Maximus ranger viii + 6700k - undervolting ?

[Mahaaveer]

Fellow members of ROG, Hola !

I am a newbie to ROG and overclocking. I recently built a PC with the following :

Intel core i7 6700k
Maximus ranger viii
Seasonic 620w modular PSU
Corsair vengeance 2 x 8 GB DDR4 2400 MHz
MSI GTX 970 OC edition
Corsair carbide 400r case
Cooler master Nepton 240m

As I said above, this is my first overclocking rig. I intend on keeping it for a long time.
I have noticed that 6700k (stock) core voltage fluctuates between 1.278 and 1.325, as seen on AI suite.
On stress testing, it can reach as high as 1.4. It causes extreme temperatures of 75 -80 degrees.
I did some digging and found out that stock voltages of skylake chips are quite higher than previous generations.

Anandtech's post on skylake overclocking suggests that to enter v core manually, even if ran on stock speed. In fact, they were able to run
6700k @4.3 GHz with core voltage of 1.200 !!! So I decided to get into action !!!


I set clock multiplier at 42 and v core @ 1.264v and It booted like charm. Ran realbench for 15 minutes and it passed the test. I don't need to reach 4.5 and above. My goal is to achieve stable clock @ 4.2 GHz With lowest temperature possible.

So, Can I go ahead and try 1.218 or 1.200 ? What are the consequences of undervolting the CPU? Is it safe ? What is test procedure ? How much time on realbench stress tests ? what is adaptive voltage? Am i reducing cpu's life ? Remember, my priority is life expectancy. I want to keep the pc as long as possible. Guide me through the process.


Thank you.

[Arne_Saknussemm]

Hi Mahaaveer 🙂

Yes, just keep reducing voltage until realbench wont pass...maybe drop 0.05 at a time to see where your CPU sits more or less and then fine tune 0.01v when you are round about where you need to be

Yes, undervolting in this sense is safe.

Speedstep is the intel feature that reduces voltage and clock speed of the CPU when it is idle and ramps you back up to turbo speed when the CPU is working...

If you set manual voltage you will notice the voltage does not decrease when CPU idles. This is fine for now while you look for your stable voltage for 4.2GHZ...however long term it is best to convert manual voltage into an adaptive voltage...so the CPU can take advantage of speedstep.
Very easy...find your manual voltage and enter it as Adaptive voltage....see this thread https://rog.asus.com/forum/showthread.php?83150-Arrrrgh!-I-cannot-figure-how-how-to-get-my-4790k-to-...!

[Mahaaveer]

Arne Saknussemm wrote:
Hi Mahaaveer 🙂

Yes, just keep reducing voltage until realbench wont pass...maybe drop 0.05 at a time to see where your CPU sits more or less and then fine tune 0.01v when you are round about where you need to be

Yes, undervolting in this sense is safe.

Speedstep is the intel feature that reduces voltage and clock speed of the CPU when it is idle and ramps you back up to turbo speed when the CPU is working...

If you set manual voltage you will notice the voltage does not decrease when CPU idles. This is fine for now while you look for your stable voltage for 4.2GHZ...however long term it is best to convert manual voltage into an adaptive voltage...so the CPU can take advantage of speedstep.
Very easy...find your manual voltage and enter it as Adaptive voltage....see this thread https://rog.asus.com/forum/showthread.php?83150-Arrrrgh!-I-cannot-figure-how-how-to-get-my-4790k-to-...!

Thanks Arne 🙂
Just to be sure, how much time is necessary to test the stability of the clock ? in realbench? and how about AIDA64 ?

[Chino]

It's a matter of preference. Some users test for hours, other days. It's up to you.

[Mahaaveer]

Chino wrote:
It's a matter of preference. Some users test for hours, other days. It's up to you.

An hour on realbench enough ? and what voltage i should start for 4.2 GHz ? Thanks !:)

[Arne_Saknussemm]

I just run 15 minutes....half an hour if I want to be super sure....I have yet to have an OC fail running anything...games, photoshop, benchmarks....after having passed RB....I can't say I use Aida anymore....