Voltage wierdness with i9-9900K

[ValkyrieStar]

I was unable to OC successfully at all.. 5.0 is not stable even at and beyond 1.35-1.40v

 

So.. I though't i'd try undervolting it a little at its 4.7ghz turbo to see if i could do any better temps wise

I managed to get it down to 1.152v stable using offset voltage of -0.065v

 

But now i get the wierdness, at 4.7ghz with manual voltage, i cannot go below 1.232v before it crashes.

 

So why is the CPU stable at 1.152v with offset vCore, but that voltage instantly hard crashes when set manually, requiring being set to 1.232v to achieve stability with manual vCore?

[Kilrah]

Probably that manual is hard set and load line calibration is disabled, while it's doing its job in offset mode.

[ValkyrieStar]

35 minutes ago, Kilrah said:

Probably that manual is hard set and load line calibration is disabled, while it's doing its job in offset mode.

I have ASRock Z390 Phantom Gaming 9,

 

With all settings to automatic (LLC Level 4), voltage sits between 1.216-1.232v under load.

 

With manual voltage, i input 1.220v with LLC Level 1 (highest), which results in the voltage hovering around 1.216-1.232 at idle, and 1.232 solid during load.

I cannot drop the voltage at all below this, even 1.210v which results in 1.216 under load is not stable, crashing within 30s.

 

With offset voltage, i input -65mV with LLC Level 4 (auto), which results in load voltage of 1.168v, with occasional dips to 1.152v.

I can even lower this as far as -85mV, resulting in a load voltage of 1.136v, but that will eventually crash after some time, -75mV is stable as a rock though.

 

At least with this tuned -75mV undervolt, i am reaching 10c lower temps on the CPU, 81-82c vs ~92c