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.

[PancheZ]

Hello!
I have a 13600K and a TUF B660M PLUS D4, but the system is unstable. What did I do wrong?

[rchrds]

-0.125v is a pretty big offset to start with. I haven't done much testing but the cache voltage tends to be less stable and I would also set Load Line Calibration to 4 or 5.

[PancheZ]

I have achieved at least some stability and some sane temperatures at offset -0.15 and LLC 1
But I am confused by the average temperature of 1.3 volts in the load.

[wcs531]

It looks like they've released a new BIOS with generic release notes (copied below), but I'm hesitant to try it considering the microcode workaround with 13th gen.  Maybe some 12th gen CPU users want to test it out since it seems they don't have access to the alternative microcode anyway?

ROG STRIX B660-I GAMING WIFI BIOS 2403

Version 2403

11.03 MB 2023/04/20

"1. Optimize BIOS & Intel ME update mechanism.
2. Improve system stability"

[RastaManMax]

I just ran the update on the B760i and doesn't seem like it changed the ability to undervolt on my i7 12700k unfortunately. 

[Primordiarch]

I have B760I-Strix paired with 13700KF. CB23 Scored 29k-ish stock and if I offset it, It could reduce to sub 20k.

I really wish I could undervolt it. Right now it always pull 253W power everytime I run CB23.