6900k overclocking questions

[Paladone]

My current CPU is an i7 6900k and lately I've been trying to overclock it. I don't have a lot of experience with overclocking so I was wondering if I could please get some advice.

I was able to stabilize the chip at 4.3GHz/1.280V and also at 4.4GHz/1.390V. My RAM is currently running at 3000MHz, which is its default frequency. When the CPU is stable at 4.4GHz/1.390, it gets very hot. Using P95 it runs at around 60 degrees celsius during a blend test, but when I ran an In-place large FFTs test it spiked to around 75-95 degrees, varying by core, so I stopped it ASAP. On the other hand, @ 4.3GHz/1.280V the temperature during an In-place large FFTs test peaks at around 65 degrees celsius. My first question is therefore, should I just stick with 4.3GHz/1.280V, or is the latter 4.4GHz/1.390V acceptable so long as the temps aren't consistently that high?

One thing I noticed was that for around 20 seconds after logging in at either OC, the computer would display the spinning loading wheel and seem to freeze up a bit; there would be a significant delay in the response time of my keyboard and also mouse. This leads me to ask, is this because the clock is not actually stable, or do I need to adjust any other settings; ring ratio etc.?

Cheers

 

[broken pixel]

Stick with the 4.3GHz settings.

 

[argon]

You'r cpu is better than mine , as i can do only stable at 4.2 at a lot of 1.31v blend

What P95 you're using ? I'd stick with 26.6 , don't use powerful p95 they are too much demanding (there isn't a software in the world that use FMA3 instruction) I thinks thats why you're getting all that very high temp!!

 

[slozomby]

"4.3GHz/1.280V and also at 4.4GHz/1.390V." that's a huge difference between 4.3 and 4.4.

if that's correct i'd stick to 4.3

 

[HammerON]

I would stick with 4.3 @ 1.28Vcore. Mine is running at 4.3 @ 1.3Vcore.
The 6900K and 6950K are not great overclocking CPU's from what I have read.

 

[FR@NK]

Does your bios tell you the core Intel thinks will have the most headroom? I cant find much info from the manual for your board.

This is what it looks like on an asus: See how core 2 is marked? That core should overclock the best.

Dont try to get all the cores running at the same max freq as each core will have more or less headroom. Each core will have a max overclock so locking them all together may not get you past 4.3GHz. Remember games dont use all these cores anyways so its better to have afew fast cores compared to just all cores at a lower speed. Also you cant use a fixed voltage as its better to let each core use whatever voltage is necessary by using offset/adaptive mode.

Also notice the AVX offset, do you see this option in your bios? Intel knows that AVX instructions stress the CPU more then normal and will lower the ratio while doing them. I have it set at 2. This will get you a higher overclock yet still be stable over all workloads.

And install the turbo boost driver. This will tell windows which cores run the fastest and to schedule demanding work to these cores first.