@Ariuc Looks like you've done your homework.
I just want to make sure that other users who are not using higher tier hardware like you are, and who are not well versed on what loadline calibration actually does, don't just rush into pushing the 0 mOhms Loadline calibration (LLC level 8, Ultra Extreme, etc) into their CPU's and think "wow this is the best thing ever, why don't they all come like this?"
Raja, one of the engineers at Asus (when their forums still allowed private messages) taught me what the AC and DC loadlines (not to be confused with Loadline calibration, or LLC (also known as VRM loadline or just "Vcore Loadline Calibrationi)) did on auto/offset voltages, and he also explained the dangers of removing too much vdroop. Asus and other ODM's allowed such high levels of vdroop removal because "people kept begging them for it", so they gave the community what they wanted, even though they knew most end users had no idea how loadlines actually work (who here on this thread understood that Loadline Calibration is in mOhms (the same resistance value as the AC and DC loadlines?) and what the actual "levels" really meant? See?
For Gigabyte Z390 boards using 8 core processors, here are the resistance values for each level of Loadline Calibration:
Standard / Auto / Normal: 1.6 mOhms
Low: 1.3 mOhms
Medium: 1.0 mOhms
High: 0.8 mOhms
Turbo: 0.4 mOhms
Extreme: 0.2 mOhms
Ultra Extreme: 0.01 mOhms.
Vdroop = Amps * Resistance. Gigabyte boards have amps monitoring via the IR 35201 voltage controller (or the Intersil controllers) in HWINFO64 (Asus does not, sadly, even the eVGA Z390 dark doesn't seem to), so if you see your amps in IR 35201, multiply that by your LLC resistance, and then subtract that from your bios set voltage in millivolts. Example:
1.30v=1300mv, turbo LLC=0.4 mOhms. 100 amps load: 0.4 * 100 = 40. 40mv drop. 1300-40=1260mv=1.260v. Your VR VOUT should read 1.260v. That's your load voltage with 100 amps. Ignore the ITE 8688E sensor (Super I/O chip) and 8792E sensor (more accurate but won't show accurate vdroop).
It's also not Asus or Gigabyte's or other ODM's fault that transient spikes and drops happen. Asus doesn't make the VRM's. The companies like DrMos, Osemi(?), International Rectifier, Renesas (Intersil), etc, make them. You have the voltage controller itself and then the actual power mosfets. But these VRM's are not spec'd to run with a 0 mOhm loadline at all. Even the official datasheets show the loadline information and none have a 0 mOhm loadline as part of the specifications. So that's something worth noting.
I assume since you're a gamer, you probably have discord. You can add me if you wish with the tag at the of my exact same username: #6092
One way you can test for transient spikes is to use the hardest stress test possible, in this case, Prime95 with FMA3 or AVX (I like testing 15K in place fixed AVX or 21K or 22K fixed, or even FMA3), and find the VMIN first, which takes a lot of work (basically, to save time, the absolute minimum voltage you can set in bios, *WITH* LLC5 or LLC6 vdroop), to not crash a prime thread at load in 15 minutes.
https://mersenneforum.org/showthread.php?t=24094
This version of prime95 allows you to enable or disable AVX and FMA3 right in the stress test without editing TXT files (recommend anyone who enjoys torturing their CPU's grab it), but yeah, for exammple, do a prime test with FMA3 enabled, 15K fixed in place FFT (custom, min and max range 15K), with let's say, 1.30v and LLC6 and start there. If you INSTANTLY reach 100C and BSOD, disable AVX2 (FMA3) and just do AVX instead. If you pass 15 minutes, reduce voltage 10mv, reboot and try again until it crashes. Then record the **LOAD** VOLTAGE (not bios voltage!) that it took to pass. Your motherboard has a good bios which reads CPU voltage properly at load, as does Gigabyte Z390 boards (VR VOUT sensor in HWinfo, for anyone reading this!) and some MSI boards have VR VOUT. For non Asus WS / Maximus Z390 boards, if you have VR VOUT access in HWInfo64, use that for load voltage, guys.
Anyway record this voltage. So in your case if you set 1.30v in bios, LLC6, it might be 1.225v at full load on your Asus WS. If that's your stable prime 15K AVX FFT (29.8 builid 3) test, now switch to Ultra Extreme.
And set your bios voltage to 1.230v. LLC8 or Gigabyte Ultra Extreme. Yes, 1.230v. Because that was your load voltage remember? (usually controllers go in 5mv steps so im giving a cushion for accuracy).
Then run LLC8 + 1.230v. Do prime95 AVX 15K in place fixed FFT (custom).--min and max range 15K.
Your system won't last long. (If 1.230v were your actual load VMIN). You will either BSOD or a thread will crash in the first 5 minutes. That's because of transient drops. Even though it looks like Prime95 is putting a constant full even load on your CPU, the load actually changes very often, too fast to register, thus transient drop=crash.
Feel free to message me on discord (remember, my username with #6092 at the end, Falkentyne) if you want to mess with this XD
And now that I derailed this thread talking about VRM's....back to your standard programming!