This driver provides a P state for Intel core processors. The driver implements an internal governor and will become the scaling driver and governor for Sandy bridge processors. When this driver is enabled it will become the preferred scaling driver for Sandy bridge processors. If in doubt, say N.
This driver adds support for the PCC interface. For details, take a look at: <file:Documentation/admin-guide/pm/cpufreq_drivers.rst>. To compile this driver as a module, choose M here: the module will be called pcc-cpufreq. If in doubt, say N.
This driver adds a CPUFreq driver which utilizes the ACPI Processor Performance States. This driver also supports Intel Enhanced Speedstep and newer AMD CPUs. To compile this driver as a module, choose M here: the module will be called acpi-cpufreq. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
The powernow-k8 driver used to provide a sysfs knob called "cpb" to disable the Core Performance Boosting feature of AMD CPUs. This file has now been superseded by the more generic "boost" entry. By enabling this option the acpi_cpufreq driver provides the old entry in addition to the new boost ones, for compatibility reasons.
This adds the CPUFreq driver for AMD Elan SC400 and SC410 processors. You need to specify the processor maximum speed as boot parameter: elanfreq=maxspeed (in kHz) or as module parameter "max_freq". For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
This adds the CPUFreq driver for AMD Elan SC520 processor. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
This adds the CPUFreq driver for mobile AMD K6-2+ and mobile AMD K6-3+ processors. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
This adds the CPUFreq driver for mobile AMD K7 mobile processors. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
This adds the CPUFreq driver for K8/early Opteron/Athlon64 processors. Support for K10 and newer processors is now in acpi-cpufreq. To compile this driver as a module, choose M here: the module will be called powernow-k8. For details, take a look at <file:Documentation/cpu-freq/>.
This adds AMD-specific powersave bias function to the ondemand governor, which allows it to make more power-conscious frequency change decisions based on feedback from hardware (available on AMD Family 16h and above). Hardware feedback tells software how "sensitive" to frequency changes the CPUs' workloads are. CPU-bound workloads will be more sensitive -- they will perform better as frequency increases. Memory/IO-bound workloads will be less sensitive -- they will not necessarily perform better as frequency increases. If in doubt, say N.
This add the CPUFreq driver for NatSemi Geode processors which support suspend modulation. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
This is deprecated and this functionality is now merged into acpi_cpufreq (X86_ACPI_CPUFREQ). Use that driver instead of speedstep_centrino. This adds the CPUFreq driver for Enhanced SpeedStep enabled mobile CPUs. This means Intel Pentium M (Centrino) CPUs or 64bit enabled Intel Xeons. To compile this driver as a module, choose M here: the module will be called speedstep-centrino. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
Use built-in tables for Banias CPUs if ACPI encoding is not available. If in doubt, say N.
This adds the CPUFreq driver for certain mobile Intel Pentium III (Coppermine), all mobile Intel Pentium III-M (Tualatin) and all mobile Intel Pentium 4 P4-M on systems which have an Intel ICH2, ICH3 or ICH4 southbridge. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
This adds the CPUFreq driver for certain mobile Intel Pentium III (Coppermine), all mobile Intel Pentium III-M (Tualatin) on systems which have an Intel 440BX/ZX/MX southbridge. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
This adds the CPUFreq driver for Intel Pentium 4 / XEON processors. When enabled it will lower CPU temperature by skipping clocks. This driver should be only used in exceptional circumstances when very low power is needed because it causes severe slowdowns and noticeable latencies. Normally Speedstep should be used instead. To compile this driver as a module, choose M here: the module will be called p4-clockmod. For details, take a look at <file:Documentation/cpu-freq/>. Unless you are absolutely sure say N.
This adds the CPUFreq driver for FSB changing on nVidia nForce2 platforms. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
This adds the CPUFreq driver for Transmeta Crusoe and Efficeon processors which support LongRun. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
This adds the CPUFreq driver for VIA Samuel/CyrixIII, VIA Cyrix Samuel/C3, VIA Cyrix Ezra and VIA Cyrix Ezra-T processors. For details, take a look at <file:Documentation/cpu-freq/>. If in doubt, say N.
This adds the CPUFreq driver for VIA C7 processors. However, this driver does not have any safeguards to prevent operating the CPU out of spec and is thus considered dangerous. Please use the regular ACPI cpufreq driver, enabled by CONFIG_X86_ACPI_CPUFREQ. If in doubt, say N.
Don't perform all checks for a speedstep capable system which would normally be done. Some ancient or strange systems, though speedstep capable, don't always indicate that they are speedstep capable. This option lets the probing code bypass some of those checks if the parameter "relaxed_check=1" is passed to the module.