(big pinch of salt but:) my 13900K may be more stable re tunability since x1209 microcode update

[Gurgeh]

Take the following with a massive pinch of salt but my 13900K may be more stable in terms of its tunabilty since the x1209 microcode update.

Not withstanding problems with XPMII profile stability which recently vanished when I revisited again applying BIOS defaults, I have been able to improve my global adaptive undervolt from -0.052V to -0.100V stress tested. (although, from here on I'm running with a margin at -0.090V)
Big pinch of salt though.
-Its been a long time since I did my first undervolt, maybe my methodology has changed (this could be good or bad either way, ought to be for the better though.)
-I'm certainly no longer using AVX guardband scale factor of 100. This could be a reflectionof stability improvements, or it could be an example of my original approach that was flawed.

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From my very loose understanding (its largely immaterial to what I want to do with my CPU) the x1209 has corrected some 'unexpected' requesting of too high a voltages. So it might make sense that there is less 'effective' overshooting, and therefore less exposure to VDroop the other side of that? again just thinking out loud. When it comes to this level of detail I'm at best ammateur. (I get what I need from transferred engineering practices regarding  general modelling, testing, and risk mitigation, and basic linear electronics)
..oh also heat. less heat, easier conditions for stability.

I understood burn-in was a process intended only to reveal silicon that has come from factory as a lemon. But perhaps burn in can improve a chips stability? (if anyone wants to try and corroborate this please do, although before I'm convinced I'm going to need siting of linked material from either intel.com or amd.com. I'm just thinking out load.)

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Has anyone else got better stability as of the microcode change? (because my sample of one is as likely to see the difference being me rather than the microcode. At eh very least a bit of both.)

[achugh]

Hi @Gurgeh i believe you are talking about 0x129 Microcode but in your post title and your message you currently have it written as x1209. I recommend that you edit your title and post message so that search results can find your information.

Now, my understanding is that older versions of BIOS (and I am not sure which version you had before installing this most recent version since you have not mentioned) were using lover CPU Load Line Levels. A lower load line level  (below 4) means increased Vdroop. This means your CPU is getting much less voltage than requested which leaves less headroom for further undervolt. At the end of the day, your CPU can only take so much undervoltage which if your CPU has not degraded would have stayed the same between older BIOS and newer BIOS.

The newer BIOS now defaults to higher CPU Load Line Level values (above 4) hence the requested CPU voltage and the voltage given to the CPU actually will be a close match. This gives you the illusion that you can now undervolt a bit more while that is not happening. This is because if your CPU has not degraded it can only take so much undervolt as I have explained above.

The voltage your CPU will get is following the following very simple formula for high level understanding. NOTE - this information below has some gaps and is not the complete picture but for high level understanding it is sufficient.

CPU Requested Voltage - CPU Load Line Level factor reduction - Global Adaptive Undervolt = The voltage CPU will get.

See https://www.youtube.com/watch?v=9slwXKUwmnE video to understand these CPU Load Lines and what they are doing to CPU Voltages. If interested to learn further, also see https://www.youtube.com/watch?v=XI2x2_skwSs to understand how to tweak your board for better performance.

I hope this information will help you understand what is going on.

[Gurgeh]

Hi Achugh,
Very sharp! And the loadline level would be a very likely candidate, except... I was 'very' particular in 'selecting' Level 4 for my original configuration about a year ago (given the intel issue, that was not all in my favour though 😕 . I wonder if ASUS picked 3 it because they saw something odd happening). I noticed immediately that had now changed. I even reset again to check 4 was now the default. that It was one of the few original changes I made. (saving applying my own Tmax and reducing the PL1 and PL2 and max current because they were always stupid. That said I've reduced them further as drilling into excursions beyond those limits they are kind of scary.)

Thanks though Achugh. Excellent suggestion!

[achugh]

Hi @Gurgeh I am not sure how good or credible this following video information is but it is definitely something to consider.

https://www.youtube.com/watch?v=afN6SaT21cQ

In this video, this YouTuber is working with what is considered a degraded CPU and he states that the ASUS CPU SP value is based on the V/F Frequency Curve. This is why when this particular CPU degraded the SP value did not change. He also mentions that a memory of his community on discord sent this CPU to him so I don't understand how he would know the original SP value.

The reason I am sharing this link here is that you really do not need to set values that under perform if you have a properly working CPU. As long as you have the lates 0x129 Microcode and are following Intel recommendations things should begin to get better for everyone. I am referring to the following comment above.

I wonder if ASUS picked 3 it because they saw something odd happening). I noticed immediately that had now changed. I even reset again to check 4 was now the default. that It was one of the few original changes I made. (saving applying my own Tmax and reducing the PL1 and PL2 and max current because they were always stupid. That said I've reduced them further as drilling into excursions beyond those limits they are kind of scary.)

Basically, what ASUS will pick as a default is somewhat connected to this predicted SP value and when CPUs degrade and if this value truly does not change, it makes sense to me as to why people will have issues.

Regarding PL and Tjmaxx I would not set them lower than what matches your particular CPU at this time. There is no need for it since a lot of useful and good information is now available to finally make sense what is happening; at least to me.