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I have a laptop with a core2duo CPU. When I am setting up my Ubuntu VM, should I set it to have 2 cores or 1? Do you always set it to the number of cores your host has?

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tl;dr: It doesn't matter, so use one core.

Full version: If you're talking about the number of cores the virtual machine has, the number of cores the host has doesn't really matter, with some important caveats"

  • If you set up a huge number of cores (whether multiple cores on multiple VMs or multiple single-core VMs) then you'll end up oversubscribing the CPU of the host machine, and you'll see a performance drop.

Unless you have a reason to set the VM to multiple cores, set it to 1.

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