Unstoppable

Hey dudes,

Yesterday I flashed my Asus P6T-Deluxe V2 to bios version 0406.
That bios unlocked the 21x multiplier in BIOS for me, and my chip seems to like it much better than the 19x and 20x multiplier.

However, to get a stable overclock @ 3,8Ghz (21x181) I need to use 1,3625V with LLC enabled. Whenever I disable it and try to stresstest, it freezes in about 2 seconds.

I've heard that some people recommend LLC enabled and some people say that it will kill your CPU. So my question is, is it safe to enable LLC at 1,3625V or higher? Or should I wait for a pencilmod for my mobo?

And last question: What is the max voltage I should use for my Core i7?

TwoCables

Well, the VID Voltage Range is .80V-1.375V, so I'm assuming that the maximum safe voltage for every-day type of use is 1.375V.

What does CPU-Z say that the voltage is during a cpu-only stress test (with LLC enabled)?

__________________

scottath

Generally - the loadline calibration works as it should - to reduce vdroop - so use it

Voltage wise - within the VID range is "warranted" for it to run at stock speeds
The VID of your chip is what intel has said your chip will run stock at (usally wrong though...my Q6600 1.3125vid can run at 3.2ghz (2.4 stock) at 1.28v - under the VID...)

__________________

My Mod in Progress |||| 3DMARK06 PB: 22044

TwoCables

Not only can LLC reduce vDroop, but it can eliminate it. But it can also reverse it too, which is called "vRise". vRise is what introduces the possibility for killing the CPU because some people aren't careful and don't know how to experiment with something new. They're the kind of people who had their vCore already too high and had a motherboard with an LLC that caused vRise, thereby making the vCore even higher than "too high".

In other words, as long as you're intelligently careful, there is absolutely nothing to worry about.

__________________

Acoma_Andy

Personally I keep LLC disabled to stick to Intel specs, I don't mind the vdroop.

__________________

Unstoppable

I currently have it running on 3,2GHz with 1,1685V (set in BIOS). With LLC enabled.
Idle the voltage in CPU-z shows 1,160V.
Under load it's at 1,168V.

So I guess we can speak of vRise here.
But the vCore given under load is the same as the value set in BIOS.
So I guess that is good?

TwoCables

From the little bit that I know, that's very good. I wish I had zero vdrop in addition to my zero vdroop. Or, I guess I should say that I wish I had vRise. lol

__________________

Blameless

Intel's specs are written with their default implementation of voffset and vdroop (which is 100% intentional) in mind.

LLC will give a significantly higher voltage than this.

Still, i7s are, in my experience, quite durable with regards to voltage, and ~1.38v LLC on likely does not present a significant threat to the CPU.

Unstoppable

Thanks for all your help so far!

@TwoCables: Yeah, I think I can say that on my motherboard LLC works close to ideal ^^
But I guess how well LLC works is different from motherboard to motherboard then..?

@Blameless: So according to what you are saying;
If I set my voltage at 1,3750V in BIOS with LLC enabled, it will go even higher (like 1,38V) even though CPU-z says it isn't?

But my answer to my question is:
LLC is safe to set to enabled as long as I keep checking if my voltage is safe under load. Right?

Blameless

Intermittently and esp when you leave high loads, voltage will spike, probably quite a bit. These spikes will likely be too short in duration for the monitoring hardware on your board (and hence CPU-Z) to pick them up.

vdroop and voffset exist so the peaks of these spikes do not exceed the VID you have set in the BIOS.

LLC disables or even inverts these features, removing the protection from these spikes.

Again, you can't tell what the peak voltages will be (not without a very good multimeter or an oscilloscope), but since the absolute max rating on the i7s is 1.55v (a full tenth of a volt higher than the 45nm core 2s) as long as your load voltage is not exceeding 1.4v or so, I highly doubt your chip will die (because of voltage) before you get several years out of it.