Any Z370 Pro4 owners here?

[telepman]

Hi,

I'd appreciate some advice. I have a locked CPU so I feel kinda bad asking this on Overclockers, but the people here are the best.
I'm trying to undervolt my new i7-8700, so far set the Vcore to -75mV offset and I get 1.28V max, with temps going over 70C with Prime (2nd round of blend test) and HEVC encoding, while all cores are at 4.4GHz (bclk is 102,3 by default). I read people run 8700K at 5GHz with that voltage, and I'm not happy with the temps, so should I just lower the Vcore further or should I play with LLC? I used LLC before with overclocking, but this is different now, there's turbo and I don't know what levels 1 to 4 mean (as in which is the most aggressive setting). What's the lowest stable voltage for most 8700's?

 

[EarthDog]

Lower the Vcore further. LLC is there to simply prevent sag when under load. Sometimes it raises, but that is normally if it is set too high. It doesn't do that on auto, typically. I do not own the board however if the BIOS doesn't tell you which way it goes, you can always test it out and see. Set it on 1, check voltages under load... Set it on 4, check voltages under load.

As far as lowest stable voltage... it will vary by CPU. No idea... that is part of the game my friend.

 

[telepman]

Alright, let's see how low I can set it.

 

[mackerel]

I have that mobo and working out voltages is a pain. The core voltage reported in Asrock's own utility seems to correlate with the bios, and recent versions of hwinfo64 also seems to report the same. When on auto, it does seem erratic and setting a fixed manual voltage is on my to do list.

 

[telepman]

OK so at -150mV it wouldn't boot and at -125mV it's not stable. Friend keeps 8700K at 4.3 with 1.168V, a lot lower then what I got. I guess I'll need to disable some of the green features.

 

[mackerel]

Be careful when using negative offsets as it applies to low power state as well as full load. It is more likely to be falling over at low load since the voltage drops unless you turn off power saving. Alternatively use a fixed voltage.

 

[wingman99]

Does ASRock have IA AC/DC calibration so negative offset is not needed? I know Gigabyte and ASUS has that option.

 

[telepman]

I didn't see that option, and I don't know what it is TBH. Anyway my new GPU finally arrived a few days ago (I'd been using IGP), so I was focused on PUBG hehe. The temps reach 65C max which I guess is not bad, but I'll try applying fixed voltage just to find the lowest stable setting. I don't like the idea of having constant voltage tho.

 

[wingman99]

IA AC/DC calibration allows me to set the offset Vcore from negative value that can cause stability issues when off turbo boost speeds and when running idle to a positive offset with keeping the those values above stock.