Intel 6700K will not downclock consistently (EIST and C-States enabled)

[WWong10]

My 6700K will not downclock to 800Mhz consistently even though I have EIST/C-States enabled. The system only downclocks to 1600Mhz. If I go into my balanced profile power options, the "Minimum processor state" is set to 5% and the "Maximum processor state" is set to 100%.

If I force my maximum processor state to 20%, it will force the system to run at 800Mhz, however the moment I set it any higher it will clock higher than 800Mhz at idle. Once I have it at 40% or higher it settles to a 1600Mhz idle. If I leave it at default 100% max overnight, and monitor the clockspeed, HWMonitor will track that it does drop to 800Mhz momentarily at times, but again, it will level off at 1600Mhz usually at idle.

Observations:

At 1600Mhz my VID is 0.835

At 800Mhz my VID is also 0.835

Is it because the target voltage is the same at 1600Mhz and 800Mhz that the system will default to the higher clockspeed?

System:

6700K

EVGA Stinger Mini-ITX Mobo

Corsair Vengeance LPX 2x8GB 3000Mhz RAM

Windows 10

Settings:

- CPU core undervolted: -0.093V (this is stable /w Prime95 v28.9 24h Blend Test)

- XMP enabled

[idata]

Hello Edirol:

In regard to your inquiry, I just wanted to let you know that the overclocking or downclocking is actually not supported by Intel®, Altering PC clock or memory frequency and/or voltage may: Reduce system stability and use life of the system, memory and processoCause the processor and other system components to failCause reductions in system performanceCause additional heat or other damage; and affect system data integrity. Intel® assumes no responsibility that the memory, included if used with altered clock frequencies and/or voltages, will be fit for any particular purpose. Based on that, we actually do not have any documents related to this type situation, since Intel® did not perform those kind of tests on the processor. However I did some research in order to provide some information about this case, and according to the data sheets the processor is capable to work at 800Mhz and it should keep that clock speed if you set it up at that value. Here is the link where you can confirm that page 93: file:///C:/Users/albrodri/Downloads/desktop-6th-gen-core-family-datasheet-vol-1.pdf At this point, I think the best thing to do will be to wait for some other peers that might have done that in the past to share their experience on this thread, so we can confirm if there is actually a problem with the processor or if it might be related to the BIOS on the board. Any questions, please let me know. Alberto

[MRizz1]

Hi, I have pretty much the same issue on my MSI z170 Gaming m5 with a 6700K. By any chance did this issue only start occurring after the latest windows build 14393, the August update? Mine only started doing this after this update and I have isolated it to the intel speed shift causing issues. Try the following, be sure to back up your registry before making changes.

Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power

Change CsEnabled to 0 (previously 1)

Go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\8baa4a8a-14c6-4451-8e8b-14bdbd197537

Change Attributes to 0 (previously 1)

Restart and now you should have advanced power settings visible in Power Options > Change Advanced Power Settings. Under Processor Power Management you should now see Processor performance autonomous mode. This should be originally Enabled so change to Disabled.

[WWong10]

Hi Vortex,

This problem started even with the previous build. I installed a fresh win10 pro install sometime in July and it already had the problem. I tried the registry and power plan tweaks you suggested but it didn't seem to work. It's still stuck at 1600Mhz when idle unless I force it. Thanks for the suggestion though. I might look into this further, but my system is stable otherwise so it's OK like this for now.

[idata]

Hello:

Thank you very much to Vortex13 for all the information posted previously on this thread. I am sure it will be very helpful for Edirol and all the peers that are viewing this thread. Regards Alberto