HP Workstations support Hyper-Threading Technology on systems installed with Red Hat Linux®
versions 8.0, 9, Enterprise Linux WS 3, or a later release. HT Technology is disabled in the BIOS by
default. It must be enabled and run with an SMP (symmetric multiprocessing) kernel. HT Technology is
not supported on AMD processors.
What is Hyper-Threading Technology?
HT Technology is a high performance technology, developed by Intel®, that allows a single processor
to execute multiple threads of instructions simultaneously. HT Technology enables the processor to
utilize its execution resources more efficiently, delivering performance increases and improving user
productivity. Not all systems or applications benefit from the HT Technology. For more information
about the HT Technology, visit the Intel website at
Notes, Limitations, and Requirements
• HT Technology is not supported on earlier platforms, such as the xw4000 and xw5000.
• HT Technology is not supported on dual core or AMD® platforms such as the xw4300 and
• Systems must be using one or two Intel Pentium®4/Xeon processors.
• Red Hat process schedulers support 4 logical CPUs (or 2 CPU pairs with HT Technology) on the HP
Workstation xw8000/xw8200 and xw6000/xw6200 and 2 logical CPUs on the
• Systems with above normal disk I/O activity might experience better performance using SCSI drives
instead of IDE or SATA drives. SCSI drives take better advantage of the increased simultaneous
reads/writes provided with HT Technology.
• An SMP kernel is required.
• Some kernels prior to 2.4.20 produce boot hangs or system hangs while running hyper-threaded
applications. If this occurs, download the latest SMP kernel from
• HP Linux Installer Kit CDs and preinstalled versions of Red Hat + HP Additions have been tested
using HT Technology. Some versions contain kernels that work and others do not.