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diff --git a/documentation/content/en/books/handbook/config/_index.adoc b/documentation/content/en/books/handbook/config/_index.adoc
--- a/documentation/content/en/books/handbook/config/_index.adoc
+++ b/documentation/content/en/books/handbook/config/_index.adoc
@@ -1335,6 +1335,59 @@
This chapter demonstrates how to configure ACPI on FreeBSD. It then offers some tips on how to debug ACPI and how to submit a problem report containing debugging information so that developers can diagnosis and fix ACPI issues.
+[[cpufreq]]
+=== CPU Frequency Control
+
+FreeBSD includes a generic man:cpufreq[4] driver to allow the administrator, or software such as man:powerd[8] and package:sysutils/powerdxx[], to manage the frequency of the CPU to achieve the desired balance between performance and economy.
+A lower setting will save power while reducing the heat generated by the CPU.
+A higher setting will increase performance at the cost of using additional power and generating more heat.
+
+[[est]]
+=== Intel(R) Enhanced Speed Step(TM)
+
+The Intel(R) Enhanced Speed Step(TM) driver, man:est[4], replaces the generic man:cpufreq[4] driver for CPUs that provide this feature.
+The CPU frequency can be statically adjusted using man:sysctl[8], or with the `/etc/rc.d/power_profile` startup script.
+Additional software, such as man:powerd[8] or package:sysutils/powerdxx[], can be used to automatically adjust the CPU frequency based on processor utilization.
+
+Each supported frequency, along with its expected power consumption, can be listed by examining the man:sysctl[3] tree:
+
+```
+root@host:~ # sysctl dev.cpufreq.0.freq_driver dev.cpu.0.freq_levels dev.cpu.0.freq
+dev.cpufreq.0.freq_driver: est0
+dev.cpu.0.freq_levels: 3001/53000 3000/53000 2900/50301 2700/46082 2600/43525 2400/39557 2300/37137 2100/33398 2000/31112 1800/27610 1700/25455 1500/22171 1400/20144 1200/17084 1100/15181 900/12329 800/10550
+dev.cpu.0.freq: 800
+```
+
+A frequency 1 MHz higher than the maximum frequency of the CPU indicates the Intel(R) Turbo Boost(TM) feature.
+
+[[hwpstate_intel]]
+=== Intel Speed Shift(TM)
+
+Users running newer Intel(R) CPUs may find some differences in dynamic frequency control when upgrading to FreeBSD 13.0.
+A new driver for the Intel(R) Speed Shift(TM) feature set, available on certain SKUs, exposes the ability for the hardware to dynamically vary the core frequencies, including on a per core basis.
+FreeBSD 13.0 comes with the man:hwpstate_intel[4] driver to automatically enable Speed Shift(TM) control on equipped CPUs, replacing the older Enhanced Speed Step(TM) man:est[4] driver.
+The man:sysctl[8] `dev.cpufreq.%d.freq_driver` will indicate if the system is using Speed Shift.
+
+To determine which frequency control driver is being used, examining the `dev.cpufreq.0.freq_driver` oid.
+```
+root@host:~ # sysctl dev.cpufreq.0.freq_driver
+dev.cpufreq.0.freq_driver: hwpstate_intel0
+```
+
+This indicates that the new man:hwpstate_intel[4] driver is in use.
+On such systems, the oid `dev.cpu.%d.freq_levels` will show only the maximum CPU frequency, and will indicate a power consumption level of `-1`.
+The current CPU frequency can be determined by examining the `dev.cpu.%d.freq` oid.
+
+```
+root@host:~ # sysctl dev.cpu.0.freq_levels dev.cpu.0.freq
+dev.cpu.0.freq_levels: 3696/-1
+dev.cpu.0.freq: 898
+```
+
+For more information, including on how to balance performance and energy use, and on how to disable this driver, refer to the man page man:hwpstate_intel[4].
+
+Note: Users accustomed to using man:powerd[8] or package:sysutils/powerdxx[] will find these utilities have been superseded by the man:hwpstate_intel[4] driver and no longer work as expected.
+
[[acpi-config]]
=== Configuring ACPI
diff --git a/website/content/en/releases/13.0R/relnotes.adoc b/website/content/en/releases/13.0R/relnotes.adoc
--- a/website/content/en/releases/13.0R/relnotes.adoc
+++ b/website/content/en/releases/13.0R/relnotes.adoc
@@ -398,7 +398,9 @@
Added the man:axp[4] driver, supporting the 10G ethernet controller found on
AMD EPYC processors. gitref:7113afc84c0[repository=src]
-Added support for Intel Speed Shift to man:cpufreq[4].
+man:cpufreq[4] now includes support for Intel HW P-States (Speed Shift(TM)) via the new man:hwpstate_intel[4] driver.
+On systems equipped with Speed Shift(TM), users of man:powerd[8] or package:sysutils/powerdxx[] may find that these utilities no longer work as expected, as they are superseded by this driver.
+For more information, see the link:{handbook}config/#hwpstate_intel[FreeBSD Handbook].
gitref:4577cf3744b[repository=src]
Added a driver for pwm-backlight compatible devices, such as the one found on

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