Unlock 8 Virtual Cores on rMBP

Discussion in 'MacBook Pro' started by Squilly, Feb 4, 2013.

  1. macrumors 68020

    Squilly

    Joined:
    Nov 17, 2012
    Location:
    PA
    #1
    I was told there was a way to unlock all cores on a rMBP by starting 8 chess games with computer vs computer. The problem: I can only start one. How do you start multiple games?
     
  2. macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    上海 (Shanghai)
    #2
    What do you mean "unlock" cores?

    It's just a computer. It comes working with 8 logical processors.
     
  3. simsaladimbamba

    Joined:
    Nov 28, 2010
    Location:
    located
    #3
    Why do you want to do what?

    Your Mac has one CPU with four real cores, each core having two virtual cores, giving you eight virtual cores as a whole, and if an application is written to take advantage of those, it will use them if it needs to. No need to "unlock" something.

    And how many threads is that today? 10?
     
  4. macrumors 65816

    duervo

    Joined:
    Feb 5, 2011
    #4
    OS X does not support CPU affinity for individual processes. AFAIK, the kernel handles the distribution of processes amongst a CPU's cores. There is no way that I know of to force a process to run on a specific CPU core.
     
  5. macrumors 604

    thejadedmonkey

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    Pa
    #5
    Couldn't you do that dev > null terminal command 8 times to max out the CPU?
     
  6. macrumors member

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    Western Montana
  7. thread starter macrumors 68020

    Squilly

    Joined:
    Nov 17, 2012
    Location:
    PA
    #7
    Just to stress the computer, see what it can do, that's all. I was told by someone that it's recommended.
     
  8. macrumors 6502

    Joined:
    Sep 17, 2012
    #8
    Ask it to play global thermal nuclear warfare. It will unlock all 1024 cores. :)
     
  9. simsaladimbamba

    Joined:
    Nov 28, 2010
    Location:
    located
    #9
    Then run benchmarks like Cinebench (nice visual thing), Xbench or GeekBench or some others. Or install HandBrake and convert some already ripped DVDs.
     
  10. macrumors 6502a

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  11. thread starter macrumors 68020

    Squilly

    Joined:
    Nov 17, 2012
    Location:
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    #11
    I'm on it. Don't get it at all though.
     
  12. macrumors 65816

    duervo

    Joined:
    Feb 5, 2011
    #12
    You could, but that doesn't guarantee that each one will be pinned to a separate core.

    OS X provides no method for CPU affinity. Running a process 8 times is no guarantee that each instance will get its own CPU core for its life ... It probably will, but no guarantees. For example. a scheduled process could start that could temporarily move one of those 8 instances to a core already in use by one of its siblings.

    CPU affinity lets you tie a process to a single core for its entire life.

    Windows NT (and newer can do it per process), as can Linux (for the past 7 or 8 years or so).

    OS X doesn't ... at least anywhere I could find in any if the docs on darwin. Leaving such work up to the kernel CPU scheduler itself. Trust in the kernel, in other words.
     
  13. Moderator

    Nermal

    Staff Member

    Joined:
    Dec 7, 2002
    Location:
    Whakatane, New Zealand
    #13
    You need to duplicate (Cmd-D) Chess.app.
     
  14. thread starter macrumors 68020

    Squilly

    Joined:
    Nov 17, 2012
    Location:
    PA
    #14
    Doesn't work. Press cmd+D in the app?
     
  15. simsaladimbamba

    Joined:
    Nov 28, 2010
    Location:
    located
    #15
    Go to the Applications folder, select Chess.app and then press CMD+D, as CMD+D is a Finder keyboard shortcut for "duplicating" files and folders.

    Also know, that you can use an avatar now.
     
  16. thread starter macrumors 68020

    Squilly

    Joined:
    Nov 17, 2012
    Location:
    PA
    #16
    Dually noted and yay! Thanks.
    Edit: worked. Fan is blowing like crazy with ridiculous lag and getting increasingly hot. Damn...

    ----------

    Fans are blasting!
    [​IMG]
     
  17. simsaladimbamba

    Joined:
    Nov 28, 2010
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    located
    #17
    That is what you get with CPU intensive applications using the CPU, and the following FAQ should you inform you about that: Those Macs in their heat - a sine of over-heating? - a short story by Mister GGJstudios
     
  18. macrumors 6502

    hansenc

    Joined:
    Jun 16, 2004
    #18
    Actually Command + N will open new windows of the chess game without all the work to copy the app over and over again.
     
  19. Moderator

    Nermal

    Staff Member

    Joined:
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    Location:
    Whakatane, New Zealand
    #19
    I didn't know about that when I made my earlier post (I was at work), but Cmd-N seems to be really flaky; I just did it three times and it only generated one additional game.
     
  20. macrumors 601

    derbothaus

    Joined:
    Jul 17, 2010
    #20
    man renice
     
  21. macrumors member

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  22. macrumors 65816

    duervo

    Joined:
    Feb 5, 2011
    #22
    renice changes process priority. It has nothing to do with CPU affinity.
     
  23. macrumors 6502

    Joined:
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    Location:
    Earf
    #23
    HAHAHA! this MF had me thinking of the Whopr when I read the op!
     
  24. macrumors 68030

    Joined:
    Feb 13, 2012
    Location:
    Perth, Western Australia
    #24
    Handbrake to rip a DVD (or ISO of one) is a good stress test. It will max all 8 virtual cores on my MBP.
     
  25. macrumors 601

    derbothaus

    Joined:
    Jul 17, 2010
    #25

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