Load Line Calibration, is it really "auto-cheat" for CPU Overclocking tests?

[GundamF91]

As you know, there's a well known Anandtech article on the effects of Load Line Calibration (by Asus and other board makers). Anandtech article on 45nm QX9650

Basically the LLC is there to offset the vDroop that overclockers so despise, because it stands in the way of safe overclocking by requiring more vCore than VID would suggest. After reading that article, I've always had my LLC disabled. Since then, I haven't really been able to hit 3.6Ghz on my Yorkfield Q9450. It would boot to Windows, but it would not stabilize under load, and the vDroop would crash the stability tests until I raise vCore more than I am comfortable with, ie. 1.33v in BIOS vCore.

Today I decided to venture out and see how LLC would help overclocking. Right now I'm typing on this rock stable 3.6Ghz, with only 1.275v BIOS vCore, with LLC enabled and everything else stock. The best thing is that the actual vCore is 1.272v (in CPU-z). Interestingly, vCore idle is 1.264v, a few mV lower than the vCore load. This is best example of LLC in action, compensating for the heavier power draw. In a way, you can say LLC is an auto-cheat implemented by Asus and other board makers to help stabilize CPU when there's significant load, ie. the overclocking stability test when the CPUs hit 100%.

Still, I am not sure if LLC is a cure or a curse for overclockers. This is basically a pencil-mod implemented by the board makers (overwriting the Intel spec). LLC definitely seems to improve overclocking ability, at least by not requiring as much vCore, and it also compensates for power draw. On the other hand, based on Anandtech article, it could also potentially hurt the CPU as your system swings backs and forth from load to idle.

 

[Idontcare]

If you consider LLC as being an auto-cheat feature then you should probably consider anything and everything else in the BIOS that you tweak for overclocking to be a cheat feature. (ram dividers, FSB settings, Vcore, etc)

Real men don't need to BIOS adjust their FSB to overclock, they phase-shift the crystal generator for the board and hard-wire in their new base frequency :laugh:

Personally I loved the LLC feature on my Asus P5E Pro. It made the difference between being able to clock to 4GHz stable or not getting there at all.

 

[GundamF91]

Dont' get me wrong, I am definitely warming up to the LLC feature on my Asus P5Q Deluxe. It certainly helped me to hit 3.6Ghz with great ease. If I turn up my liquid cooling speeds, it should hit 3.8ghz or more. It's almost like an "overclocking feature", to automatically compensate for power demand. The only thing that still concerns me is Anandtech's article. It shows why LLC works, and also why LLC can be detrimental.

 

[VirtualLarry]

Does DFI implement LLC?

 

[Rubycon]

It's a form of compensated regulation. That has a political jingle to it!

 

[GundamF91]

Not sure if DFI has it. I do know for sure that some of the boards have it in there, to a lesser extent, even if they don't tell the users. I used to have Abit IP35-E, that board has vDroop as bad as my Asus P5Q Dx with LLC off. But by comparison, I have also used Abit IP35Pro, that board was great, had much smaller vDroop than IP35E. The Abit IP35 Pro is nearly as good on vDroop as Asus with LLC on, even though the Abit board does not have any BIOS choice in LLC or other type of adjustments.

So this tells me that the higher end board of the board makers would implement something to this effect to regulate power compensation, even if BIOS doesn't tell the user about it. This helps with stability and also makes the board look better when overclocked and tested.

 

[Idontcare]

Originally posted by: GundamF91
The only thing that still concerns me is Anandtech's article. It shows why LLC works, and also why LLC can be detrimental.

Emphasis on the "can" be. Any form of overclocking can be detrimental if done in foolish manner (extreme values or inadequate cooling of the relevant components).

Setting your Vcore to 1.8V w/o LLC is no less detrimental than setting it to 1.7V w/LLC (in either case your CPU is likely being exposed to 1.8V or higher during transitions to unloaded conditions).

So just don't abuse it and you'll be fine. You don't set your Vdimm to 2.8V do you I wouldn't be worried about the lifetime reduction your CPU is no doubt experiencing because of the voltage spikes during unload thanks to your use of LLC.

You are still going to replace that chip in 2 yrs regardless whether it has another 5yrs or 10yrs of functional life remaining. (as will I!)

 

[bharatwaja]

Originally posted by: Idontcare

Originally posted by: GundamF91
The only thing that still concerns me is Anandtech's article. It shows why LLC works, and also why LLC can be detrimental.

Setting your Vcore to 1.8V w/o LLC is no less detrimental than setting it to 1.7V w/LLC (in either case your CPU is likely being exposed to 1.8V or higher during transitions to unloaded conditions).

So just don't abuse it and you'll be fine.

Does this affect the CPU only at high temps like ~1.35 or so???
I have set vcore to 1.21 in BIOS... and I have LLC enabled.... if at all this affects me, wouldn't the effects be negligible or is the impact irrespective of voltage?

 

[Idontcare]

Originally posted by: bharatwaja

Originally posted by: Idontcare

Originally posted by: GundamF91
The only thing that still concerns me is Anandtech's article. It shows why LLC works, and also why LLC can be detrimental.

Setting your Vcore to 1.8V w/o LLC is no less detrimental than setting it to 1.7V w/LLC (in either case your CPU is likely being exposed to 1.8V or higher during transitions to unloaded conditions).

So just don't abuse it and you'll be fine.

Does this affect the CPU only at high temps like ~1.35 or so???
I have set vcore to 1.21 in BIOS... and I have LLC enabled.... if at all this affects me, wouldn't the effects be negligible or is the impact irrespective of voltage?

The effect will be negligible for you in your case.