10 Replies Latest reply on Mar 5, 2018 5:27 PM by Intel Corporation

    8700K incorrectly functioning Turbo Boost multiplier after updates

    t0yz

      Hello,

       

      I will try to keep it as concise as possible.

       

      - 8700K should boost up to 4700MHz/47x per one core. This is very easy to test if functional, through a monitoring app such as HWinfo64, High Performance power plan and a very light workload (i.e. lave the PC idle for a short while)

      - expected, normal result on a correctly functioning CPU is that HWinfo64 will register the 47x multiplier and 4700MHz. As Turbo Boost is opportunistic, it is obviously not a stable 47x, but that doesn't matter  - what matters is that at times, the properly cooled and installed CPU will reach 4700 MHz.

      - the expected result occurs on a fresh Windows 10 x64 FCU (1709) installation. The CPU works correctly - 47x multi is reached

      - after applying the first batch of updates (I'm positive it includes some Meltdown/Spectre mitigations, as before these patches were released my 8700K functioned normally. This is why I performed a fresh OS reinstall, to see if I can remedy the issue. No luck), the

      CPU is only able to boost to 4600MHz/46x, regardless of workflow and conditions. Reinstalling the OS fixes it, but obviously you're left unpatched

      - bug should be very easy to reproduce

       

      Additional info I am not 100% certain of:

      - the culprit is the Core0 multi. Through BIOS and MSI Command Center (app that allows you some OC inside the OS) I tried setting it higher than the default 47x. It does not work. That core will always boost to 46X max after updates

      - allowing 2,3 or more cores to boost to 4.7 GHz fixes it. If you want to test this, I suggest using 3-4 cores, it seems that it would appear faster on HWinfo64 (again, High Perf power plan, leave it idle, or browse web/do something light).

      - something like MCE (multicore turbo, has different names depending on vendor) would function normally. What is affected is the default, out of the box, non-OC 8700K.

      - OC works as long as you don't try to OC Core0 to higher multis. That would simply not work, it remains at 46X. Any OC would have to be performed for 2 cores, as it seems to not possible (at least on my board) to use a 45x multi on Core0 and a 47X on Core1, for example

       

      Would be nice to see an acknowledgement of this bug. I already confirmed it with others using 8700K at MSI forums and reported it to Microsoft as well, although they didn't seem to care much. Would also be nice to see it confirmed from other users.

       

      Keep in mind Intel, this means your CPU performs worse out of the box, additionally to the Spectre/Meltdown impact, and it would affect buyers that will feel they didn't get what was advertised/seen in web reviews.

       

      Thanks!

       

      Specs:

      8700K, MSI Z370 Gaming Plus (BIOS 1.12, but it occurs on earlier BIOS too), GTX 1070Ti, 16 GB 3000 MHz DDR4 RAM.

       

      The patches that were applied:

      245d07e2-35ae-4072-aad2-e0d233882dac.jpg

      How it looks on a fresh OS (correct 47x):

      correct.PNG

      How it looks on a patched OS:

      borked multi.PNG

        • 1. Re: 8700K incorrectly functioning Turbo Boost multiplier after updates
          t0yz

          Nobody has to say anything about this?

           

          The issue persists and is INCREDIBLY easy to replicate with 100% accuracy. Steps:

           

          - load Optimized Defaults in your BIOS  - just to make sure the CPU runs at Intel's default parameters

          - create Windows 10 FCU x64 DVD/USB bootable with something like Windows Media Creation Tool

          - install a fresh Windows 10 x64 Pro FCU

          - check 8700K CPU frequencies with HWinfox64 or other tool. To allow the CPU to reach max turbo, please use High Performance power plan and leave the PC to idle for a short while, so the CPU cores can boost as high as possible because of the very light workflow.

          - you should see the cores going up to 47x/4700MHz, which is the correct behavior.

          - Windows should already have started to download a few updates in the background. After it's done, it will want to reboot. Do so, wait for the updates to be installed.

          - check the frequencies again, now the CPU will run at a maximum of 46x/4600MHz, which is 100 MHz lower than normal, obviously.

           

          You can even check the botched Core0 turbo/multi by setting other multis for the first core, like 48, 49, 50 - it won't matter. The CPU won't boost to those after patches. However, if you set the multi to TWO cores, like Core0-Core1, the Turbo Boost will suddenly work as it should.

           

          I mean, I'm not sure what other info I can offer. However, if anyone from Intel feels that they can't replicate it and need more details, i would be happy to oblige.

           

          I've also posted about this on Reddit and some 8700 (non-K) users conformed their CPUs not boosting properly either. Same info was also posted on Microsoft's forums.

           

          Would love to see an acknowledgment of the issue from Intel as well, so we can know the bug is known and worked on.

           

          Thanks.

          • 2. Re: 8700K incorrectly functioning Turbo Boost multiplier after updates
            Intel Corporation
            This message was posted on behalf of Intel Corporation

            Hi Thank you very much for contacting the Intel® Processors communities and for providing all that information and the pictures. We will do our best to assist you with this scenario.
             
            In regard to your inquiry, just to let you know, we will do further research on this matter, as soon as I get any updates I will post all the details on this thread.
             
            Any further questions, please let me know.
             
            Regards,
            Alberto R
             

            1 of 1 people found this helpful
            • 3. Re: 8700K incorrectly functioning Turbo Boost multiplier after updates
              t0yz

              Thank you, it's all that matters. regardless of the recent Spectre/Meltdown debacle I know Intel is a capable and great corporation, so I am 100% positive that you will fix this.

              Your response is much appreciated.

              • 4. Re: 8700K incorrectly functioning Turbo Boost multiplier after updates
                Intel Corporation
                This message was posted on behalf of Intel Corporation

                You are very welcome. Thank you for your feedback. I have sent you a PM, please verify your inbox.
                 
                Any questions, please let me know.
                 
                Regards,
                Alberto R

                 

                • 5. Re: 8700K incorrectly functioning Turbo Boost multiplier after updates
                  t0yz

                  Thanks for the PM, but this is a completely different issue.

                   

                  Even in your linked document, it is saying that the 8700K has a 4.7GHz. This is also NOT about the Meltdown patch. It's one of the earlier patches that is applied BEFORE the Meltdown patch.

                   

                  I will repeat what I have already stated twice.

                   

                  - this is about a GOOD, WORKING CPU, that WORKS NORMALLY (!!!!!) on a fresh OS - Windows 10x64 Pro FCU

                  - after one of the patches I have linked in first post screenshot, rebooting, the CPU NO LONGER uses the correct Turbo Boost, specifically for Core0

                  - this is not about the CPU reaching other limitation, like thermal/power/voltage or something

                  - this is EASILY tested and reproduced, as I described above

                   

                  The 8700K should reach 47X/4700MHz multiplier. If it does not, something is wrong. As Intel's driver patches and a few Microsoft Cumulative Patches are the one and only change that were applied on my PC, Iassume one of them is at fault

                   

                  Again, this is NOT related to Meltdown (KB4056892). That patch, while indeed affecting performance, doesn't affect the CPU frequency/multiplier.

                   

                  There are no other updates to apply to my PC to fix this. I have the latest everything, drivers, OS, patches, BIOS.

                   

                  What needs to be done is one of your engineers reading what I have written, follow the reproduce steps, acknowledge the bug and fill it in whatever bug tracking system Intel has, and in case it's a Microsoft bug, work with Microsoft to fix it.

                   

                  It is Intel's best interest that your CPU work as intended out of the box. As things are now, one cannot achieve the Intel intended functionality even with overclocking, as the Core0 multiplier IS NOT WORKING AT ALL and you are maxed at 4.6GHz instead of 4.7GHz unless you are boosting more cores than one.

                   

                  Kindly forward this issue to somebody able to test&replicate. Without clear acknowledgement of the bug, we won't see a fix, and this is what I want to avoid.

                  • 6. Re: 8700K incorrectly functioning Turbo Boost multiplier after updates
                    Intel Corporation
                    This message was posted on behalf of Intel Corporation

                    : You are very welcome.   Thank you for providing those details, I sent you another private message, please check your inbox.
                     
                    Any questions, please let me know.
                     
                    Regards,
                    Alberto R
                     

                    • 7. Re: 8700K incorrectly functioning Turbo Boost multiplier after updates
                      t0yz

                      Found the culprit!

                       

                      It was actually a setting that was turned on somehow by one of the updates - Let Cortana respond to "Hey Cortana"

                       

                      Having this setting turned on will result in the CPU never boosting to max for some reason. The workload from it so small you can't even quantify it with Task Manager/procexp, yet it seems enough that your CPU will never boost.

                      • 8. Re: 8700K incorrectly functioning Turbo Boost multiplier after updates
                        Intel Corporation
                        This message was posted on behalf of Intel Corporation

                        : Perfect, thank you very much for letting us know those results and for sharing the solution with all the peers in our communities, we really appreciate you took the time to do that. It is great to hear that problem got fixed.
                         
                        Any other inquiry, do not hesitate in contact us again.
                         
                        Regards,
                        Alberto R
                         

                        1 of 1 people found this helpful
                        • 9. Re: 8700K incorrectly functioning Turbo Boost multiplier after updates
                          xenphor

                          Are you sure that is what solved it? I have an 8700k with an Asrock z370m itx a/c motherboard and have noticed for awhile now that it is never able to hit the 4.7ghz boost clock. I have emailed Asrock about this and used their bios settings but it did not solve the issue. I am able to hit 4.6ghz at the desktop with high performance power settings as you said, but that Cortana option was already disabled on my install. I tried enabling it and disabling it but still can't get to 4.7ghz at high performance with no other applications running.

                           

                          I have not tried running any tests before Windows automatically installs updates to see if I can reach 4.7ghz so it may also be an issue there as well.

                           

                          edit: I've since installed Windows 7 and tried high performance before installing any updates and saw very briefly spikes to 4.7ghz which I did not see previously. After updating fully I am also seeing that it is not able to boost to 4.7ghz at the desktop anymore.

                          • 10. Re: 8700K incorrectly functioning Turbo Boost multiplier after updates
                            Intel Corporation
                            This message was posted on behalf of Intel Corporation

                            Hello xenphor
                             
                            Thank you for joining the community.
                             
                            To assist you better could you go ahead an create a new thread with your situation.  
                             
                            Thank you.
                             
                            Regards,
                            Leonardo C.