R5E10 Adaptive VCore problem

[EAC]

I’m having problems with adaptive VCore, in that when my i7-6950X is overclocked to 4.0GHz, the voltage at load is always 1.28v, any value below this entered in “Additional Turbo Mode CPU Core Voltage” is ignored.

I have the same issue on both the Rampage V Edition 10 (BIOS 0502 & 0601) and Sabertooth X99 (3101).

My previous i7-5960X works as expected on both boards (voltages down to the stock VID are accepted when using adaptive).

When the 6950X is used with an ASRock X99M Extreme4, adaptive voltage works as expected, for example setting adaptive 1.18v results in ~1.183v under load.

I’m fairly experienced with using/overclocking Asus motherboards, but am I missing something obvious?

Thanks.

EAC.

[erixx11]

But does the CPU speed slow down by Windows Power Plan or stays always at 4 Ghz?

[EAC]

Hi, yes I'm using the standard "balanced" power plan, and the CPU drops to 1.2GHz at ~0.875v at idle.

If I drop the turbo speed to 3.8GHz, the hard limit becomes 1.23v, adaptive settings below this are ignored.

[Raja]

As you are experienced, you should be capable of following the advice below:

You can't set the adaptive voltage lower than the non-Turbo ratio VID. That's why it's labeled as an additional voltage target. The additive being a VID that is greater than the offset VID stack. When the CPU is under sufficient load, VID is scaled through the offset VID stack up to the adaptive voltage target.

To work with this, what you can do is apply a negative offset to the adaptive voltage. However, you will need to evaluate stability coming out of idle, as an offset will be applied to the entire offset VID stack. This can cause issues coming out of idle or for loads applied to non-Turbo ratios as the VID can be too low.

The other option you can try is the ASUS Thermal control tool's VID override function to enforce a manual target voltage at a given temperature - you can still use adaptive in UEFI so you get power saving outside the upper temp target freq.


-Raja

[EAC]

Thanks Raja, Yes, I'm aware of the basics of how VID works and scales, just confused as the non-turbo VID is ~1.00v, similar to my 5960X. For that I can use adaptive 1.10v for example, but for the 6950X I can't use anything below 1.28v. I can't really use an offset, as I determined (using manual voltage) at 4GHz I only need ~1.17v for stability.

I have no trouble using an adaptive of ~1.15 to 1.18v on an ASRock board. I know you can't speak for how that board is set up, but I would have thought adaptive voltage would be more or less the same on all X99 boards?

Beyond that, I will take a look at the thermal control tool.

Thanks,

EAC.

[Raja]

EAC wrote:
Thanks Raja, Yes, I'm aware of the basics of how VID works and scales, just confused as the non-turbo VID is ~1.00v, similar to my 5960X. For that I can use adaptive 1.10v for example, but for the 6950X I can't use anything below 1.28v. I can't really use an offset, as I determined (using manual voltage) at 4GHz I only need ~1.17v for stability.

This is where your misunderstanding lies. The default non-Turbo VID changes with the applied core ratio. It is not 1.00V for every ratio. As it scales, so does the minimum adaptive voltage you can set. You can set the offset to something other than Auto, and then work with the scale.

Just to reiterate, read the first two sentences of this post again, this time, think about how Intel's Turbo would work even at stock if offset voltage didn't scale according to the active ratio. The default offset voltage has to change with the applied ratio, if it didn't, the load VID would be static, which would negate power savings and the whole concept of TDP dependant frequency.

Thermal control tool: http://edgeup.asus.com/2016/05/31/get-best-performance-broadwell-e-processors-asus-thermal-control-t...

[xarot]

Just out of curiosity, which monitoring tool are you using to check voltage under load? I am just trying to find hints to my own Vcore voltage issues with BW-E.

[EAC]

Thanks again Raja, yes my mistake, I was getting a little confused there, and perhaps I should have re-read what I'd written a couple of times before posting. I did try using a negative offset with adaptive, but reducing the VID stack by more than 0.1v is quite a lot, so I was concerned with creating instability at lower clock speeds. I will do more testing, I guess the 6950X I have is just a bit greedy for voltage!

Thanks for the link to the thermal control tool; I will give that a try.

Cheers,

EAC.

[FireRx]

Thanks, Raja!
you answered my question too while I was trying to tweak my voltages. that explains why it was trying to compensate for my attempted lower voltage and offsets. I'll leave well enough alone.. 🙂