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Unlike my old Windows Boxes and Linux Boxes, I do not have access of something similar to a BIOS on my MacBook Pro.

I want to disable Intel i7's HyperThreading (so 4 cores look like 4 cores and don't try to simulate extra ones).

There are solutions for disable HT via developer tools temporarily, but I need something to do it permanently (one that does not reset on reboots).

This is for a MacBook Pro 15" Retina.

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  • Does the last entry in this thread apply to your case?
    – harrymc
    Sep 10, 2012 at 5:42
  • Well, does it or does it not ?
    – harrymc
    Sep 14, 2012 at 20:17
  • Nothing worked.
    – Sid
    Oct 1, 2012 at 17:19

2 Answers 2

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Download and install Xcode. It includes a Processor.prefPane (not sure where it's located exactly) that allows you to disable hyperthreading.

With Xcode installed, you can also disable hyperthreading using the following terminal command:

hwprefs cpu_ht=false

I don't believe this setting is retained after restarting your Mac, so you might want to create an AppleScript to run that command on startup.

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  • This method is disabled on sleep as well, thats why I asked a permanent method.
    – Sid
    Aug 30, 2012 at 20:36
  • 1
    These no longer work on Yosemite: the hwprefs command is gone and the Processor.prefPane panel no longer loads. Feb 14, 2015 at 1:56
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Any luck with the following? Requires a reboot to take.

$ sudo nvram SMT=0

Might be something you can put in boot-args as well but I couldn't find it.

$ sudo nvram boot-args=""

Ref: Technical Q&A QA1141 Disabling Processor Cores on a Multi-Core System

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  • Resets on restart. Already tried this.
    – Sid
    Sep 13, 2012 at 7:11
  • It shouldn't reset if you put it in the boot-args, @Sid . You must have skipped that step.
    – cutrightjm
    Sep 15, 2012 at 20:44

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