I have a multicore CPU with Windows 10 and I would like to test a Software running as if my PC was a singlecore CPU.

Is there any way to limit Windows 10 installed in a multicore CPU (Quad Core) to work as a singlecore?

  • 1
    use msconfig and allow only 1 core. – magicandre1981 Jun 23 '17 at 15:04

Some PCs (motherboards) allow you to control how many cores are active. This method requires you to shut down the PC and boot into BIOS. If you set your machine to 1 core, then it will be slow overall until you are done with your testing, shut down, and boot into BIOS again to revert the setting.

  • I don't think that is a good idea as it will affect the whole system. – jitendragarg Jun 22 '17 at 15:25
  • Thanks for the answer regarding affinity; it's a more useful tool than my old-school answer. – Christopher Hostage Jun 22 '17 at 15:28
  • Always happy to help. Even I stumbled up on it doing random walkthrough of task manager. It is not really advertised feature, for good reason too. – jitendragarg Jun 22 '17 at 15:31
  • Thanks!!! This is what I was looking for! I just set this value in the BIOS and it worked!! – RogerR Jun 23 '17 at 7:05

In older version of Windows, you can run the application, then go to task manager, right click the process and set affinity. In the resulting popup, you can choose which and how many cores to use.

In case of Windows 10, you will have to right click on process, select "Go to details" and then again, select "Set affinity".

Edit: You can follow the steps for Windows 10 here. Do let me know if there is a better way to share a zip file.


  • This isn't quite the same as running really single-core. The software will detect multiple cores, but the OS will only run it on 1 of the cores. This may be all the poster wants, or isn't fit for purpose at all. It highly depends on what the software is trying to do. – Tonny Jun 22 '17 at 15:30
  • It does simulate single core for specific application. The application will detect one core, if I am correct. Although I guess I should write a quick program to test it. – jitendragarg Jun 22 '17 at 15:32
  • Whether or not it detects a single core or not will depend on which system-call(s) is used for the detection. – Tonny Jun 22 '17 at 16:34
  • Thanks for the response, it also worked! But I wanted the overall system to work as a single core CPU – RogerR Jun 23 '17 at 7:05
  • Oh good. In that case, Christopher's answer works perfectly. Although, do remember to change the settings after testing is completed. :) – jitendragarg Jun 23 '17 at 16:55

VirtualBox (both Free and free) is a great virtualization package, adn you can control how many cores/cpus each VM has available to it. You can also control how much RAM, disk space, etc. each VM has.

Note however that you'll need to install the OS from "bare metal", possibly deal with licensing of said OS, etc.

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