Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

[snowcake]

Hello,

Recently I buyed the Asrock H77M motherboard. There is something what confuses me.
I suppose that most of you guys(girls) know what LLC (Load-Line Calibration) is.


If you click on the link below this line and click on: OC Tweaker: Voltage Configuration, and read the CPU Load-Line Calibration section...
Complete Overclocking Guide: Sandy Bridge & Ivy Bridge | *ASRock Edition*

[Conners]

Re: Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

I really don't know but asuming say 100% is zero droop in voltage and your not using any cpu offset voltage I would say that's about right.

For example using mu GB board if I set Vcore (CPU Core Voltage) to Normal, I can then use DVID offset (CPU Voltage Offset) and then set my Load Line Calabration (CPU Load-Line Calibration) any where from Auto to Extreme like six settings( yours 0-100%) So say I set my vcore to normal (not sure what you setting is) and set DVID offset to say a +20 and my LLC to extreme ( and well say that will equal yours @ 100%) So what thar basically means is by selecting a higher level or % it will keep the Vcore (CPU Core Voltage) more consistance with what the Vcore is set to in the BIOS when under load. In other words very little change in voltage. On the other end a 0% would allow the voltage to droop (drop more) and woulf there for require more DVID offset ( CPU Voltage Offset) to achiece the same voltage as the higher LLC.

Clear as mud right!

[parsec]

Re: Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

snowcake, IMO, your analysis makes sense. 0% LLC should mean nothing is done to compensate for a voltage drop of Vcore. 100% LLC should mean Vcore is maintained regardless of load (in practice, as much as possible.) IMO, the values between 0 and 100% are meaningless, since what does maintaining Vcore by 50% mean, for example. Those setting levels just provide less compensation as Vcore rises, which is fine, but the amount is arbitrary.

My ASR Z77 board had a BIOS/UEFI update recently that included, "Modify CPU load line calibration behavior." That might be a fix for the situation you seem to have identified, but I'm not sure as I never checked Vcore vs load at various level settings of LLC, as you have done.

In my board's UEFI, there is a graph displayed when LLC is selected, that shows how much each setting level will maintain Vcore. The levels are also not shown as %, but just 1 through 5, with 1 being the highest (100%), and 5 being the lowest (0%.) You might think that 5 is greater than 1, so 5 is the most LLC, but it is not according to the graph.

I must say that in my OC testing with my ASRock Z77 EX4 board PC, I never had a problem with Vcore being low. I say that because I am surprised by how much your Vcore dropped under load, and to tell you that may be related to other settings that you and I use that are different.

Are you using a fixed, manual Vcore setting? I don't, I set it to Auto. If I did, I might get the drop in Vcore that you do, but I've never tested that. Right now, I am OC'd to 4.5GHz, with SpeedStep disabled, so it is constant, and my idle Vcore is ~1.256V. Vdroop really is unknown unless you use a set Vcore, which I don't, but I don't use full LLC, and I have good CPU cooling.

[snowcake]

Re: Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

snowcake, IMO, your analysis makes sense. 0% LLC should mean nothing is done to compensate for a voltage drop of Vcore. 100% LLC should mean Vcore is maintained regardless of load (in practice, as much as possible.) IMO, the values between 0 and 100% are meaningless, since what does maintaining Vcore by 50% mean, for example. Those setting levels just provide less compensation as Vcore rises, which is fine, but the amount is arbitrary.

My ASR Z77 board had a BIOS/UEFI update recently that included, "Modify CPU load line calibration behavior." That might be a fix for the situation you seem to have identified, but I'm not sure as I never checked Vcore vs load at various level settings of LLC, as you have done.

In my board's UEFI, there is a graph displayed when LLC is selected, that shows how much each setting level will maintain Vcore. The levels are also not shown as %, but just 1 through 5, with 1 being the highest (100%), and 5 being the lowest (0%.) You might think that 5 is greater than 1, so 5 is the most LLC, but it is not according to the graph.

I must say that in my OC testing with my ASRock Z77 EX4 board PC, I never had a problem with Vcore being low. I say that because I am surprised by how much your Vcore dropped under load, and to tell you that may be related to other settings that you and I use that are different.

Are you using a fixed, manual Vcore setting? I don't, I set it to Auto. If I did, I might get the drop in Vcore that you do, but I've never tested that. Right now, I am OC'd to 4.5GHz, with SpeedStep disabled, so it is constant, and my idle Vcore is ~1.256V. Vdroop really is unknown unless you use a set Vcore, which I don't, but I don't use full LLC, and I have good CPU cooling.

[parsec]

Re: Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

Auto for Vcore, Ok. It's difficult to continue with suggestions, since we don't even know what CPU you are using. You need to fill in your system specs, really a requirement for help in any forum.

[snowcake]

Re: Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

Auto for Vcore, Ok. It's difficult to continue with suggestions, since we don't even know what CPU you are using. You need to fill in your system specs, really a requirement for help in any forum.

(Temporary) Intel pentium g860 @stock (3ghz) Based on sandy bridge. With boxed cooler.
2x4gb =8gb 1333mhz kinston memory
Asrock H77M Motherboard. Bios v1.2
1TB HDD
Radeon HD4850

[parsec]

Re: Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

What I don't understand is how you could have as much change in Vcore under load with a non-Turbo, and non-overclockable CPU. Yes, the CPU voltage regulation is 4 + 2 phase, which is not very strong, but your current CPU does not need that much power.

Your fear of LLC damaging your CPU is not justified IMO, that is a common feature on any board, I've used it and never had a CPU damaged, or heard about anyone ruining a CPU from spikes from LLC.

What power supply are you using?

[cjapeterborough]

Re: Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

Sorry to jump in but can you confirm that the H77 chipset supports overclocking via the multiplier.
I believe it is not possible and only by base clock frequency (say 5% at best)
Hence LLC would not really be relevant for the OP -unless there was a requirement to undervolt perhaps?

The bios behaviour observed for LLC may be all to do with the H77 chipset...

[parsec]

Re: Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

cjapeterborough, good point, I was taking for granted the multiplier OC worked on this chipset, although not the original point or question the OP asked about.

You're right, the H77 does not support multiplier OC, although it has been claimed some boards allow it to an extent, but I wouldn't count on that.

But, I found something else when checking into the H77 chipset. That is, it does not allow Vcore voltage adjustment. It looks like a small offset voltage can be used, but that depends on the board.

How does this relate to LLC? Good question. Does LLC even apply with the H77, and a G860 CPU?

[painbot]

Re: Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

Interesting comments here .. but as far as i know no one hits the point ;)

What i read, is that LLC is a function to prevent Intel's VDroop resulting in more "stable" Vcore (less/no drop under load). It makes overclocking "easier" because you dont need to consider the Vdroop under Load when you set your VCore.
But VDroop is a necessary function, for further information check out this article: AnandTech - Overclocking Intel's New 45nm QX9650: The Rules Have Changed
What i also read, and makes sense to me, is that the conductance of silicium (as other materials too) is increasing with higher temperatures and under more electrical load .. that means, you can slightly decrease the power your shooting through your semiconductor to reach the same result ;)
In reverse it means, without VDroop, you would give your CPU too much energy it doesnt need cuz of the increased conductance under full load ;)

With my ASRock Z68M/USB3 .. i could choose between LLC Level 1 to 5
1 means LLC is fully working (100%) > it "corrects" Intels VDroop resulting in (almost) constant VCore
5 means LLC is disabled > Intel Vdroop specification is working resulting in Vcore drops under full load

With my ASRock Z77M, that setting has been changed to LLC 0%, 50% or 100%
0% = LLC Level 1 (constant VCore)
100% = LLC Level 5 (disabled)

I have LLC always disabled, cuz i dont want to damage my CPU (even if im overclocking ofc :D) and i have also lower temperatures without LLC ;)

[parsec]

Re: Load-Line Calibration (LLC) settings are reversed. 0% means 100%. Standard bios setting: auto....

Nice article, and although almost five years old and describing a CPU and chipset architecture that is no longer used, the Vcore, Vdroop, VID, and LLC concepts are basically the same today.

It's interesting how basic knowledge like this is not part of what is usually included in Intel CPU over-clocking tutorials. The main reason for that IMO is based on the generally accepted and deeply ingrained concept that what Intel tells us is true, versus what has been found to be true, are two different things. In other words, the rules set by Intel can be and are broken all the time, without any consequences. That is true in many cases, but not in all. The ability to get away with things has made users and mother board manufactures bolder in what they do, but there are limits and we have been more so lucky than smart.

For example, the memory speeds used with SB and IB CPUs are beyond the Intel specs, and openly marketed by board and memory manufactures.

Another example, over clocking via the Turbo multiplier is not meant to be constant, but time limited based on several conditions. Settings to break this rule are well known to board manufactures, and provided in the UEFI/BIOS as default settings. We can run our CPUs at 4.5GHz+, with memory operating at 2133 or beyond, and all is well as long as we cool the CPU enough.

I also don't see a droop in Vcore under load, apparently, but I use the CPU power saving options, so my Vcore is all over place, and not set to a specific value.

The explanation of Vdroop in the article makes sense, and the potential dangers of LLC clear. Or has VRM technology become fast enough to prevent voltage overshoot? Probably not...