Originally Posted by elmor
I'm not sure which "+100mv" rumor you're talking about.
This quote shows the result of the improved readings, where it looks like lower voltage on M11 but it's really other boards that read too high.
IA AC/DC loadline are load-line values that are applied to Intel SVID requests, and thus only affects Adaptive/Offset voltage modes. They are tuned per board, the 1.6mOhm recommendation from Intel means that the board design should result in a value lower than this.
If a CPU runs at a certain frequency with a certain load, it has a table specifying the required voltage for that scenario (VID). Let's say the CPU frequency is 4.7 GHz, the output current 100A and the required VID is 1.300V. The IA DC load-line value has been set to 1.0 mOhm. Using this IA DC load-line value, the CPU will compensate for board losses and VRM load-line by applying an offset to the requested VID. The theoretical voltage drop will be load-line*output = 1.0 mOhm * 100A = 100mV. Probably then the CPU will request something like 1.300+0.1 = 1.400V. Then there's also the Load-line Calibration BIOS option which changes the VRM load-line value and probably also the IA AC/DC load-line Auto values. The different "levels" are fixed sets of tuned load-line mOhm values. AC load-line values are for transients and add even further complexity.
The VID value is what the CPU requests, not what it gets. Your actual CPU Voltage will be slightly lower than the MLCC reading. Does HWInfo pick up the VRM controller (IR35201) as a separate sensor on your board? That should provide a very accurate voltage.
Learned a lot today from you, Elmor. Probably more than i've learned all year. Thank you. I was always wondering how that formula worked.
(At least I always tell people NEVER to go near the higher values for the IA AC DC loadlines).
Anyway this 100mv rumor has been spread all over. And your chart basically puts it all to rest completely with proof.
Here's the threads.
There was also a thread on a German or i dont know some strange european language with de (?) site and a chinese site too.
There was something brought up here about that too, but referencing those.
Yes HWInfo picks up IR35201 as a separate sensor.
The idle vcore voltage shown on the more accurate vcore sensor--there are two, the (ITE IT8792E) is more accurate than IT 8688E), is equal to the "VR Out" (IR 35201) voltage at idle.
At full load (I am using LLC=turbo), the ITE IT8792E sensor is about the same as idle, while VR Out drops a whole lot.
Right now when writing this, I have vcore set to 1.270 in the bios.
Idle shows up as 1.265v for the ITE vcore sensor and "VR VOUT".
Full prime95 load (No AVX) shows 1.276v for the ITE ITE8792E Vcore sensor and 1.230v for VR Vout (IR 35201).
Are you saying 1.230v is the true voltage the CPU is getting?
I thought VR Vout was the vcore that "would" be the voltage if I had loadline calibration disabled...