5 Replies Latest reply on Dec 12, 2013 8:21 AM by kevin_intel

    i7 2620M (2.7 GHz) multiplicator blocked at 16

    ndech

      Hello,

       

      I have a 2.5 years old sony vaio SA equiped with an i7 2620M and running on Windows 8.1.

      I experienced a few days ago unexpectedly low performances while playing a moderatly demanding game. After some investigations, I found out that the processor frequency does not go any higher than 1.6 GHz (on high performance, on sector and while running a processor benchmark). Even worse, as soon as I start a game, the frequency drop to 0.8 Ghz and sometimes after a few minutes even lower.

       

      I tried multiple tools to investigate the cause of the problem and test some hypothesis :

      - The temperatures are normal : about 50 in idle (in high performance) and about 70 while running a benchmark. I think I should be able to go at least 20°C higher than that, so I think that rules out overheating induced throttling. Am I right ?

      - I can not find a tool that allow me to force the multiplier to a specific value, it is continuously fluctuating, never higher than 16 (I should be able to reach 27).

      - I installed the latest bios from my laptop manufacturer and all drivers and utilities related to the processor. No change whatsoever.

       

      I'm considering dismantling the computer to clean up the dust, but as the problem does not seem to be heat related, I don't expect any improvement.

       

      An other idea might be that it is related to my upgrade to Windows 8.1 ? I do not know for certain how it was before, but I never noticed any problem. Are there knowns bugs around this upgrade ?

       

      Thanks in advance for any form of help ! Let me know if you need more information or if I can try something.

        • 1. Re: i7 2620M (2.7 GHz) multiplicator blocked at 16
          kevin_intel

          Hi ndech,

           

          The temperature you mention the system reaches seems to be completely normal meaning that the performance should not be affected with these temperatures.

          At this point there are no tools from our side to increase the processor clock speed but I recommend you running the Intel® Processor Diagnostic Tool. This will diagnose and will test the internal processor components and will let you know if there is something wrong with it. You can download it at the following link:

           

          64 Bit:

          https://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=19792&keyword=Processor+Diagnostic+tool&DownloadType=Utilities%2c+Tools+and+Examples&lang=eng

           

          32 Bit:

          https://downloadcenter.intel.com/Detail_Desc.aspx?agr=Y&DwnldID=19791&keyword=Processor+Diagnostic+tool&DownloadType=Utilities%2c+Tools+and+Examples&lang=eng

           

          I also recommend you checking with the computer manufacturer the Operating System compatibility with your unit

          • 2. Re: i7 2620M (2.7 GHz) multiplicator blocked at 16
            ndech

            Hello Kevin,

            Many thanks for your answer.

            I ran a few more tests yesterday evening (Belgian time ) after posting my message, including the Intel Processor Diagnostic Tool that ran successfully.

            I understand you cannot recommend third party tools, but i used ThrottleStop 6.00 to monitor frequencies and check the value of the multiplier and modulations in various situations. When the system is idle, the frequency fluctuates and can reach 2700 Mhz if I enforce it. But as soon as I run a benchmark or launch a game, in 2 seconds the multiplier drop to 8 and the system throttles at about 800 Mhz, even if it the processor is running at 100%. Has this value of 8 for the multiplier a specific meaning ? Like a security threshold to prevent overheating or damages due to under powering (both unlikely as I use the stock charger and the temperatures hardly reach 75°) ?

            Windows 8.1 is supported by my computer according to the manufacturer and Sony provide adapted drivers.

             

            I updated and reset the bios, I will try to reinstall a few drivers but I have not much hope.

            Unfortunately, my system is 2.5 years old and as such out of warranty.

            My last option is a clean reinstall but it is not a very good time for me to do it and I'm still not even sure that it would solve the problem.

             

            If you have any idea or if any of you has a similar experience to share (with a happy ending preferably ), it is most welcome.

            Thanks in advance.

            • 3. Re: i7 2620M (2.7 GHz) multiplicator blocked at 16
              kevin_intel

              Hi ndech,

               

              I recommend you checking the thermal solution you are using. If the system is 2.5 years old, a good step is to clean the thermal paste and add new thermal paste. Also taking the Fan heat sink and setting it up again can help on this situation.

              • 4. Re: i7 2620M (2.7 GHz) multiplicator blocked at 16
                ndech

                Thanks for your answer Kevin.

                 

                Unfortunately, as it is a laptop, accessing the CPU to replace the termal paste should be quite a risky challenge. I'll consider it, but only as a last resort solution.

                 

                Just a bit of new info since my last post, I made a clean reinstall of Windows 8.1. My hopes were up, but winthout installing any specific drivers the results are still the same. Just for the sake of completeness, I'm going to reinstall Windows 8.0 just to see if the problem is not related to the update.

                 

                In the following picture, you can see the load on the CPU while running a benchmark from windows 8 task manager. As you can see, the throttling is obvious but the system oscillates immediately between periods of 2-3 seconds at full power, then a few seconds of throttling and the frequencies go back up again. (Temps are around 70° the whole time).

                 

                I have a really hard time understanding what is going on.

                If you have another idea, you would be my savior

                Thanks !

                CPU.jpg

                • 5. Re: i7 2620M (2.7 GHz) multiplicator blocked at 16
                  kevin_intel

                  Hi ndech,

                  At this point, since you have tried the steps provided for your OEM computer I recommend you contacting the computer manufacturer for them to help you and replace the unit if necessary.