likwid-setFrequencies.md

@@ -16,11 +16,17 @@ likwid-setFrequencies can only be used in conjunction with the `acpi-cpufreq` ke
 -v	 Version information
 -c dom	 Likwid thread domain which to apply settings (default are all CPUs)
 	 See likwid-pin -h for details
--g gov	 Set governor (conservative, ondemand, powersave, performance, turbo) (set to ondemand if omitted)
--f freq	 Set fixed frequency, implicitly sets userspace governor
--p	 Print current frequencies
--l	 List available frequencies
--m	 List available governors
+-g gov	 Set governor (performance, powersave)
+-f/--freq freq	 Set current, minimal and maximal CPU frequency
+-p	 Print current frequencies (CPUs + Uncore)
+-l	 List available CPU frequencies
+-m	 List available CPU governors
+
+-F/--Freq freq	 Set current CPU frequency
+-x/--min freq	 Set minimal CPU frequency
+-y/--max freq	 Set maximal CPU frequency
+--umin freq	 Set minimal Uncore frequency
+--umax freq	 Set maximal Uncore frequency
 ```
 
 ## Usage
@@ -49,6 +55,7 @@ CPU 9: governor  performance frequency 3.001 GHz
 [...]
 ```
 
+Starting with version 4.3.0 the `-p` switch prints also the min/max Uncore frequency.
 
 When you know a valid frequency for a range of CPU cores you can set them:
 ```
@@ -72,6 +79,9 @@ $ likwid-pin -p
 ```
 Prints all available affinity domains, see [[likwid-pin|likwid-pin]] Wiki page.
 
+### Manipulating Uncore frequency on Intel CPUs
+Some Intel CPUs provide the possibility to change the Uncore frequency. You can use the `--umin` and `--umax` command line options to set it. One problem with the Uncore frequency is that the minimal and maximal frequency limits are not readable in all system configurations. Therefore LIKWID defines a range of supported frequencies. To be sure that the frequency you adjusted as requested, measure the `UNCORE_CLOCK` event using `likwid-perfctr`.
+
 ## Configuration of the setFreq daemon
 
 Since the daemon process `likwid-setFreq` requires higher privileges than the control script likwid-setFrequency. There are two methods to grant this to the daemon: