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Load Line Calibration

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Crazymilk

Member
Joined
Apr 12, 2006
Need some help please guys.

Im running a qx9650, i have manged to get stable at 4ghz no problem but i am confused with the volts.

Doing some research I have looked up the Load line calibration setting on my mobo ASUS Maximus extreme X38. It seesm this refers to the vdroop of the CPU voltage.

The options are Auto/ disabled and enabled. I currently have it set to auto, i have done loads of reading up on what this should (safely) be and i keep getting conflicting info.

Some sites say that using a 45m cpu you should have auto but others say that if overclocking (which of course i am and aiming for 4.2 or even higher) then enabled should be selected.

Could anybidy shed some light on this for me. I currently have the cpu volts at 1.485v in the BIOS but of course with the auto option selected the vdroop kicks in and CPUZ read around 1.4v tops when under load

I have also read that 1.4v is the max i should aim for on the 9650.

So should i have it set to Enabled or Auto?

Thanks
 

prime81

Member
Joined
Feb 8, 2008
Location
Odessa, Texas
Loadline is designed to limit vdroop to a point, but it can also be dangerous especially when your very close to ur max vcore. Loadline holds the same voltage from idle to load, but the only drawback is the voltage can spike due to overhead and can cause dangerous voltages to be shot to ur vcore. Anandtech has a review on it and I believe they were using a QX9650.

EDIT: Found the article...

http://www.anandtech.com/cpuchipsets/intel/showdoc.aspx?i=3184&p=6
 

Automata

Destroyer of Empires and Use
Joined
May 15, 2006
Well, what you want to do is enable it and then lower the vCore as much as you can. You should be able to go with a lower vCore this way :)

You won't break it if you try it. I put 1.65v through mine and did a run of 5.288 ;)
 

Evilsizer

Senior Forum Spammer
Joined
Jun 6, 2002
some have reported being stuck ocing wise with it on. not just this board but others,just FYI.
 

Albuquerque

Member
Joined
Mar 26, 2003
Location
North America

While this article is entirely correct, it only becomes a problem if you allow C1E / Speedstep to function. Those voltage spikes only come when your chip is adjusting it's own multiplier and VID to slow down...

If you have disabled C1E and Speedstep, then those transitions never happen. Which means the only reason for vDroop to exist is gone, so why keep it?

So, cliff notes: If you've disabled C1E and SpeedStep, then turn on Load Line Calibration. Otherwise, leave it at auto/disabled.
 
OP
C

Crazymilk

Member
Joined
Apr 12, 2006
yeah i have disbled C1E and speedstep so i assume i should have it enabled and i will drop the BIOS vcore to 1.35v to begin.

Does that sound like aplan??
 

Albuquerque

Member
Joined
Mar 26, 2003
Location
North America
It's at least a place to start...

I personally found that I needed less CPU voltage with C1E / SpeedStep off and LoadLine Calibration enabled. Your mileage may vary...
 

MadMan007

Magical Leopluridon Senior
Joined
Nov 28, 2001
Location
in a magical field
While this article is entirely correct, it only becomes a problem if you allow C1E / Speedstep to function. Those voltage spikes only come when your chip is adjusting it's own multiplier and VID to slow down...

If you have disabled C1E and Speedstep, then those transitions never happen. Which means the only reason for vDroop to exist is gone, so why keep it?

So, cliff notes: If you've disabled C1E and SpeedStep, then turn on Load Line Calibration. Otherwise, leave it at auto/disabled.

I think those changes accentuate it however current draw will still vary when changing from an idle to load state or back.
 

Albuquerque

Member
Joined
Mar 26, 2003
Location
North America
I think those changes accentuate it however current draw will still vary when changing from an idle to load state or back.

That's the nature of any power delivery system, and it's not unique to Intel processors, or even CPU's on a whole. Think your GPU doesn't exert a considerable amount of power draw from it's power regulation circuitry when under full load?

The "overshoot" that Anand examined and documented is the dangerous part, and that "overshoot" comes from changing voltage and multiplier when the processor is suddenly under load. The CPU doesn't "speculatively" change these, it instead waits for 100% load and then changes.

If the CPu could somehow tell the future and know that it was just about to be fully loaded, that overshoot would be FAR smaller because the load wouldn't be there yet when the VID and multiplier transistion happens.

Make sense now?
 

MongGrel

New Member
Joined
Jan 18, 2009
Location
Clearwater FL
Wow, I realise this post is really old, but was Priming and turned loadline leveling off in my bios when I had always had it on, has made things much much more stable on my OC. I think I've had the problem Evilsizer mentioned. And I've had C1E and speedstep always disabled.

I just stuck Voltage to 1.4, disabled it, then it idles at 1.36 and adjusts down to 1.312-1.328 under load.

I kinda feel dumb even posting to this one as old as it is it was one of the first one came up in a search, but seems relevant.

I'm been much more stable since I've turned it off, have been using it a long time. Seems might have been preventing a higher clock, have to see how some of these Prime's come out, that and my new fans for the CPU. The 2XNoctua NF-S12B FLX I just stuck in the back of the case are doing fantastic.

I wonder if you use it to tweak everything in solid as you can, then turn it off,then up the V-Core has an advantage. It's running everything very solid here having done that atm. Well, it was at 4.05 kicked it up a little. Might be part of the calibration part I guess heh.

:shrug:

:beer:
 
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Rich'[ard]

Member
Joined
Apr 28, 2008
Location
Melb, AUS
loadline calibration should remove all vdroop - it does in my experience anyway.
Madman007, are you saying C1E, Speedstep AND loadline calibration enabled will cause chances of the voltage spikes happening? because i have all of them turned on.

i find Loadline calibration gives you a more stable OC...without the voltage jumping around when you load it.
 

MongGrel

New Member
Joined
Jan 18, 2009
Location
Clearwater FL
Yeah was kinda my point, I'm Priming more stable with it off, and letting V-Droop do its thing. I've never had C1E or Speedstep on myself.

Go figure :)

The other posts over a year our of date I think BTW heh, silly me.
 
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jason4207

Senior Member
Joined
Nov 26, 2005
Location
Concord, NC
I haven't heard of a single instance where LLC killed a chip. I think it's perfectly safe on or off. I've had better luck w/ LLC enabled, but one should always experiment, IMO, to find what works best for their system.

On my board even if I leave speedstep and C1E enabled the CPU will not lower it's voltage while idle (while OC'd...C1E works fine at stock). It will lower the CPU multi, though. I think it's a built-in protection.