Intel 9700k ignoring vcore limits

Osmium · December 18, 2018

Hey guys, longtime member here but I've been inactive for a year or two.

I've been having some strange issues with my system in regards to high temps, seemingly caused by the CPU simply not respecting the vcore which I set in the BIOS.

My motherboard is THIS one, although I believe all gigabyte aorus z390 boards will have a functionally identical BIOS. All the following data is observed from HWMonintor. My CPU Cooler is the 280mm CLC AIO from EVGA. My case is an Enthoo Evolv ITX with 5 140mm noctua fans, so airflow isn't a problem. Also, I've tried setting different power profiles in windows before anyone suggests this. Power supply is also a 650w 80+Gold PSU from EVGA.

Running the latest BIOS, and all default settings(everything set to auto, except multicore enhancement disabled), my CPU runs at max 2 core boost (4.8GHz) idling at the desktop, and voltage fluctuates around 1.35 with wild fluctuations ranging from 1.1 volts to 1.4 volts.

Then, if I manually set vcore to 1.28 and disable adaptive voltage switching, the voltage at the desktop will fluctuate between 1.1 and 1.35 volts averaging around 1.15.

Now, if I run a program like the latest version of prime95(the avx intensive one), then my voltage will initially start around 1.28 where I want it, but it will gradually creep upwards until it reaches around 1.33-1.5V over a timespan of approximately 2-5 minutes. Running OCCT does the same thing.

Tweaking Loadline calibration doesn't have an effect on this upward creeping of voltages, in fact it causes it to end up at a higher average voltage(inline with what I would expect with a higher vcore setting).

All of this suggests that something is telling the CPU to overvolt, like a fixed overvoltage offset, and something is telling it to turbo. However, all settings that I can think of in the BIOS I've tried manually setting to off or their minimum respective value.

Does anyone have any insight to the situation? All I want, is for me to set a max vcore and for my system to not push it more than .1 volts above whatever I set.