Parallels does not trigger Turbo Boost on a Mac Book Pro

Discussion in 'Windows Guest OS Discussion' started by mdz, Jul 5, 2018.

  1. mdz

    mdz Bit Poster

    Messages:
    9
    I tried a simple google search and comes out nothing so I guess few have noticed about this potential issue that may make our VM perform slower than it could be.


    On modern Intel CPUs, there's a built-in technology Turbo Boost which turns the clock speed up while we're on some heavy work and returns to a low frequency when the work is done or the CPU is going to overheat due to bad cooling(or work on a higher clock speed for too long).

    Before I go into more detail, I'm testing(using) an MBP 2017 with this CPU "3.1GHz quad-core Intel Core i7, Turbo Boost up to 4.1GHz, with 8MB shared L3 cache"

    When I'm using a Mac application, the turbo boost is always working. If I build a project in Android Studio, the CPU frequency goes up to 3.8GHz in my observation(don't know if it actually goes up to 4.1GHz, doesn't matter since it is at least boosted).

    However, when I'm on PD Win VM, even if I build a big project in VS which consumes almost all CPU on the VM and consumes around 50-60% of CPU on the Mac(I allocate 4 logic cores to VM which is the recommended setting), Turbo boost is not triggered, CPU is running constantly in a frequency of 2.2-2.5 GHz, rarely goes to 3GHz.

    I know this could be a difficult issue to solve as it involves a hardware technology(maybe Mac's CPU management as well) but if our VM can trigger Turbo Boost, our peak(period) performance can be boosted ~50%(the calculation is (3.8-2.5)/2.5).

    Any idea on this?
     
  2. Hemnath@Parallels

    Hemnath@Parallels Parallels Support

    Messages:
    1,128
    Hello mdz.
    This seems to be an unexplored technical aspect of Parallels virtualization. A productive course of action might be to post your concern in this regard as a feature request here. This page is under constant review by the management and developers.
     
  3. Ilya Verbin

    Ilya Verbin Bit Poster

    Messages:
    8
    I've just performed an experiment on MBP 2015 with 2.5GHz Intel Core i7.

    Intensive task on macOS:
    Screen Shot 2018-07-12 at 16.03.50.png

    Intensive task in a virtual machine:
    Screen Shot 2018-07-12 at 16.19.32.png
     
    mdz likes this.
  4. mdz

    mdz Bit Poster

    Messages:
    9
    Thanks for your interest.
    May I know what's your guest OS and how intensive the task is?
     
  5. Ilya Verbin

    Ilya Verbin Bit Poster

    Messages:
    8
    Windows 10.
    Just a simple "while (true) { ... };" loop, which causes 100% CPU usage.
     
  6. mdz

    mdz Bit Poster

    Messages:
    9
    Okay that's weird. It does not even hit 3GHz when I build my project in VS (100% CPU usage, cpu temp below 90).
    I will try while true later on see if it is because of the different task
     

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