HP OpenVMS 8.x manual Shell cpuconfig

For more information about using EFI, see the documentation provided for your Integrity server. Extensive information can also be found online at:

http://developer.intel.com/technology/efi/help/efidocs.htm

A.4 Enabling or Disabling Hyper-Threading on Dual-Core Processors

Systems that have Intel Itanium® Dual-Core processors can support Hyper-Threading. Hyper-Threading provides the ability for processors to create an additional logical CPU that might allow additional efficiencies of processing. For example, a dual-core processor with Hyper-Threading active provides four logical CPUs, two on each core. The effect that Hyper-Threading has on performance depends heavily on the applications running on your system. HP recommends that you start with Hyper-Threading disabled and experiment later, if you wish.

You can enable or disable Hyper-Threading for a system whose processors support it. To display the Hyper-Threading state for a system, use the EFI info cpu or cpuconfig command. (The display indicates that “CPU threads” are turned on or off.) For example:

Shell> cpuconfig

PROCESSOR MODULE INFORMATION

	# of		L3	L4	Family/
CPU	Logical		Cache	Cache	Model		Processor
Module	CPUs	Speed	Size	Size	(hex.)	Rev	State
-----	-------	------	------	------	---------	---	-----
0	4	1.4 GHz	6 MB	None	20/00	CO	Active

CPU threads are turned on.

To enable or disable Hyper-Threading, use the EFI cpuconfig threads on or cpuconfig threads off command. For more information, enter help cpuconfig at the EFI Shell prompt or see the appropriate hardware documentation. The recent release of the Partition Manager also supports Hyper-Threading.

After enabling or disabling Hyper-Threading, the system must be reset for the change to take effect. Use the EFI Shell reset command. When Hyper-Threading is enabled, it remains active on the next reboot of the system.

A.5 Configuring and Managing OpenVMS Booting on Integrity Servers

This section explains how to configure and manage the booting behavior of your Integrity server. You can use the EFI Boot Manager (while the operating system is not running) or the OpenVMS I64 Boot Manager (while the operating system is running) to configure boot options. HP recommends using the latter.

You can configure multiple boot entries for a single operating system. On a cell-based Integrity server running multiple operating systems, you can configure boot options for all currently installed operating systems. On cell-based servers, each nPartition has a local instance of EFI that is specific to that partition. Each partition can be booted and stopped independently of other nPartitions in the system, and each partition executes its own operating system image.

On cell-based servers, to successfully boot an operating system you must first ensure that the ACPI configuration is correct for the operating system being booted, as explained in Section A.5.1 (page 165). Each nPartition has its own ACPI configuration value.

IMPORTANT: To configure booting on a Fibre Channel storage device, you must use the OpenVMS I64 Boot Manager utility. (For information about configuring Fibre Channel devices, see Appendix D (page 241).) HP also recommends using this utility to add members of a multiple-member shadow set to the boot device list and dump device list. Be sure to add all members to both lists.

If you have just completed the initial setup of your Integrity server, perform the following steps before continuing:

164 Configuring OpenVMS I64 Hardware Operation and Boot Operations, and Booting and Shutting Down Your System