B660-I: Performance drop with voltage offset/undervolting

[Shosiu]

Hi,
This issue has been initially described in another thread but I decided to start a separate one.
I noticed on my B660-I Gaming, that any negative voltage offset causes noticeable negative performance impact.
As the example - results of Cinebench R23 (multithreaded)
stock settings: 12700 points
0.05 voltage offset: 12200 points
0.08 voltage offset: 7100 points.

This issue is not present on other Asus B660 motherboards - it's working properly on B660M Plus.
It doesn't matter if APE is enabled or not - CPU performance is affected.

My CPU is i5 12500.

It would be good, if someone from Asus tech team compares the behavior of those two motherbaords and make a fix for B660-I as currently undervolting on this motherboard doesn't work at all.

Thanks.

[trihy]

Here you have

First result stock voltage

Second 0.120v undervolt

Third 0.050v undervolt

[Shosiu]

Are you using any special settings in bios or it's just stock, with VRM Core Voltage Offset?
What's the power consumption after undervolting?

I'm asking as few posts earlier we have info from Asus, that using voltage offset they got the same results on B660-I and B660M Plus.
I try to understand, what you additionally did to keep the performance, but just lower the voltage and power consumption.

Thanks

[trihy]

Hi. Never see any performance loss.

Just changed actual vrm core voltage offset and ram voltage. Every other setting is on default or auto.

Power consumption goes down from around 70w to around 60w. Not much but better temps too.

Load vcore voltage running cinebench23 multicore is around 0.980v.

Instead of offset, try a fixed vcore to see how it goes. Just set actual vrm core voltage to manual and put something around 1.080v and run some benchmarks.

[Shosiu]

I have just checked with manual voltage of 1.07V and my result in Cinebench R23 was almost 5400 points (doesn't matter if APE was disabled or not, in both cases result was the same). What I noticed is that Power Draw dropped from 82W to 55W.
I was even playing with AC Load Line but still the same result: heavily impacted performance.
Question to Asus support: how is that possible, that user "trihy" doesn't have any issues with undervolting on his motheboard (B660M Plus) but I have with B660-I?
We had another user in another thread saying, that undervolting was working properly on B660-G Gaming.
How you can't see the issue if I provided two times the proof, that ANY undervolting, even the smallest one, is causing performance drop?
Can you then provide a way, how to undervolt to keep stock performance, but lower wattage? How can I do that on this montherboard?

[STARRAIN]

Hi Shosiu,
Sorry we cannot guarantee the undervolting or overclocking performance or results, and we don't know the best parameters for your components.

[Shosiu]

STARRAIN@ROG wrote:
Hi Shosiu,
Sorry we cannot guarantee the undervolting or overclocking performance or results, and we don't know the best parameters for your components.

I'm fully aware that you can't provide me the exact settings to undervolt.
But my main question remains: how user "trihy" can undervolt keeping stock performance with lower voltage/wattage while I can't?
What's the difference between B660M Plus and B660-I, or B660-G and B660-I? For both - B660M Plus and B660-G - users reported that undervolting works properly.
Why people are complaining about B660-I only regarding undervolting in different threads on the internet?

[Zinthar]

STARRAIN@ROG wrote:
Hi Shosiu,
Sorry we cannot guarantee the undervolting or overclocking performance or results, and we don't know the best parameters for your components.

I think there's been a misunderstanding here. Shosiu was not asking for a guarantee of performance.

Slightly undervolting Alder Lake/Raptor Lake in small form factor PC builds is a very common use case for ITX motherboards, and I think it's a fair question to ask if the Asus B660-I is capable, in any currently available BIOS, of setting even a very slight undervolt while maintaining the expected performance of the CPU. A slight undervolt can often increase performance for certain workloads because it provides additional thermal and power limit headroom for the CPU.

Which setting(s) should users of the B660-I adjust to effect a small undervolt of the CPU without performance loss?

Upon re-reading your earlier comment, it sounds as though the tech team may have just tested the board with vcore at auto, which would not necessarily reveal a bug in the BIOS that disables turbo if an offset is selected.

I don't own this board, but am planning on buying an ITX for Raptor Lake, and being able to undervolt it is a must, so I'm very curious if that's possible.

[trihy]

Not sure if this could help

https://www.techpowerup.com/forums/threads/i7-12700f-b660-terrible-performance-under-manual-voltage....

"I found out. You need to set Core voltage to ADAPTIVE , not MANUAL. Or else you loose boost.
But this should be fixed with new BIOS."

Not sure about that. Still adaptive is not available for b660 boards

[STARRAIN]

Hi Shosiu and Zinthar,
As mentioned our tech team tested ROG STRIX B660-I GAMING WIFI and TUF GAMING B660M-PLUS WIFI motherboards and the results are the same. The more voltage offset(undervolting), the more performance loss.
Different components or other settings adjustment probably also affect the performance, so we cannot guarantee the undervolting or overclocking performance or results,
Thank you.

[Zinthar]

STARRAIN@ROG wrote:
Hi Shosiu and Zinthar,
As mentioned our tech team tested ROG STRIX B660-I GAMING WIFI and TUF GAMING B660M-PLUS WIFI motherboards and the results are the same. The more voltage offset(undervolting), the more performance loss.
Different components or other settings adjustment probably also affect the performance, so we cannot guarantee the undervolting or overclocking performance or results,
Thank you.

This answer does not inspire confidence in the B660-I. That's not normal behavior for this Intel chipset and the tech team should really consider whether this is actually a bug in the BIOS, as it's almost certainly not a hardware limitation of the board.

If vcore is reduced sufficiently, the system should become unstable and crash rather than drop performance. Experienced builders are capable of determining the capabilities of their components if the BIOS functions as it should.