1 2 3 Previous Next 32 Replies Latest reply on Feb 12, 2016 6:35 AM by ivanu_intel

    I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95

    OKYHb

      Hello,

      I've just put together a system with DZ68DB Intel motherboard and I7-2600K CPU. Right now: no overclocking, liquid cooling. When I'm testing it by running Prime95 torture test, the CPU speed drops to 1600Mhz shortly after the start as shown by "CPU-Z". The temperatures at this time are in low 50's C as shown by "Core Temp". What could be wrong?

      Thanks

        • 1. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
          OKYHb

          Ladies and Gentlemen,

          The question of mine appears hard to answer. Maybe it was the way it's composed or nobody has an explanation for my problem so far. At this point, I will greatly appreciate any ideas regarding the issue, even though they are not based on the real experience or deep understanding. Just give me something to try and to think about please.

          Thank you,

          OKYHb

          • 2. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
            ptsheahan

            Hi OKYHb,

             

            the sandy bridge cpus will throttle themselves to 1600mhz when not under heavy load. I understand that prime is supposedly stress testing the CPU but it seems like either theres a problem with the motherboard settings, or that the prime tests you are running are not triggering the fullspeed and turbo modes.


            Think of it this way, the cpu sits at 1.6 all the time when not in use (this is built into cpu management), then under load it will jump up to its native 3.4 ghz, then after it decides its under 'heavy' load it will kick into turbo mode and overclock all 4 phases to 3.8ghz.

             

            1. Make sure prime is set to run 4 threads, and play around with different stress cycles (though prime is not likely to be the problem). Its possible you are looking at the clock speed of one core which is idle whilst the other is at full load due to not running prime on all cores.

            2. Try OCCT. See if the cpu still sits at 1600.

            3. Confirm the cpu program you are using to read the cpu is REAL TIME. Some programs will probe the cpu at initialization but will not update speeds real time. Try CPUid, CPU-Z or similar program with real time clock and open the real time clock window. You should see the frequency moving up and down in a real time clock viewer even sitting idle at 1600, (1599.9, 1600.1, 1600.0 and so forth)

            4. Failing all this, go into bios and DISABLE turbo boost and all smart frequency controlling and stepping settings. Make sure the CPU is set to sit at native 3.4 ghz. With some motherboards means disabling ALOT of crap, anything that says thermal, stepping or automatic anything really relating to the cpu except voltage (messing with this could damage your computer.

             

            Regards, Paul S

            • 3. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
              OKYHb

              Paul,

               

              Thanks for your reply.

              1. In my case, Prime95 was set to 4 threads when hyperthreading is disabled, and 8 threads with hyperthreading.

              2. I will check out OCCT.

              3. I was using CPU-Z.

              4. I did try to disable turbo boost, put my CPU in high performance mode, disable SpeedStep and C1E. The CPU frequency still drops. It's not just Prime95, I was doing video encoding and the speed dropped. I ran PCMark7, the speed dropped while doing the same kind of operation.

              I'm in touch with Intel support now. They couldn't reproduce my problem. At this point, I believe my motherboard is defective.

               

              Thanks again,

               

              OKYHb

              • 4. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                Peter

                Hi there,

                 

                I got exactly the same problems. From the first day on.

                I would like to add a little more detail:

                 

                - the CPU throttles down to 1600 MHz (which is unacceptably slow when doing some heavy work) as soon as the sum of all 4 cores exceeds 250°C (at least approximately). And it comes back to 3400 MHz at may 225..230°C (this one is more difficult to watch). It toggles than back and forth.

                 

                - reducing the core voltage down to the point where it is just booting delays the thermal throttling and shortens the periods where it is at 1600 MHz. But it is impossible to run it at the nominal CPU clock speed for a longer time. Fiddling around with the power and current limits doesn't change the situation either.

                 

                - I got a pretty decent water cooling using a Watercool Heatkiller 3.0 cooling block. And I have a case fan blowing on the socket area to cool the components of the voltage converters - their temperature changed from *very* hot to moderate after the installation of that fan.

                 

                - The case is a big Yeong-Yang cube YY-420 with plenty of air ventilation.

                 

                - Enermax Platimax 500W PSU. Asus GTX-650TI video card.

                 

                - Bios is up to date.

                 

                The issue seems to be present from the very beginning of the board ... http://www.tomshardware.com/reviews/z68xp-ud3-dz68db,2980-17.html ... seems like this was the worst Intel board I ever got. :-(

                 

                Booting is often extemely slow. I have to wait for maybe 30 seconds until the board hands over to the OS. But after that everything runs rock stable. The mild overclocking I tried so far is working just as stable as standard clock speed. Just that the temperature barrier is hit way sooner.

                 

                If there was some magic cure... it would be very welcomed. Otherwise I dump it into the waste bin as soon as the Ivy Bridge EP is out...

                 

                Best regards

                Peter

                • 5. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                  vbaderks

                  I also have the DZ68BC with a i7-2600K and lots of issues with this board (i7-2600K is detected as an unsupported) CPU for example, since BIOS 37).

                   

                  It seems however that some problems are a combination of the hardware and the BIOS. You could contact Intel for a replacement. Or buy an alternative used Z68\Z77 board, probably the cheapest option.  

                  • 6. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                    Victor_Intel

                    Hello,

                    I recommend you guys to run the Intel® Processor Diagnostic Tool and keep your speed monitor open while you run it, you will see the frequencies of the processor raise.


                    http://downloadcenter.intel.com/SearchResult.aspx?lang=eng&keyword=Intel%C2%AE%20Processor%20Diagnostic%20Tool


                    Regards


                    • 7. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                      Peter

                      Victor,

                       

                      Thank You for Your response!

                      I ran the tool, and it told me "pass" in all subtests.

                      The starting temperature was 66° below limit before the test and 56°C after the test.

                      My next action is to install a second radiator to get the CPU temperature under load

                      down.

                      Btw, during the test Coretemp showed some garbage, i.e. it stated a power consumption

                      of 799 Watts... Temperature at the end of the test was at about 59°C.

                       

                      But to me this looks all pretty inconspicuous.

                       

                      Best regards

                      • 8. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                        soundroad

                        Hello,

                        I have the same issue I7-2600K on DZ68DB, BIOS 0043!

                         

                        I turned off SpeedStep, C State, Turbo Boost in BIOS settings, but CPUID shows me:

                        "CPU Clock - 1596.x , Multiplier - 16x jumping to CPU Clock - 3392.x, Multiplier - 34".

                         

                        How can I get the constant CPU speed?

                        Thanks,

                        Evgeny

                        • 9. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                          ivanu_intel

                          Hi,

                           

                          Please Access the BIOS press F9 on your keyboard to set the BIOS to defaults and then press F10 to save the changes.

                           

                          Did you try running the Intel® Processor Diagnostic Tool from the link Victor_Intel posted above? If you run the Intel® Processor Diagnostic Tool please post results here.

                           

                          At the top of the Window is a Menu Bar. The “File” Menu allows you to open the TestResults.txt file using Notepad.

                          IPDT.PNG

                          Best regards,

                           

                          Ivan

                          • 10. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                            soundroad

                            Hi Ivan,

                            thanks for your answer!

                             

                            I've changed the BIOS settings to default and did the Intel Processor Test. The results are below:


                             

                             

                            ---------------------------

                            --- Testing Processor 1 ---

                            ---------------------------

                             

                             

                            --- IPDT64 - rev  2.20.0.0.W.MP ---

                             

                             

                            --- Start Time: 01/21/2016 09:48:00---

                             

                             

                            --- Skipping Config ---

                             

                             

                            --- Reading CPU Manufacturer ---

                             

                            Expected --> GenuineIntel

                            Detected --> GenuineIntel

                            Found --- Genuine Intel Processor ---

                             

                             

                            --- Temperature Test ---

                             

                            Temperature Test Passed!!!

                             

                            Temperature = 53 degrees C below maximum.

                             

                             

                            --- Reading Brand String ---

                             

                            Detected Brand String:

                            Intel Core i7-2600K   3.40GHz

                             

                             

                            Brand String Test Passed!!!

                             

                             

                            --- Reading CPU Frequency ---

                             

                             

                            Expected CPU Frequency is --> 3.40

                             

                            Detected CPU Frequency is --> 5.06123

                             

                             

                            CPU Frequency Test Passed!!!

                             

                             

                            Expected frequency - The highest frequency at which the tested processor was manufactured to operate

                            Detected frequency - The frequency at which the tested processor is currently operating

                            Power management modes can create marginally higher or lower detected frequency

                            than expected frequency. Small variations in clock frequencies are common.

                             

                             

                            --- FSB NOT Supported on this Processor ---

                             

                            --- Running Base Clock test ---

                             

                            Detected Base Clock --> 101

                            Base Clock test Pass ---

                            ..QPI rate Test not supported..

                            ..Skipping QPI rate Test..

                             

                             

                            Skipping QPI rate Test

                             

                            --- Running Floating Point test ---

                             

                            Million Floating Points per Second, MFLOPS --> 432

                            Floating Point Test Pass ---

                             

                            --- Running Prime Number Generation Test ---

                             

                            Operation Per Second--> 4.65205e+006

                            Prime Number Generation Test Pass ---

                             

                            --- Reading Cache Size --- 

                             

                            - Detected L1 Data Cache Size --> 4 x 32

                            - Detected L1 Inst Cache Size --> 4 x 32

                             

                            - Detected L2 Cache Size --> 1024

                            - Detected L3 Cache Size --> 8192

                             

                             

                            Cache Size Test Passed!!!

                             

                            --- Determining MMX - SSE capabilities ---

                             

                            --- CPU FEATURES DETECTION FOR ---

                                         ---        MMX SSE       ---

                            MMX - MMX Supported --> Yes

                            SSE - SSE Supported --> Yes

                            SSE2 - SSE2 Supported --> Yes

                            SSE3 - SSE3 Supported --> Yes

                            SSSE3 - SSSE3 Supported --> Yes

                            SSE4.1 - SSE4.1 Supported --> Yes

                            SSE4.2 - SSE4.2 Supported --> Yes

                              --- MMX SSE - capabilities check complete ---

                             

                            MMX Test Result --- PASS

                            SSE Test Result --- PASS

                            SSE2 Test Result --- PASS

                            SSE3 Test Result --- PASS

                            SSSE3 Test Result --- PASS

                            SSE4.1 Test Result --- PASS

                            SSE4.2 Test Result --- PASS

                            MMX SSE Testing Passed !!

                             

                            --- Determining AVX AES PCLMULQDQ capabilities ---

                             

                             

                            --- CPU FEATURES DETECTION FOR ---

                                        --- AVX/AES/PCLMULQDQ ---

                            AVX - Advanced Vector Extensions Supported --> Yes

                            AVX OS Support   - AVX Operating System Supported --> Yes

                            AES - Advanced Encryption Standard Supported --> Yes

                            PCLMULQDQ - Polys Carry-Less Multiply Supported --> Yes

                              --- AVX AES PCLMULQDQ capabilities check complete ---

                             

                            AVX Compare Test Result --- PASS

                            AES Test Result --- PASS

                            PCLMULQDQ Test Result --- PASS

                            AVX AES PCLMULQDQ Testing Passed !!

                             

                            --- Reading Memory Size ---

                             

                             

                            Detected Memory Size is --> 24.00GB

                             

                             

                            --- Integrated Memory Controller Stress Test ---

                             

                            --- Integrated Memory Controller Stress Test Pass!!! ---

                             

                            Integrated Memory Controller Test Pass!!!

                             

                            Chipset          : Intel(R) 6 Series Chipset or Intel(R) C200 Series Chipset

                            Chipset Stepping : B3

                             

                             

                            1 device connected to PCI Express Port 1

                               1 : Стандартный мост PCI - PCI

                             

                             

                            1 device connected to PCI Express Port 4

                               1 : Renesas Electronics USB 3.0 Host Controller

                             

                             

                            1 device connected to PCI Express Port 5

                               1 : VIA 1394 OHCI-совместимый хост-контроллер

                             

                             

                            3 device connected to SATA Controller 1

                               1 : Corsair Force GT ATA Device

                               2 : Samsung SSD 840 EVO 250GB ATA Device

                               3 : WDC WD7501AALS-00J7B0 ATA Device

                             

                             

                            5USB devices detected

                               1 : RME Babyface

                               2 : USB-устройство ввода

                               3 : Составное USB устройство

                               4 : iLok

                               5 : TP-LINK Wireless USB Adapter

                             

                             

                            2 device connected to Intel High Definition Audio Controller

                               1 : Устройство с поддержкой High Definition Audio

                               2 : Устройство с поддержкой High Definition Audio

                             

                             

                            PCH LAN Device 'Ethernet-контроллер' detected

                             

                             

                            --- Platform Controller Hub Test Completed!!! ---

                             

                             

                            --- Querying for Intel(R) Integrated Graphics Device (IGD) ---

                             

                             

                            ..Detected 8086 as Vendor ID on Device 2 on Intel(R) processor..

                            ..Intel(R) Integrated Graphics Device Presence Detection Passed..

                             

                            ..2D Graphics Visual Display Passed..

                             

                            ..Graphics Visual Display Passed..

                             

                            ..Rotating Display Passed..

                             

                            --- CPU Load ---

                             

                            --- Load Level = 8

                             

                            CPU Load Passed!!!

                             

                            --- Temperature Test ---

                             

                             

                            Temperature Test Passed!!!

                             

                             

                            Temperature = 39 degrees C below maximum.

                             

                            --- Test End Time: 01/21/2016 09:52:00---

                             

                             

                             

                            CPU-Z shows the same clock speed jumps as before.

                             

                            Thank you,

                            Evgeny

                            • 11. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                              ivanu_intel

                              I have checked the result for the test and I can see the processor is over clocked, you can find out about it when you check the Expected CPU Frequency is --> 3.40 but the Detected CPU Frequency is --> 5.06123.

                               

                              That’s out of the processor specifications and at that frequency any issue can be expected, you can over clock a processor and it can work fine for a well but at some point it will fail, I strong recommend running this processor under the processor specifications and use the RAM at 1066 MHz or 1333 MHz and at 1.5V which is the recommended frequency for this processor.

                               

                              You can see the processor specifications here:

                              Intel® Core™ i7-2600K Processor (8M Cache, up to 3.80 GHz) Specifications

                               

                              If you are interested in over clocking your system please check this website for better assistance.

                              http://www.overclock.net/

                              NOTE: This link is being offered for your convenience and should not be viewed as an endorsement by Intel of the content, products, or services offered there.

                               

                              Warning: Altering clock frequency and/or voltage may: reduce system stability and useful life of the system, processor, and other system components; (ii) cause the processor and other system components to fail; (iii) cause reductions in system performance; (iv) cause additional heat or other damage; and (v) affect system data integrity. Intel has not tested, and does not warranty, the operation of the processor beyond its specifications. Intel has not tested, and does not warranty, the operation of other system components beyond their industry standard specifications. Intel assumes no responsibility that the processor and other system components, including if used with altered clock frequencies and/or voltages, will be fit for any particular purpose.

                              • 12. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                                soundroad

                                Hi Ivan,

                                 

                                thank you very much for your answers!

                                 

                                I should mention that I did not any overclocking and usually don't plan to do it!

                                 

                                I did this test after I've set BIOS settings by default. Now I checked BIOS once more and I found the warning message on "Performance" page. I mean there are no settings shown, only the warning about unsupported processor speed or something like this. This message appears on "Performance" page if I try to set BIOS default settings. Do you have any suggestions?


                                Thank you,

                                Evgeny

                                • 13. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                                  ivanu_intel

                                  You will need to make sure that the RAM is running at 1066 MHz or 1333 MHz and at 1.5V; you should be able to check on that under performance in the BIOS, you will see there the memory configuration. You will see the memory voltage and if the RAM has XMP (Extreme Memory Profile) disable the XMP.

                                  • 14. Re: I7-2600K speed drops to 1600MHz on DZ68DB when running Prime95
                                    soundroad

                                    Hi Ivan,

                                    I checked BIOS: RAM speed - 1333, voltage - 1.5 v. But(!) I have four modules installed (2x2 in dual channel mode) and they are different. 2 of them support XMP and 2 others not. Could it be a reason?

                                     

                                    Here is a sample from CPU-Z repost:

                                     

                                    DIMM #1
                                    SMBus address0x50
                                    Memory typeDDR3
                                    Module formatUDIMM
                                    Manufacturer (ID)Samsung (CE000000000000000000)
                                    Size4096 MBytes
                                    Max bandwidthPC3-10700 (667 MHz)
                                    Part numberM378B5273CH0-CH9 
                                    Serial number004FDF9F
                                    Manufacturing dateWeek 02/Year 12
                                    Number of banks8
                                    Nominal Voltage1.50 Volts
                                    EPPno
                                    XMPno
                                    AMPno
                                    JEDEC timings tableCL-tRCD-tRP-tRAS-tRC @ frequency
                                    JEDEC #16.0-6-6-17-23 @ 457 MHz
                                    JEDEC #27.0-7-7-20-27 @ 533 MHz
                                    JEDEC #38.0-8-8-22-30 @ 609 MHz
                                    JEDEC #49.0-9-9-24-33 @ 666 MHz

                                     

                                     

                                    DIMM #2
                                    SMBus address0x51
                                    Memory typeDDR3
                                    Module formatUDIMM
                                    Manufacturer (ID)Crucial Technology (7F7F7F7F7F9B00000000)
                                    Size8192 MBytes
                                    Max bandwidthPC3-12800H (800 MHz)
                                    Part numberBLS8G3D1609DS1S00.
                                    Serial numberA5057B22
                                    Number of banks8
                                    Nominal Voltage1.50 Volts
                                    EPPno
                                    XMPyes
                                    XMP revision1.3
                                    AMPno
                                    JEDEC timings tableCL-tRCD-tRP-tRAS-tRC @ frequency
                                    JEDEC #15.0-5-5-14-22 @ 444 MHz
                                    JEDEC #26.0-6-6-16-26 @ 533 MHz
                                    JEDEC #37.0-7-7-19-31 @ 622 MHz
                                    JEDEC #48.0-8-8-22-35 @ 711 MHz
                                    JEDEC #59.0-9-9-24-39 @ 800 MHz
                                    JEDEC #610.0-9-9-24-39 @ 800 MHz
                                    JEDEC #711.0-9-9-24-39 @ 800 MHz
                                    XMP profileXMP-1600
                                    SpecificationPC3-12800H
                                    Voltage level1.500 Volts
                                    Min Cycle time1.250 ns (800 MHz)
                                    Max CL9.0
                                    Min tRP11.25 ns
                                    Min tRCD11.25 ns
                                    Min tWR15.00 ns
                                    Min tRAS30.00 ns
                                    Min tRC46.25 ns
                                    Min tRFC300.00 ns
                                    Min tRTP7.50 ns
                                    Min tRRD6.00 ns
                                    Command Rate2T
                                    XMP timings tableCL-tRCD-tRP-tRAS-tRC-CR @ frequency (voltage)
                                    XMP #15.0-5-5-14-21-2T @ 444 MHz (1.500 Volts)
                                    XMP #26.0-6-6-16-25-2T @ 533 MHz (1.500 Volts)
                                    XMP #37.0-7-7-19-29-2T @ 622 MHz (1.500 Volts)
                                    XMP #48.0-8-8-22-33-2T @ 711 MHz (1.500 Volts)
                                    XMP #59.0-9-9-24-37-2T @ 800 MHz (1.500 Volts)
                                    XMP #610.0-9-9-24-37-2T @ 800 MHz (1.500 Volts)
                                    XMP #711.0-9-9-24-37-2T @ 800 MHz (1.500 Volts)
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