Quad core with hyper threading --- 4 processors or 8?

Discussion in 'Installation and Configuration of Parallels Desktop' started by Parallels User, Mar 6, 2018.

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  1. Parallels User

    Parallels User Guest

    I am running a 2015 MacBookPro with an I7 quad core. When I assign processors in the configuration panel for a VM are those numbers in cores or threads? In other words, when I enter 2 for processors is that 1 core hyper threaded so it looks like 2 processors or is it 2 cores?
     
    Parallels User, Mar 6, 2018
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  2. PieterW1

    PieterW1 Bit poster

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    It seems to be that 2 processors only means two threads. When I select number of processors to be 2 for both a Windows 10 and Ubuntu 16.4, then both VMs only show 2 processors. In windows you see this by going to the task manager and selecting "CPU" and in Ubuntu use "lscpu" in the terminal and look at "Thread(s) per core".

    It looks like parallels is not giving all of the processor to the VM. This is in Parallels Version 13.3.2 (43368).
     
    PieterW1, Jul 19, 2018
    #2
  3. PaulChristopher@Parallels

    PaulChristopher@Parallels Product Expert Staff Member

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    Hi @SterlingG, It's in terms of Core's not thread. Parallels Desktop have Adaptive Hypervisor technology helps you to distribute your Mac CPU resources between the OS X (primary or host OS) and the guest OS (your virtual machine) in the most efficient way.
    Please pay attention when exceeding the recommended RAM value - your overall Mac performance may be significantly decreased (even down to computer freeze). In Parallels Desktop Pro Edition, we have a feature to extend memory unit. (Configuration -> Hardware -> CPU & Memory -> Advanced Settings -> Extended memory unit)
     
    PaulChristopher@Parallels, Jul 26, 2018
    #3
  4. PaulChristopher@Parallels

    PaulChristopher@Parallels Product Expert Staff Member

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    Hi @PieterW1, yes, we do have that feature! In Parallels Desktop Pro Edition, we have a feature to extend memory unit. (Configuration -> Hardware -> CPU & Memory -> Advanced Settings -> Extended memory unit). You can assign the maximum level however it decreases Mac's performances.
     
    PaulChristopher@Parallels, Jul 26, 2018
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  5. PieterW1

    PieterW1 Bit poster

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    Hi @PaulChris@Parallels,
    I understand that Parallels Home has a 2 "Processor" limit, and Professional has a much higher limit.

    But the meaning of "Processor" is not clear. The most widely used terms for Processor, CPU and Thread in terms of hardware seem to be:
    Processor: The physical chip on your board.
    CPU or Core: An instance of a Processing Unit.
    Thread: A computational unit with most of the functionality of a CPU.

    So, a PC with a single quad core i7 would be: 1x Processor; 4x CPUs/Cores; 8x Threads.

    Given this definition (I understand that it is not universal, but does seem to be the most widely used - again see Linux iscpu command) it seems that the word "Processors" in the Parallels configuration option should maybe be renamed to CPUs or Cores? As it currently stands, it gives the impression that you are giving a complete core/processing unit to the host where in fact you are only giving it a thread.

    Regards,
    Pieter
     
    PieterW1, Jul 26, 2018
    #5
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