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I have Ubuntu installed as VM on my laptop. My laptop has quad core with HT technology making it 8 cores.

Within Ubuntu VM I can only use max of 4 cores.

What should I do so I can access all 8?

Which Linux distribution would let me use all my cores? Which VM software should I use?

Any advices?

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"HP" Technology? Maybe you mean Hyper Threading? – psusi Nov 17 '12 at 22:37
@psusi, you're absolutely correct. – HelpNeeder Nov 17 '12 at 22:44
Well, I don't think Ubuntu has such limitation; in VirtualBox I successfully gave 8 cores to a VM. Do you see the 8 cores on the host OS? – Renan Nov 17 '12 at 22:50
@Renan, yes, task manages within Windows 8 as my host shows 8 cores. In VMWare System monitor shows 4 cores. When in settings I try to add more than 4 cores it tells me "The virtual machine is configured to run with 6 CPUs, but VMware Player supports only up to 4 CPUs.". So virtual box doesn't have such problem? – HelpNeeder Nov 17 '12 at 22:59
up vote 2 down vote accepted

You are hitting a VMware Player limitation.

VMware Player takes advantage of the latest hardware to create virtual machines with up to 4 virtual processors, 2 TB virtual disks and up to 64 GB of memory per virtual machines.

VirtualBox has a much higher limit (32, as far as I can tell).

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