how to determine / disable if simultaneous multi-threading (SMT) is enabled in AIX

Your system is capable of SMT if it's a POWER5-based system running AIX 5L Version 5.3.

To determine if it is enabled:

# smtctl

Example:

smtctl

How to disable simultaneous multi-threading (SMT) in AIX:

Your system is capable of SMT if it's a POWER5-based system running AIX 5L Version 5.3.

To disable smt:

# smtctl -m off [ -w boot | now]

Note: If neither the -w boot or the -w now options are specified, then the mode change is made immediately. It persists across subsequent reboots if you run the bosboot command before the next system reboot.

Example:

smtctl -m off