Intel Core Ultra (Lunar Lake/Meteor Lake) EPP Power Profiles

[hanthor]

I'm exploring the power savings from using the EPP profiles Intel has written ( think because theuy didn't have time to get these added to the kernel) https://www.intel.com/content/www/us/en/developer/articles/tool/epp-tuning-package-linux.html

Here are the changes Intel make in the tuned profiles (performance and powersave) I used to these to verify the power settings and set them to Intel's preferred values

#!/bin/bash

#get current power prof setting
n=$(nproc)
i=0
while [ "$i" -lt $n ]; do
	cat  /sys/devices/system/cpu/cpu$i/cpufreq/energy_performance_preference
	cat  /sys/devices/system/cpu/cpu$i/power/energy_perf_bias
	i=$(( i + 1 ))
done 

#Set to Intel Core Ultra Powersave EPP
n=$(nproc)
i=0
while [ "$i" -lt $n ]; do
	echo 178 | sudo tee  /sys/devices/system/cpu/cpu$i/cpufreq/energy_performance_preference
        echo 8 | sudo tee  /sys/devices/system/cpu/cpu$i/power/energy_perf_bias
        i=$(( i + 1 ))
done

#return to Vanilla powersave
n=$(nproc)
i=0
while [ "$i" -lt $n ]; do
        echo "balance_performance" | sudo tee  /sys/devices/system/cpu/cpu$i/cpufreq/energy_performance_preference
        echo 6 | sudo tee  /sys/devices/system/cpu/cpu$i/power/energy_perf_bias
        i=$(( i + 1 ))
done

#set to Intel Core Ultra Performance EPP
n=$(nproc)
i=0
while [ "$i" -lt $n ]; do
	echo 64 | sudo tee  /sys/devices/system/cpu/cpu$i/cpufreq/energy_performance_preference
	i=$(( i + 1 ))
done 


#Return to Vanilla Performance  
n=$(nproc)
i=0
while [ "$i" -lt $n ]; do
	echo "balance_performance" | sudo tee  /sys/devices/system/cpu/cpu$i/cpufreq/energy_performance_preference
	i=$(( i + 1 ))
done     

[hanthor]

I'm doing 15 min of a 4k youtube video

Vanilla powersave
55% --> 45%

10%

Intel powersave
62% --> 56%

6%

@castrojo looks like it really is ~40% powersavings on video playback

[hanthor]

Looks like these were added to the kernel at some point https://lore.kernel.org/lkml/[email protected]/

[castrojo]

I think it'll live in an hwe image somewhere and not directly in bluefin (bazzite will probably need this too), m2/bsherman will know where to put it.

[hanthor]

the addition for these settings for Meteor Lake are here: https://github.com/torvalds/linux/blame/feffde684ac29a3b7aec82d2df850fbdbdee55e4/drivers/cpufreq/intel_pstate.c#L3660

These should already be set in stable and stable-daily

Lunar Lake doesn't have any EPP profile set. in the kernel rn

[hanthor]

I have a service and script to set these profile automatically here: https://github.com/hanthor/intelepptesting