Question Overclock I7 6700K Problem

[Robox]

I tried to overclock a liquid-cooled I7 6700K on an MSI Z170A Krait gaming X3, updated to the latest bios, making these attempts in the settings:

OC Explore Mode: expert mode
CPU Ratio Apply Mode: all core
CPU Ratio: 46
CPU Ratio mode: Dynamic Mode / Fixed Mode
Ring Ratio: Auto
EIST: Enabled / Disabled
Intel Turbo Boost: Enabled / Disabled
CPU Core Voltage: 1.35v / 1.40v
I also tried disabling these features: Intel Adaptive Thermal Monitor and Intel C-State

I tried with Linx, prime 95 and IBT and with all the behavior is always the same: after a couple of minutes the multiplier goes down to 44 and the frequency to 4400MHz, continuing the test at this fixed frequency.
Temperatures are always good.

Do you know if it is normal or is there something that causes this abnormal behavior?

 

[appletatoes]

I have the same CPU and you can't really go any higher than 4.5GHz. Are you having a problem where you set it to 4.4GHz and then it drops down to 4.0GHz?

 

[Robox]

I have set all the limits to the maximum, from the "cpu Futures" section and now it is more stable, but anyway at a certain point I have continuous drops in the multiplier (the frequency does not go down to 4200 fixed, but goes up and down continuously).
I have been monitoring with hwinfo and am getting these warnings in conjunction with frequency drops: IA: VR Thermal Alert and RING: VR Thermal Alert on Yes.

I guess it's the temperature of the motherboard vrm or something integrated into the processor.

So I have some questions about it:

1) what is it exactly? (is this the cause?)

2) Besides lowering the vcore and trying to place a fan on the motherboard heatsinks on the VRMs, is there any other setting I can try in the bios settings (like lowering some other frequency or voltage besides the vcore)?


(The case is a big tower with two 140 inlet fans, one 120 in extraction on the back and 3 120 in extraction on the radiator on the top of the case.)