MP 1,1-5,1 Disable Hyperthreading with OpenCore?

[Scrotorr]

I've got a user running a CMP 5,1 as a Windows/Linux CAD/simulation box in one of our labs, and unfortunately the primary program he uses is single thread only. For specific programs like that I would usually disable hyper threading, but I didn't remember seeing a good way to do that. I've been poking around but didn't see a hyperthreading/smt specific variable. Is there one that I'm missing?

Appreciate the help!

 

[tsialex]

Just use the standard way, documented by Apple below:

How to enable full mitigation for Microarchitectural Data Sampling (MDS) vulnerabilities – Apple Support (UK)

This option is available for macOS Mojave, High Sierra, and Sierra after installing security updates.

support.apple.com

macOS, hyperthreading and Microarchitectural Data Sampling vulnerabilities

In 2018, vulnerabilities were publicly disclosed in computer processor architecture which affected the vast majority of desktops, laptops, mobile devices and servers. These vulnerabilities are refe…

derflounder.wordpress.com

 

[Scrotorr]

Just use the standard way, documented by Apple below:

How to enable full mitigation for Microarchitectural Data Sampling (MDS) vulnerabilities – Apple Support (UK)

This option is available for macOS Mojave, High Sierra, and Sierra after installing security updates.

support.apple.com

macOS, hyperthreading and Microarchitectural Data Sampling vulnerabilities

In 2018, vulnerabilities were publicly disclosed in computer processor architecture which affected the vast majority of desktops, laptops, mobile devices and servers. These vulnerabilities are refe…

derflounder.wordpress.com

This machine doesn't have a MacOS install on it at all - only Windows. I know I can do boot-args through OpenCore - but how can I implement the

nvram SMTDisable=%01

 

[tsialex]

This machine doesn't have a MacOS install on it at all - only Windows. I know I can do boot-args through OpenCore - but how can I implement the

I doubt that Windows kernel will understand or even respect this setting, but you can boot Recovery or macOS installer and set nvram SMTDisable=%01 to prove or disprove it, follow the steps on the second link of my previous post.

Btw, if you gonna run Windows, you should check the correct Windows way to disable HT.