HOWTO: Get Windows 7 to detect your new multi-core processor

Anonymous
2009-12-15T11:11:06+00:00

There is a very rare instance that may happen under Windows 7 if you upgrade

your processor from a single to a dual or a dual to a tri or a tri to quad core processor. Under Windows Task manager > Performance tab you may encounter only the previous amount of cores visible even if you have Task Manager > View > CPU history > One Graph per CPU checked off.

This graph pane area which should show the equivalent amount of cores per graph is directly tied into the MSConfig > Boot tab > Advanced options > "Number of Processors" setting. You may not show the correct amount of cores in this MSConfig pull-down.

Let me give an example:

You install Windows 7 with a dual-core processor and have this option checked for "Number of Processors" (in Msconfig > Boot > Advanced options) and the amount set to "2" (for dual core). This setting is not mandatory to be set but some ppl do in order to force Task Manager to show 2 graphs (or 3). One graph for each processor. At a later point in time you upgrade to a Quad-core or Tri-Core processor. The OS will not read this extra core or have anything enabled to physically use this extra core(s) until the following are performed:

  1. Uncheck in MSConfig > Boot tab > Advanced Options > "Number of Processors" and exit MSConfig
  2. d/l and install an applet called EasyBCD 1.7.2 (or later, Google: EasyBCD) which supports many features of Windows 7.
  3. Go into Advanced Options in EasyBCD and select "Limit Widows to '0' CPUs (Leave 0 to reset)". Click "Apply Settings" and exit EasyBCD.

NOTE: This will force the OS to reset the count to default for the amount of Cores you now have. There is possibly a boot setting that can be added that I may not be aware of to do this same function but this little applet works and does the same thing. Don't muck around with any other setting in this utility if you don't know what you are doing it may leave your computer unbootable and a complete reinstall or long repair may need to be performed. Just make sure this one setting is set to "0"

  1. Completely shutdown the OS (not reboot or restart or logout). Correctly Shutdown you computer so the it powers down.
  2. upon restart into the OS the Task Manager > Performance tab should now show the correct amount of per core graphs if you have the "One Graph per CPU" option selected. Yay your back in business =)

Notes: Some of these discrepancies will appear if your OS is reading the incorrect amount of cores.

  1. Device Manager will show the correct amount of Cores for the PC after the new CPU is installed even tho Task Manager still shows the old amount of cores. This is why you need to preform these steps above to fix this disparity and enable the OS to work with the new additional core.
  2. CPU-Z (Google: CPUID CPU-Z) will show an incorrect amount of cores until you preform the above steps.
  3. SiSoft Sandra (Google: SiSoft Sandra) will show the correct amount of Cores for the PC after the new CPU is installed even tho Task Manager still shows the old amount of cores. This is why you need to preform these steps above to fix this disparity and enable the OS to work with the new additional core.
  4. Reinstalling Windows 7 with the "Upgrade" (not Custom Option) will not fix this issue until the above steps are performed. The reinstall should clear the "Number of Processors" setting in MSConfig but it doesn't! Hence the need to run the above steps and avoid a reinstall which takes greatly more time and still does not fix this issue.
  5. In a dual boot (XP/Win7) PC, the XP Task Manager will show the correct amount of Cores in Task Manager > Performance tab even tho the same place under Windows 7 will not! Hence the need to perform the above steps.

This is a rare issue, but if you are upgrading CPUs in the future these are a very important steps to enable your Win7 OS to take advantage of this extra core you are buying. Even tho in places like Device Manager it will show the correct amount of cores the MSConfig setting will override the Device Manager only allow you to work with a lessor amount of cores thereby limiting your CPUs true potential preserving your good investment.

Good Luck! I hope someone who encounters this issue finds their way here after a CPU upgrade or they may rip their hair out and I can tell you from experience I was making the Level 3 tech support at Microsoft rip their hair out when I found this issue lol

I was getting an Experience Index value for Processor of 6.3 when this core was disabled and not showing up in Task Manager > Performance tab. Once the above steps were performed my Performance Index jumped to 6.9! My old Dual-Core CPU was an Experience Index of 6.1 to show you the difference a 3rd core can add to your system. In the future, once I start gently Overclocking my new Triple-core processor (once I get a better CPU cooler) It should exceed 7.2-7.4 or greater Experience Index. =)

TCsenter wrote also:

Some recommendations (make sure you are running as Administrator):

  • Run MSConfig -> Change to Boot tab -> Advanced Options -> "Number of Processors", make sure there is no check mark.
  • Delete processor entries listed in Device Manager, then reboot and allow Windows to redetect/reinstall them.
  • In BIOS, check for an option named Max CPU ID Value or CPU ID Max Val and make sure its set to disabled .  This option is only provided for OS prior to Windows 2000.  Save and Exit BIOS.
  • Check for a BIOS update for your system or motherboard.
  • Confirm the CPU model is supported by the motherboard
Windows for home | Previous Windows versions | Devices and drivers

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  1. Anonymous
    2010-05-12T12:02:40+00:00

    Hello...

    I am having an issue very similar to others here... I will break it down in detail, yet brief...

    PC System Specs:

    Machine: IBM Intellistation Z-Pro 6223 with 2 x Intel 3.6Ghz Duo Core Processors (2 Physical Processors = 4 cores)

    Win OS: Windows 7 Home Premium 64-Bit

    Device Manager:

    Computer: Advanced Configuration and Power Interface (ACPI) PC

    Processors: 4 x Intel(R) Xeon(TM) CPU 3.60 Ghz

    Here is my dilema...

    I have the *IDENTICAL* machine sitting next to this one. Same procs, video card, etc., running Windows XP Pro.  It shows four (4) processors in Device Manager, AS WELL AS (4) processors in Task Manager.

    My Windows 7 Machine shows four (4) processors in Device Manager, BUT ONLY two (2) processors in Task Manager.

    I have tried *every step* of your suggestions here, and nothing gets them working as they should.  Does anyone have any idea where I can get Windows 7 to utilize all the processors!?

     

    I also have another machine sitting next to this one.  Z-Pro 6221 which does the exact same thing.  I have installed 32-Bit Windows 7 to see if that makes a difference, but it does not.

    If your 90 day technical support for the OS has not ran out I would contact Microsoft ASAP to get them involved in this. I know they only offer a pitiful 90 days of technical support for their bullsh it OS but contact them and make it known about this thread and solution. I am at a loss as to what can be done to fix this. I know that completely wiping and reinstalling the OS will not fix this problem. I have tested this myself and its in the way the HAL layer arranges itself that is the core problem here.

    You have to basically force the HAL to show the correct amount of processors in the task manager with my steps. The MSConfig > Boot tab > Advanced Options is what taps into the HAL to set these settings along with EasyBCD utility. The HAL is bugged in how it interprets the number of processors especially if you upgrade your cores from a lower value to a higher value. But who knows maybe in your particular case a clean full OS install (with your important data backed up to a SkyDrive for instance) can possibly fix this situation.

    I would go ahead and do that in your case. Backup all the valuable data you need and wipe the drive clean and reinstall the OS and reimport you data from the backup. I know its a tediously aggravating process but I am at a loss as to what to tell you to be honest.

    You have a system I can not begin to even troubleshoot as you have 2 physical processors on your Mobo. I only have a single multi-core one (as do the other posters). The steps you need to overcome your particular problem may be very different then a single core users would be.

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  2. Anonymous
    2010-05-07T03:56:54+00:00

    Hello...

    I am having an issue very similar to others here... I will break it down in detail, yet brief...

    PC System Specs:

    Machine: IBM Intellistation Z-Pro 6223 with 2 x Intel 3.6Ghz Duo Core Processors (2 Physical Processors = 4 cores)

    Win OS: Windows 7 Home Premium 64-Bit

    Device Manager:

    Computer: Advanced Configuration and Power Interface (ACPI) PC

    Processors: 4 x Intel(R) Xeon(TM) CPU 3.60 Ghz

    Here is my dilema...

    I have the *IDENTICAL* machine sitting next to this one. Same procs, video card, etc., running Windows XP Pro.  It shows four (4) processors in Device Manager, AS WELL AS (4) processors in Task Manager.

    My Windows 7 Machine shows four (4) processors in Device Manager, BUT ONLY two (2) processors in Task Manager.

    I have tried *every step* of your suggestions here, and nothing gets them working as they should.  Does anyone have any idea where I can get Windows 7 to utilize all the processors!?

    I also have another machine sitting next to this one.  Z-Pro 6221 which does the exact same thing.  I have installed 32-Bit Windows 7 to see if that makes a difference, but it does not.

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  3. Anonymous
    2010-05-03T18:06:32+00:00

    thank you very much for this! I just upgraded from a Pentium D 930 to a C2Q Q6600 and this solved my issue. Thanks!

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  4. Anonymous
    2010-04-27T22:48:24+00:00

    passionfly,

    I meant to say that my mother board has two physical sockets.  Each socket has a dual core AMD Opteron processor.  In device manager, under processors, it shows:

    Dual-Core AMD Opteron Processor

    Dual-Core AMD Opteron Processor

    Dual-Core AMD Opteron Processor

    Dual-Core AMD Opteron Processor

    However, in Task Manager the CPU Usuage History only shows two boxes with CPU usuage.

    The main recording program I use, has a GUI that shows the real time CPU usuage of each core.  (If you have a quad core, 4 separate bars appear). 

    As of now the program shows only 2 bars when it should be 4.

    Keep in mind that I used to use XP64 pro and both the computer and Cakewalk Sonar showed me all 4 CPU usuage meters.

    Any help is appreciated.

    I'm guessing that everybody on this forum is not in th situation I'm in whereas their motherboard has two physical sockets.   Remember, they're showing up in Device manager just not in Task manager.  I've done all of the things you've suggested and it's still the same.  I know the motherboard has no issues because it worked as a quad core with XP64pro.  I've confirmed with a few different people that Windows 7 Home Premium will not support my configuration.  Any help is much appreciated.

    k, I understand. Since I only have one physical processor socket this guide will work for likewise one processor socket motherboards. Since you have 2 and I completely neglected to include any mention of this I apologize for my mistake and subsequent posts on that topic. I am not 100% positive for the steps necessary to make a double socketed motherboard work since I have no motherboard like this to test it out on.

    The one part that I know should work above to get your dual sockets to default status is step 1) Uncheck in MSConfig > Boot tab > Advanced Options > "Number of Processors" and exit MSConfig The other steps are there to forcefully inject the correct core quantities into the OS (registry) substrings via the freeware tool you can download (EasyBCD). Its this part that may fail so you may have to try a different route to assign the correct core total to show up in Task Manager.

    Regardless of the amount of physical processor sockets your Mobo has and is correctly being detected by Device Manager, the Task Manager MUST show them correctly or the OS will never take advantage of the true total (hence why I wrote this fix). I would strongly suggest you contact Microsoft Tech Support and tell them you found a very nasty bug in regards to your issue and also refer them to this link that deals with a single processor socket Mobo and not a dual. Their level 3 support engineers should get you a workaround to fix this weird bug.

    I'm pretty sure I could fix this problem for you had I a dual socket (and 2 processors) Mobo to test with, but I don't =(

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  5. Anonymous
    2010-04-26T14:13:33+00:00

    passionfly,

    I meant to say that my mother board has two physical sockets.  Each socket has a dual core AMD Opteron processor.  In device manager, under processors, it shows:

    Dual-Core AMD Opteron Processor

    Dual-Core AMD Opteron Processor

    Dual-Core AMD Opteron Processor

    Dual-Core AMD Opteron Processor

    However, in Task Manager the CPU Usuage History only shows two boxes with CPU usuage.

    The main recording program I use, has a GUI that shows the real time CPU usuage of each core.  (If you have a quad core, 4 separate bars appear). 

    As of now the program shows only 2 bars when it should be 4.

    Keep in mind that I used to use XP64 pro and both the computer and Cakewalk Sonar showed me all 4 CPU usuage meters.

    Any help is appreciated.

    I'm guessing that everybody on this forum is not in th situation I'm in whereas their motherboard has two physical sockets.   Remember, they're showing up in Device manager just not in Task manager.  I've done all of the things you've suggested and it's still the same.  I know the motherboard has no issues because it worked as a quad core with XP64pro.  I've confirmed with a few different people that Windows 7 Home Premium will not support my configuration.  Any help is much appreciated.

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