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est(4) [freebsd man page]

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

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 Technology. 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 interface 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) SYSCTL VARIABLES
The following sysctl(8) values are available dev.est.%d.desc Description of support, almost always Enhanced SpeedStep Frequency Control. dev.est.0.%desc: Enhanced SpeedStep Frequency Control dev.est.%d.driver Driver in use, always est. dev.est.0.%driver: est dev.est.%d.parent dev.est.0.%parent: cpu0 The cpu that is exposing these frequencies. For example cpu0. dev.est.%d.freq_settings. The valid frequencies that are allowed by this CPU and their step values. 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 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, developer-manuals.html. AUTHORS
This manual page was written by Sean Bruno <>. BSD
October 18, 2012 BSD

Check Out this Related Man Page

cpufreq-info(1) 														   cpufreq-info(1)

cpufreq-info - Utility to retrieve cpufreq kernel information SYNTAX
cpufreq-info [options] DESCRIPTION
A small tool which prints out cpufreq information helpful to developers and interested users. OPTIONS
-c --cpu <CPU> <CPU> number which information shall be determined about. -e --debug Prints out debug information. -f --freq Get frequency the CPU currently runs at, according to the cpufreq core. -w --hwfreq Get frequency the CPU currently runs at, by reading it from hardware (only available to root). -l --hwlimits Determine the minimum and maximum CPU frequency allowed. -d --driver Determines the used cpufreq kernel driver. -p --policy Gets the currently used cpufreq policy. -g --governors Determines available cpufreq governors. -a --related-cpus Determines which CPUs run at the same hardware frequency. -a --affected-cpus Determines which CPUs need to have their frequency coordinated by software. -s --stats Shows cpufreq statistics if available. -y --latency Determines the maximum latency on CPU frequency changes. -o --proc Prints out information like provided by the /proc/cpufreq interface in 2.4. and early 2.6. kernels. -m --human human-readable output for the -f, -w, -s and -y parameters. -h --help Prints out the help screen. REMARKS
You can't specify more than one of the output specific options -o -e -a -g -p -d -l -w -f -y. You also can't specify the -o option combined with the -c option. FILES
/sys/devices/system/cpu/cpu*/cpufreq/ /proc/cpufreq (deprecated) /proc/sys/cpu/ (deprecated) AUTHORS
Dominik Brodowski <> - author Mattia Dongili<> - first autolibtoolization SEE ALSO
cpufreq-set(1), cpufreq-aperf(1) Mattia Dongili 0.1 cpufreq-info(1)
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