9 Replies Latest reply on Dec 28, 2015 10:35 AM by techguy

    AMD FX-8350 4 cores don't work

    401e

      Hello. I have AMD FX-8350 Eight-Core (Vishera) cpu, my motherboard is asus m5a99x evo r2.0. Both Aida64 and CoreTemp show that only #0,2,4,6 cores are loaded while #1,3,5,7's load are from 0% to 4% or so. FPS in games(BF4, withcer 3) suffers a lot from this. It happens not only in games but always. 4 cores are loaded up to 99% and the other 4s keep resting. I've tried resetting bios to the default settings but that didn't work. No over-clocking had been done.
      OS: Windows 7 Ultimate 64-bit.

      RAM: G Skill RipjawsX F3-17000CL9-4GBXM x4.
      GPU: AMD HD-7950

        • Re: AMD FX-8350 4 cores don't work
          techguy

          Due to the way AMD CPUs process data and how well or poorly applications are written, you will always have the second core of a dual core module that runs with less load than the primary core of a dual module. In addition Windows does a very poor job of feeding AMD FX and other model AMD CPUs. The link below from Microsoft can offer a small improvement in Win 7 performance. Read the Windows patch details so that you understand what changes are being made to your system before you use any patch.

           

          https://support.microsoft.com/en-us/kb/2645594

           

          Microsoft also lists a second "hot fix" for the core parking issue under the link below - which can NOT be uninstalled - according to Microsoft. In addition hot fix #2646060 should only be installed AFTER hot fix # 2645594 is installed. Note that the # 2646060 hot fix may prevent the PC going into the C6 sleep mode, which is of little concern to many PC users.

           

          https://support.microsoft.com/en-us/kb/2646060

          1 of 1 people found this helpful
          • Re: AMD FX-8350 4 cores don't work
            Earnhardt

            You are running the latest bios "Version 2501 " ?

             

            I built a system earlier this year with the FX 8350 and Crosshair formula z mobo (Windows 7 64) and never had any issues as you describe.

             

            It ran like a dream with a Matrix 7970.I would do a little more testing before I installed any hotfix, especially if its not reversible.

            1 of 1 people found this helpful
              • Re: AMD FX-8350 4 cores don't work
                techguy

                FWIW- The Windows hot fixes have been verified to be just fine by many Windows 7 FX users over the past three years. The first one #2645594 is removable. It addresses the CPU core scheduling and core parking problem. The second hot fix #2646060 is not removable. It alters the standby C6 process so that the core parking process is not compromised. This is all explained in the overview of each hot fix. Win 8 was suppose to offer another ~10% improvement for FX users (from better CPU core scheduling), but many do not care for Win 8 vs. Win 7.

                 

                The OP's system certainly sounds like it is suffering from core parking but there could be numerous issues. The hot fixes don't make huge performance gains but every little bit helps. Obviously if half the cores are only seeing ~4% load then something is wrong.

                  • Re: AMD FX-8350 4 cores don't work
                    grumpy

                    I have exactly the same cpu on ASRock 990FX Extreeme3 motherboard with Crucial 4GB DDR3 Ballistix Tactical UDIMM 240 pin 1866 MHz cl9 1,5v dual channel (4+4 gb) and gigabyte r7 260x GDDR5 graphics. I haven´t had any problems with my hardware - non. I used windows 7 first then changed it for free windows 10( windows is on 450/450 120gb SSD). Under windows 10 i got a bleasant surprise - memory clock had rosen up a level to 2166MHz at 1,5v. AMD 8350 should not support that speed nor should ASRock 990FX Extreeme3, even my graphics work at 1188MHz as if it is overclocked. I prohibited overclocking in bios earlier. Only lag is my graphics. i´l use crossfire with existing Gpu*2. Midrange computer builders follow my dust.

                      • Re: AMD FX-8350 4 cores don't work
                        techguy

                        Every FX-8350 that I have seen will run 2133 MHz. rated DDR3 RAM without issue. The official supported frequency may be lower but most top quality RAM rated for 2133 MHz. seems to work fine. Higher frequency RAM has even been  supported on some systems. Asrock has good Extreme series mobos and BIOS in my experience. No problem here running FX-8350 @ 4.7 GHz. 24/7 for several years without any issues on Fatality Pro mobo with Mushkin and/or G.Skill RAM running at 2133 MHz @ 1.5v. I also have the Windows 7 hot fix # 2645594 installed.

                          • Re: AMD FX-8350 4 cores don't work
                            grumpy

                            My numbers got mixed up. RAMs are working @ 2133MHz as brighter understood already. I bought them as 1866MHz (14900) each from different store (estonia is a very tiny country with very tiny shops), i was afraid that 2133MHz rams would not work. I have been complitely satisfied with new systems speed so i have not overclocked anything. Not under win 7 (rams @ 1866MHz, 1,5v) and not under win 10 (same rams @ 2133MHz, 1,5v). So as wise men in estonia say AMD is our reliquary.

                              • Re: AMD FX-8350 4 cores don't work
                                techguy

                                It's possible that Win10 is testing the RAM and other hardware to see what the highest stable frequency is and then running the hardware accordingly? Usually a good BIOS will test the RAM and adjust but I haven't heard of this automatically happening with graphics. As long as it's all stable. enjoy.

                      • Re: AMD FX-8350 4 cores don't work
                        401e

                        I've tried updating bios version, updating drivers and chipset and installing windows hotfixz. Now fps has grown like 20-40% depends on the game and all 8 cores are loaded on 100% with aida 64 while stressing cpu. Tbh updating bios didnt do much so i guess the problem was in windows. However thank you all very much