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I am using Ubuntu 22 and Mathematica 13. According to the description of my laptop I should have four CPU cores, as seen in the following screenshot:

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However, Mathematica only seems to recognize two kernels when attempting any parallel computation (see the following screenshot).

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Am I seeing something wrong, or is there a way to tell Mathematica to use all four kernels?

Many thanks!

Philipp Strasberg
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    You have two physical cores - and four logical "cores" because of hyperthreading. Read here: https://support.wolfram.com/27877?src=mathematica "By design, Mathematica automatically launches subkernels equal to the number of physical CPU cores." – flinty Jan 25 '23 at 22:30
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    It also says: "To override this setting, use the LaunchKernels[n] function, where n is an integer indicating the number of local subkernels to launch." – flinty Jan 25 '23 at 22:31
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    And here is your CPU specs which indeed show only 2 physical cores: https://www.intel.com/content/www/us/en/products/sku/88193/intel-core-i56200u-processor-3m-cache-up-to-2-80-ghz/specifications.html. Note that Intel likes advertising HyperThreading as doubling the number of cores, but security paranoid folks (e.g. OpenBSD) recommend to disable it to protect from side-channel attacks. – Victor K. Jan 25 '23 at 22:35
  • Since when having a support ticket answering a question is reason to close it? This could be consider a duplicate of this but I don't see how the Wolfram Support argument holds – rhermans Jan 26 '23 at 09:13

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