i7-6850K stuck at 3.8Ghz

[WaterlooDude]

Hello Friends!

I have had my 6850k running at 4.4Ghz stable for almost two years. But that's until I ran into the following problem a few days ago.

The CPU seems to be stuck at 3.8Ghz in windows. I tried to reset the bios, and overclocked it back to 4.4Ghz.

The bios clearly indicates the CPU is running at the desired frequency. However, once I boot into windows, the frequency drops down to 3.8Ghz on all cores except the preferred core at 4.0

Here is a topic I found on Reddit which describes the same issue I have. 

Cheers.

 

[barondeau]

have you tried removing the Cmos battery?

 

[WaterlooDude]

1 minute ago, barondeau said:

have you tried removing the Cmos battery?

 

Nope I have not.

Coincidentally 3.8Ghz is the default turbo boost frequency for 6850k. But my overclock should override that setting anyways. 

I am starting to think it's a software issue. 

[barondeau]

Then you are going to have to either do a bios update, hope resetting your cmos battery works, or just deal with it 

[WaterlooDude]

17 minutes ago, barondeau said:

Then you are going to have to either do a bios update, hope resetting your cmos battery works, or just deal with it 

I tried to M-flash the bios, and it worked! Thank you for the advice man. 

[AmbiguousShawn]

Please forgive my poor English. I am from a non-English-speaking nation.

Hopefully I can help you with this issue. I already fixed it.

The key word is microcode!!! That's very important! The microcode updates ruined the overclock on x99 platform. Clean it from your PC, your overclock comes back.

 

1. Find the KB4100347 update in windows updates, uninstall it.  DO NOT RESTART NOW! 

2. Download Show and Hide Updates

    After hiding this updates, you can restart your system. Please make sure KB4100347 will not show up after restarting.

3. If your overclocking is running at what you expect, that's perfect. 

    If not, let's continue.

4. Check your BIOS version. My motherboard is ASUS ROG STRIX X99 GAMING. I was using the BIOS version 1902.

    The 1902 version updated the microcode for motherboard. So we don't need this version.

   

    Download a previous version BIOS and load it. After that your overclocking will come back.