VMware Fusion, CPU cores confusion?

Discussion in 'Windows, Linux & Others on the Mac' started by MBX, Apr 12, 2010.

  1. MBX macrumors 68000

    Sep 14, 2006
    Hey i've got a mac pro with 2x 3ghz Core Duo Xeon's, yet Vmware Fusion (latest version and latest 3.1 beta) tells me it has only 2 cores and therefore can't really use 4 cores.

    When i use 2 cores in VMware settings and then launch activity monitor i can see that it seems to use all 4 cores anyway.

    Any idea what's going on?
  2. Zortrium macrumors 6502

    Jun 23, 2003
    The number of cores you allocate in VMware Fusion doesn't directly correlate to physical cores -- to the virtual machine, Fusion presents the given number of "virtual" CPUs, but the instructions that the virtual machine passes to those CPUs may be executed on any of your machine's physical CPUs. The number of virtual CPUs given is just an abstraction; there's nothing preventing Fusion from, for example, telling Windows that it's got 16 cores even if your machine only has 4, though this wouldn't given any performance benefit because all 16 sets of instructions would have to be run on only the 4 available real cores.
  3. Haruhi macrumors regular

    Sep 19, 2008

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