Disable Hyper-Threading Mountain Lion 10.8 (Speed Up the Mac)

Discussion in 'OS X Mountain Lion (10.8)' started by mx1t, Dec 10, 2012.

  1. mx1t, Dec 10, 2012
    Last edited: Dec 12, 2012

    macrumors newbie

    Dec 10, 2012
    I would like to disable HT from my MacBook Pro Retina running on 10.8 (Mountain Lion)

    I found some solutions on the Internet but they don't work or not enough for me :eek:

    On 10.7 (Lion) this solution works fine but doesn't on 10.8
    OFF: sudo nvram SMT=0
    ON: sudo nvram -d SMT

    The second works on Mountain Lion but it's not permanent.
    Install Xcode->Open Instrument App->Preferences->Disable Hardware Multi-Threading.
    It's not permanent unfortunately, after restating the Mac everything returns to normal.

    The last one (Last Hope :rolleyes: ) works but.....
    sudo nvram boot-args="cpus=4"

    This solution gave me 4 Cores at Activity Monitor (But I'm not sure if it's 2 Cores + 2 Threads or 4 Cores + 0 Threads)
    I beleive it's 2 Cores + 2 Threads because I felt the Mac little bit Slow.

    Now I'm looking for a permanent deactivation of HyperThreading on Mountain Lion.
    Help Please???? :(

    Edit: Why Disable HT From 10.8 ?
    When I disabled HT with Xcode Instrument, my Mac became tooo fast, all applications started fastly even Apple Video Editing apps like iMove and Final Cut Pro.

    Why permanent ?
    For Bootcamp Windows 7.
    I tried Assassin's Creed 3, works fine on rMBP but when I checked Ubisoft Forums, some users said that HT slow down games, also Ubisoft Recommend to disable HT.
  2. macrumors 6502

    Sep 3, 2006
    So, did you run some proper benchmark? Because applications are cached on the ram after the first time you launch them.
  3. thread starter macrumors newbie

    Dec 10, 2012
    I know Ritsuka
    I did the test before the applications are cached on RAM. (restarting Mac)
    Try it by yourself, open Final Cut Pro or a 3D Application Like Autodesk Maya and start Rendering, you'll feel the difference.

    Do you have any solution to disable permanently HT on 10.8?

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