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EST(4)			 BSD Kernel Interfaces Manual			EST(4)

NAME
     est -- Enhanced Speedstep Technology

SYNOPSIS
     To	compile	this capability	into your kernel place the following line in
     your kernel configuration file:

	   device cpufreq

DESCRIPTION
     The est interface provides	support	for the	Intel Enhanced Speedstep Tech-
     nology.

     Note that est capabilities	are automatically loaded by the	cpufreq(4)
     driver.

LOADER TUNABLES
     The est interface is intended to allow cpufreq(4) to access and implement
     Intel Enhanced SpeedStep Technology via acpi(4) and the acpi_perf inter-
     face accessors.  If the default settings are not optimal, the following
     sysctls can be used to modify or monitor est behavior.

     hw.est.msr_info
	     Attempt to	infer information from direct probing of the msr.
	     Should only be used in diagnostic cases (default 0)

     hw.est.strict
	     Validate frequency	requested is accepted by the cpu when set.  It
	     appears that this will only work on single	core cpus.  (default
	     0)

DIAGNOSTICS
     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.

COMPATIBILITY
     est is only found on supported Intel CPUs.

SEE ALSO
     cpufreq(4)

     Intel 64 and IA-32	Architectures Software Developer Manuals,
     http://www.intel.com/content/www/us/en/processors/architectures-software-
     developer-manuals.html.

AUTHORS
     This manual page was written by Sean Bruno	<sbruno@FreeBSD.org>.

BSD				 June 12, 2012				   BSD

NAME | SYNOPSIS | DESCRIPTION | LOADER TUNABLES | DIAGNOSTICS | COMPATIBILITY | SEE ALSO | AUTHORS

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