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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 '12 at 5:42
    
Well, does it or does it not ? –  harrymc Sep 14 '12 at 20:17
    
Nothing worked. –  Sid Oct 1 '12 at 17:19

2 Answers 2

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 '12 at 20:36

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 '12 at 7:11
    
It shouldn't reset if you put it in the boot-args, @Sid . You must have skipped that step. –  ekaj Sep 15 '12 at 20:44

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