Overclocking i7-8700K numbers

[Cheesy86]

Hello my awesome people. Back at it again. Just trying to learn as much as I can here from the fountain of knowledge that you all provide. Currently trying to OC my 8700k to 4.8 GHZ and make my way up. I wanted to see what you guys opinions are on temps, voltage, VCCIO and VCCSA. I ran a test last night on RealBench for 1 hr with the following specs and it passed:

OC: 4.8 GHZ

Package Temps: 73° C

VCore: 1.26

VCCIO: 1.1

VCCSA: 1.1

Also ran a test on Cinebench and went from 1301 (stock) to 1559. That's an 83% increase, pretty happy. The system is getting cooled by the Corsair H100i V2.

What do you guys think? I would like to try and stick around these numbers, maybe lower temps a bit if possible w/o delidding and I am open to any recommendations and thoughts you all have.

[Cheesy86]

I think I am going to stick with 4.9ghz Nate. I know I can get it in manual mode to stick at 1.30V and for what I'm going to be doing I'm ok with it. How do you recommend I proceed from here to try and get adaptive mode to work.

[Nate152]

Just switch to adaptive mode and enter 1.30v in the Additional Turbo Mode CPU Core Voltage Override.

Try LLC level 5.

You may need to use the offset in adaptive mode, you want the Maximum Vcore to read 1.30v - 1.316v max.

There's no getting around a little fluctuation and 0.016v is the smallest increments it fluctuates. I use manual mode myself, I set 1.440v with LLC level 6, it fluctuates between 1.440v -1.456v.

[Cheesy86]

Hey NATE,

Cool man. i will give that a go. Thank you so much for being so helpful and instilling this knowledge upon the community. Going to start messing with my rig and star doing some 3D work man. Thank you once again.

[Cheesy86]

How do you get that overlay of your specs and reading on your screen?

[Nate152]

It's with MSI Afterburner, the new GPU Tweak II has On Screen Display too.
There is a guide at the bottom of my post "On Screen Display" just click it.

[Cheesy86]

Nice man, going to set it up with my EVGA.

Would like your opinion on another things Nate. So, I think I have a solid stable OC for my 8700K at 4.8GHZ. I am currently running 1.295V on manual mode for 4.8GHZ. I was originally running it at 1.27 and I managed to pass Realbench, Aida64, Intel burn test and Cinebench just fine. But when I would check stability for OCCT it would FAIL after 15 mins. After changing voltage to 1.295 I got through 3 hours of OCCT. I was currently trying to go for 4.9GHZ but I am already at 1.34V and once again I have the same issue. Passing all tests except OCCT. Temps are still in the high 70's with a few spikes to 82 degrees. Is this normal behavior that I can get through these stress tests but not OCCT. Whats the average voltage, in your opinion, for adequate OC of 4.9GHZ?

[kalle-m]

The things happening to you, might not be your cpu failing!!!

I don't want to bash on you or anything, so don't take this the wrong way, I see you have a "blue" bios, that means you have a "lower" end mobo? or Prime z370-a or something? (it is a good mobo) that also means you probably have a 4 phase VRM (which gets toasty) If you install a fan on the vrm that is connected to your cpu fans so when you load it up it cools the VRM. (important)

ALSO, check of you have "AWARE adaptive voltage ON" if so disable that (you can still use adaptive vcore settings!

you might want to change switching frequency also, go up 50khz for stability, but you do need a fan for that.

EDIT: Run prime on 4.8 or whatever you run and feel the vrm with your fingers after 5-10 minutes, if it is hot as crap, it is probably what crashes our computer. it might be the cpu, but it might aswell be vrm temps. 5.0ghz 6cores with HT cooks vrms..

let me know how it went! good luck!

[Nate152]

Well, all cpu's aren't created equal, a good one will need less voltage while another will need more voltage for the same speed, you just have to find what yours needs.

Some stress testing programs may require more voltage than others. If all is good where it is (other than OCCT failing) you can call it good there, or increase the voltage until you pass OCCT.

I might call it good where it is since you're at 82c. If you delidded your cpu, temps would allow you to hit 5.0GHz.

[Cheesy86]

Cool. Sounds good guys. I will and see if I can pass Realbench for like 2 hours at 4.9GHZ using 1.32V instead of OCCT. Thats where I was at when I passed all the other stress tests. What do you think Nate? Would that be a good benchmark to call my system stable for 3D use and Vray rendering?

[kalle-m]

Cheesy86 wrote:
Cool. Sounds good guys. I will and see if I can pass Realbench for like 2 hours at 4.9GHZ using 1.32V instead of OCCT. Thats where I was at when I passed all the other stress tests. What do you think Nate? Would that be a good benchmark to call my system stable for 3D use and Vray rendering?

it might be voltage ripple, vrm temps, but these things you can do something about, a simple fan or raising switching frequency, using full phase mode and so on. it is not just the cpu and vcore that makes a overclock stable, every piece of hardware working to get power to your cpu must sing in harmony.

for example if you load your cpu and your phases work, they push 1.3 v interleaved in pulses of 250-500 khz. it is the space between the pulses that makes your voltage "vibrate" and when overclocking that might make or break your stability, asus has a built in setting for vrm switching frequency (and DRAM), if you go up 50khz at the time and check it just might work. some vrms has bigger voltage ripple than others and needs less frequency and some might need more. your cpu might be more sensitive to ripple who knows, there is a lot of things left to try. but no one needs 5ghz I run 4.7 because I like the temps more at that frequency 😛