Enhanced Speedstep Technology
To compile this capability into your kernel place the following line in your
kernel configuration file:
interface provides support for the
Intel Enhanced Speedstep Technology.
capabilities are automatically
loaded by the
interface is intended to allow
to access and implement Intel Enhanced SpeedStep Technology via
and the acpi_perf interface accessors. If the default settings are not
optimal, the following sysctls can be used to modify or monitor
- Attempt to infer information from direct probing of the msr. Should only
be used in diagnostic cases. (default 0)
- Validate frequency requested is accepted by the cpu when set. It appears
that this will only work on single core cpus. (default 0)
values are available
- Description of support, almost always Enhanced SpeedStep Frequency
- dev.est.0.%desc: Enhanced SpeedStep Frequency Control
- Driver in use, always est.
- dev.est.0.%driver: est
- dev.est.0.%parent: cpu0
- The cpu that is exposing these frequencies. For example
- The valid frequencies that are allowed by this CPU and their step
- dev.est.0.freq_settings: 2201/45000 2200/45000 2000/39581 1900/37387
- 1800/34806 1700/32703 1600/30227 1500/28212 1400/25828 1300/23900
1200/21613 1100/19775 1000/17582 900/15437 800/13723
- est%d: <Enhanced SpeedStep Frequency Control> on cpu%d
Indicates normal startup of this interface.
- est: CPU supports Enhanced Speedstep, but is not recognized.
- est: cpu_vendor GenuineIntel, msr 471c471c0600471c
- device_attach: est%d attach returned 6
Indicates all attempts to attach to this interface have failed. This usually
indicates an improper BIOS setting restricting O/S control of the CPU
speeds. Consult your BIOS documentation for more details.
is only found on supported Intel CPUs.
Intel 64 and IA-32 Architectures
Software Developer Manuals,
This manual page was written by Sean Bruno