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Disabling x86 Hyper-Threading in Oracle Solaris (Doc ID 2434206.1)

Last updated on DECEMBER 16, 2022

Applies to:

Solaris Operating System - Version 10 3/05 and later
Solaris x64/x86 Operating System - Version 10 3/05 and later
Oracle Solaris on x86-64 (64-bit)


 Some x86 processors provide a feature called Hyper-Threading Technology, in which a single processor core runs multiple threads of execution in parallel, sharing the resources of the core.   This comes with tradeoffs for both performance and security, as one thread may be able to starve the other of resources, or determine what the other thread is doing by monitoring the shared resources.   While many workloads work better with Hyper-Threading enabled, for some workloads it is better to disable Hyper-Threading on the system.


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In this Document
 A) Disabling Hyper-Threading in the BIOS:
 B) Dynamic CPU Off-lining:
 Example: Off-lining all but one of each physical processor's logical CPUs:

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