7 Replies Latest reply on Sep 9, 2011 11:16 AM by Gorzawski

    Core i7 2600k -  Temperature rise to 51°C and it reduce clock


      I have a i7-2600K with a large tower heatsinks (Alpenföhn chunks) on an ASUS P8P67-M Rev. 3 Mainboard

      8Gbyte Ram (OCZ) under Windows 7 64bit with Service Pack 1 .


      I monitor the temperatures of the CPU with RealTemp 3.60 and the ASUS AI Suite II
      I calculate raytracing images with POV-Ray 3.7 which utilizes all cores with 100%.
      If the temperature exceeds 51°C it reduce the clock to 3.4 GHz to get back to 3.8GHz
      to immediately reduce to 3.4 GHz. etc. etc.
      This also happens when I work with a multipliers 38 up to 48, even when 51°C where reached it reduces
      to 3.4 Ghz and back to max turbo mode.

      The maximum temperature of  98°C seams still very far away. is it a warranty issue , or what goes wrong?



        • 1. Re: Core i7 2600k -  Temperature rise to 51°C and it reduce clock

          g-gerd,  I'm not sure I understand your description of the issue, but I'll try to help you.


          First, where did you get the idea that the maximum temperature of an i7-2600K is 98C?  The maximum temperature, called Tcase, for your CPU is 72.6C.  Check the specifications for your CPU here:




          Second, are you certain that all the CPU's cores and threads are at 100% usage constantly when you use that software?  How are you monitoring the CPU usage?


          I have an ASUS P67 mother board and i7-2600K CPU, and use AI Suite II.  If you use another temperature monitoring program at the same time as AI Suite II Monitor, one or both of those programs can display incorrect temperatures, as they become confused or the data they read is bad for some reason.  My point is your temperature reading of 51C may not be correct.  Use one program at a time.


          The behavior of your CPU's frequency when using Turbo Boost depends upon the settings in your EFI/BIOS.  One thing that affects this is Enhanced Intel Speed Step (EIST), the power saving feature.  If that is not enabled, the maximum Turbo frequency can be limited, which may be your problem.  That is just the way this CPU is designed, and using EIST does not hurt performance.


          Intel did not intend Turbo Boost 2.0 to be setting the CPU clock at it's maximum frequency all the time, although some mother boards ignore that and let the user keep the CPU at 3.8GHz or higher, from the standard frequency of 3.4GHz.  Your ASUS board should allow you to use the CPU at 3.8GHz or more, if the EFI settings are correct, and the temperature is not to high.


          Seeing the frequency of the CPU change is not unusual when using Turbo and the program running is not at 100% CPU usage, that is normal and not a problem.


          If you are very sure about the amount of CPU usage, and the temperature of the CPU, then you need to adjust things in the EFI before deciding the CPU has a problem, which is usually not the case.

          • 2. Re: Core i7 2600k -  Temperature rise to 51°C and it reduce clock

            Hi parsec,


            thank`s for your answer and your suggestions.


            you`re right with the Tcase Temperature of 72.6C, i read this higer Temperature in a programm called core temp 0.99.8, but the

            intel spec over rules this.

            I measure  100% all cores with the windows performance monitor and the frequency with the intel tool to monitor turbo boost 2.0

            The Temperature with AI Suite II and not in parallel with another tool. I only use Real Temp to test too.


            I bought this processor because it is so fast. My raytracing pictures are intense and they need up to 3 days to calculate with 100% using all cores.

            I need as much  frequency i can get. 30% more means to save one day !

            I will not accept that turbo works only for a few minutes even when the temperatures stay inbetween normal borders.

            Why is my cpu not going over 51C ? Which settings causes this ? I reset the mainbord bios to optimized defaults but it will not help.


            I asked asus what goes wrong and they tell me that first : its normal cpu behavior and second : please try another cpu to test.

            for me : first : it is not normal   and second : this costs too much


            I think the cpu is no good.

            • 3. Re: Core i7 2600k -  Temperature rise to 51°C and it reduce clock

              g-gerd,  I understand your usage of POV-Ray better now, and given how long it takes, you need all the CPU speed you can get.  Although your CPU has unlocked multipliers, Intel may say that they only guarantee the specified Turbo frequency of 3.8GHz, and even that is dependent upon temperature.  I have had my i7-2600K running at 4.2GHz at 62C using linpack 64, without the CPU frequency dropping from that value, although I did not run that for 24 hours, much less days.  Also, my testing does not have all cores at 100% all the time, which may be significant.


              You're the second person I've seen on this forum whose i7-2600K behaved as you describe, and I'm sure you have read that many users have their '2600 running at multipliers of 45 and above for long periods of time.  You are also likely aware that CPUs of the same type can vary in performance, some over-clocking much better than others.  Before deciding your CPU is not one of the better ones, you should go back to the EFI/BIOS and see what can be done.


              Since you have an ASUS P67 mother board, I'll assume the EFI settings are similar if not the same as my ASUS board.  You may have done some of these things, but this is what works for me.  First, you should have EIST enabled, as well as C1E, not Auto, Enabled.  C3 and C6 can be Auto.  In AI Tweaker, I leave BCLK at Auto/100, you won't get much out of changing that, plus it can cause instability elsewhere.  All OCing is done with the Turbo multipliers only, no change in the CPU base frequency of 3.4GHz.  I use the Per-Core rather than All-Core multiplier setting, for example setting Core 1 to 43, and all others to 42.  PLL Overvoltage is set to Auto, and I do not change any CPU voltage settings, all are Auto.  I do use the XMP setting for my memory, but that is all, no other OC settings.  Everything else is at default settings.  I use a Scythe Mugen II CPU cooler, which is similar to yours.  I have many fans in my case, a midrange video card, and use either 660W or 750W power supplies.


              I use either AI Suite II's Monitor for temperatures, or HWiNFO32, but not at the same time of course.  I don't use SpeedFan, as it shows false, to low temperatures IMO.  What did you try in the EFI for OCing, and what do you do that is different?

              • 4. Re: Core i7 2600k -  Temperature rise to 51°C and it reduce clock

                Hi parsec,

                my power supply is a super flower 700W piece and my pc-door  is open for best cooling during testing.

                up to now i have tested a lot of different setting in EFI Bios but no better result.

                My latest testings in EFI Bios which works a few minutes more was :

                advanced mode ,

                AI-Tweaker :

                AI Ov.Cl.Tuner :manual, BCLK/PEG :100.00 ,

                turboratio: by per core , first to fourth core 46 , int. pll overvolt. :enabled , mem frequenz : auto ,

                dram timing contr. : no change ,

                cpu-pow mang. : cpu ratio : 30 ( ! ) , EIST : enabled , turbo : enabled , turbo mode params : auto ,

                ofset mode sign : - , cpu ofset volt. : 0.010  ,dram volt : auto , vccio : auto pch : auto , loadline cal. : diabled , cpu spread spr. : diabled .


                cpu ratio : 30 , other settings standard

                This results in 4.6Ghz for 4 to 5 minutes with temperatures 54C to 55C

                then dropping to 3.00 Ghz an rising again to 4.6Ghz and so on.


                My decision is to test a different board , no asus ,( a friend of mine will build a new pc ) and i will test my cpu there.

                Maybe i can report my experiences later.

                • 5. Re: Core i7 2600k -  Temperature rise to 51°C and it reduce clock

                  I've got the MSI P67a-GD65 running the 2600K at 4.2 ghz and "lending out" CPU time via BOINC to the Milkyway@home project.

                  They DO utilize everything -- crank everything up to 100% -- and temps can climb.  The mobo comes with some nice utilities including a hardware monitor that shows you core temps on the CPUs but no apparent package temp.  It would show core temps in the mid 90's (!?!?!) and so I backed the CPU intensive stuff off.  I put a bigger CPU cooler on it (thermaltake spinQ) and it really helped.  I can run 70% sustained all CPUs (8 bars on task manager hanging around 70% +/-) with the core temps staying below 80's. Closed case, office temps at home about 70.  It's getting warm in the office now (central MA), so we'll see how long this lasts.


                  BTW -- you might want to think of applying one of these video GPU's to your compute intensive task.  I've got an NVidea 550Ti and the software from the BOINC/Milkyway uses it's 192 cores.  The board itself is good for almost 3/4 teraflop -- and it's only mid-range!.  That's got to be about 10 times what the Intel 2600K can do flat out (for the specialized computations, of course).  So, if your 3 day test could be brought down to about 7 hours...

                  • 6. Re: Core i7 2600k -  Temperature rise to 51°C and it reduce clock

                    Hey i just dumped into this post. I know it's kinda old but anyway.! It's quite normal. Intel turboboost only blows up multipliers etc when needed and if headroom is available.. Disable Intel Turboboost and then OC ur CPU to 3.8 Ghz and see what happens... Base frequency should be stock and multiplier should be at 38.. Make sure that NO greenpower things etc that saves power will interfere with ur OC.! Otherwise it might be the real cause when running big loads of data.!


                    If this is running fine at about maximum 60 c with a stock cooler then there should be no problem with ur CPU. (Btw, make sure that fanspeed and CPU heat ratio is high enough. Otherwise increase the fan speed to 100% and see if THAT works)


                    Oh...! Use hwmonitor instead.! It's much more precise and shows max, minimum and realtime temps of all 4 cores individually. Run it in the background and do your work and then check the temps after.


                    If ur problem is already solved, i guess i just hope somebody else find this somehow usefull.. O_O

                    • 7. Re: Core i7 2600k -  Temperature rise to 51°C and it reduce clock


                      right its realy old posting and solved.

                      It takes more time to test with an other (better) mainboard than i guess.

                      Solution was first to take this better motherboard because CPU runs fine.


                      Secondary solution : when i cool the powerregulators on the mainboard with an extra fan

                      my original board is working day by day without reducing clock speed.

                      (This solution came as an answer from the  German Ct Magazin, i asked too.)

                      So i use my original board up to now without any problems and full O.C.speed 4.5 Ghz

                      max temp. about 68 to 70°C watercooled.


                      maybe this will help others too.