nPartition Administrator's Guide, Second Edition

core that can allow additional efficiencies of processing. For example, a dual-core processor with

Hyper-Threading active provides four logical processors, two on each processor core.

CAUTION: Some operating systems do not support Hyper-Threading. Problems can occur

when running an OS that does not support Hyper-Threading on an nPartition that has

Hyper-Threading enabled.

NOTE: You must reset an nPartition when changing its Hyper-Threading status.

Hyper-Threading will not be enabled or disabled until after the nPartition is reset.

Checking the Hyper-Threading Status for an nPartition To check the current Hyper-Threading

status for an nPartition:

• From the EFI Shell: cpuconfig or cpuconfig threads

• From HP-UX: setboot

• Using the Enhanced nPartition Commands: parstatus -T

Example 7-2 Checking the Hyper-Threading Status for an nPartition

# setboot

Primary bootpath : 0/0/1/1/0.12.0

HA Alternate bootpath : 0/0/0/1/0

Alternate bootpath : 0/0/0/1/1

Autoboot is ON (enabled)

Hyperthreading : ON

: OFF (next boot)

The HP-UX setboot command indicates that Hyper-Threading currently is enabled (ON)

for the nPartition.

The next time the nPartition is booted (after it is reset), Hyper-Threading will be disabled

(OFF) for the nPartition.

Enabling Hyper-Threading for an nPartition To enable Hyper-Threading, use any of the following

methods and then reset the nPartition whose Hyper-Threading status you have changed:

• From the EFI Shell: cpuconfig threads on

• From HP-UX: setboot -m on

• Using the Enhanced nPartition Commands: parmodify -pn -T y, where n is the nPartition

number.

• Using Partition Manager: Perform the Modify nPartition task and select the Enable

Hyper-Threading check box on the Configure Memory tab.

You must reset an nPartition after changing its Hyper-Threading status.

Enabling and Disabling Hyper-Threading on Dual-Core Intel® Itanium® 2 Processors 219