaddy]

Originally posted by: Dolorous Dave

Originally posted by: GuitarDaddy

Originally posted by: Dolorous Dave
Please explain this "strap" you speak of, for it makes my brain want to explode into little tiny bits.

http://www.thetechrepository.com/showthread.php?t=30

Would this explain why as I ramp up the FSB, my PCMark05 scores can vary from 7400 to 6200 for no reason whatsoever? Like, at 3.2Ghz I get 7400, at 3Ghz I sometimes only get 6300ish.

It's possible, I'm not sure about PCMark05, but it's definately proven that memory bandwidth reduces once you pass 400 and hit the 1333 strap

hell, it might also explain why, at exactly 400MHz FSB, Orthos errors out immediately on starting. The memory might be freaking out.

More likely the NB, it's pushed to the limit at this setting and would likely need quite a bit nore FSBv to get stable

 

[Dolorous Dave]

ok, I'll definitely try bumping the vFSB .1 when I get home tonight. I've been keeping it down at 3Ghz because of the immediate error-out on Orthos at 3.2Ghz. But I'd love to run it at 3.2Ghz if I could just get it stable, especially if I'd be eeking much more memory performance out at that clock speed.

 

[GuitarDaddy]

I'll bet you can find stability at 401+ if like Duvie suggested you up the vcore to 1.42 or so. Most E6400's seem to do 3.2 orthos stable with a small vcore bump.

 

[Dolorous Dave]

that's the thing, the DS3 doesn't tell you WHAT the VCore is, it just tells you how much you've bumped it so I have no idea where to start.

 

[Duvie]

I believe cpu_z as well as gigabyte's Easy tuner app will show you actual vcore.

Go to 401fsb

set vfsb +.1v
set mch +.1v

set vcore to 1.4v-1.4125v...It should idle when you enter windows at 1.39v...under load it likely will drop to 1.37-1.38v....

 

[Dolorous Dave]

Originally posted by: Duvie
I believe cpu_z as well as gigabyte's Easy tuner app will show you actual vcore.

Go to 401fsb

set vfsb +.1v
set mch +.1v

set vcore to 1.4v-1.4125v...It should idle when you enter windows at 1.39v...under load it likely will drop to 1.37-1.38v....

Ok, this is exactly what a retard like me needs. Thank you thank you thank you. Is 1.4V going to idle a whole lot hotter than 1.20Vish (which is where it hovers now, I think)

Also, the memory should be fine with a divider that makes it run at 800Mhz, right? I mean, that's the memory's speed after all...

 

[zagood]

I don't think you're going to need that much voltage, but do what you have to do. Stock is what, 3.25v? I bumped my e6400 up to 3.75v, then steadily worked my way down, I'm at 401fsb with 3.31v.*

There are two settings between 3.10 and 3.2v, I can't remember which one I have it set at, but you get the idea.

Anyway, feel free to start high, but work your way down the vcore selections. You'll see a big difference in heat output as well.

-z

 

[JAG87]

yes, 3v through a core 2 duo. man id like to see that.

:camera:

 

[Dolorous Dave]

Hopefully he means 1.10 to 1.2V?

 

[zagood]

lol...whoops. Move decimal point over one space and add a 1 in front...

1.325, 1.375, 1.331 etc.

-z

 

[Dolorous Dave]

ok, so with the memory volted to 2.0V, I can boot into Windows just fine at 3.2Ghz at stock voltages with a 401FSB. Running Orthos now to see how stable it is. Is it POSSIBLE I'll be able to maintain this speed without updating the CPU voltage? I'd love to keep the lower heat output if possible. FSB and MCH volts are at stock as well. Maybe it was just the strap I had to get past?

 

[Alone]

2.0V? I would suggest against that...
1.37x is a sweet spot for most overclocks, especially since you're not pushing it far.

I got 3.36 stable out of my E6300 on 1.3x and higher.

EDIT: You might also want 2.2 out of your memory, (vDimm?). Most are around 1.8 stock, so a +0.4 would be more than enough. If it's 1.9 stock, +0.3.

 

[Dolorous Dave]

Um, that's 2.0V on my memory, not my processor. I'm asking if I can get away with no overclock on the CPU.

 

[Dolorous Dave]

up to an hour stable on stock at 3.2Ghz with only memory overvolted, everything is stock voltage. Let's hope it holds!

 

[Dolorous Dave]

aaaaand it just errored out, upping voltages a bit

 

[bfdd]

edit

 

[Dolorous Dave]

So, I upped the CPU voltage 1.33V-ish and under full load, CPU-Z is only showing the voltage at 1.264V--is that normal? I also raised the FSB voltage and the MCH voltage by .1V each. I hope that's not dangerous in some way...

 

[RichUK]

CPU-z has a bug where it does not display the voltage properly, so this it is quite inaccurate for reading the Vcore.

You should have some monitoring software bundled with the motherboard, most likely located on the driver CD which should allow you to accurately read the Vcore value.