Phoronix has discovered interesting new Linux kernel patches designed for Intel Core Ultra "Meteor Lake" processors. According to Monday morning reports, internal software engineers are working on implementing default power profile adjustments. Since their launch in December 2023, Meteor Lake CPUs have been operating on a default "balanced_performance" mode. The Linux adjustments will impact the processor's Energy Performance Preference (EPP) under Linux, similar to Windows Power Plans.
Michael Larabel, the head of Phoronix, provided some background information: "We have previously seen EPP overrides and tuning in the Intel P-State driver for earlier generations of Intel processors, and this is a similar situation here. The ACPI EPP value typically ranges from 0 to 255 to indicate the processor/system power to performance preference."
Looking at the current situation, Larabel stated: "Up to now, the Intel P-State EPP override/tuning has been focused on the default 'balanced_performance' mode. The first patch released on Monday allows for model-specific EPP overrides for all pre-defined EPP strings. The second patch updates the EPP values for Meteor Lake, setting the balanced_performance default to 115 instead of 128, and the 'performance' EPP to 16 instead of 0." Larabel expressed hope that a public release will coincide with the upcoming Linux v6.9 cycle.
Intel software engineers believe that their tweaks and overrides have led to improved performance results for small form factor devices, while also reducing CPU temperatures and thermal throttling. Meteor Lake is considered to be less energy efficient compared to similar mobile processor architectures from AMD and Apple. The next-generation Arrow Lake family from Team Blue is expected to launch later this year, but current CPUs require some optimization in the meantime.
Intel Meteor Lake override patch explanation: "The default balanced_performance EPP has been updated to 115 and the performance EPP to 16. Changing the balanced_performance EPP has shown better performance per watt compared to the default powerup EPP value of 128. Changing the performance EPP to 0x10 results in reduced power consumption for similar performance as EPP 0. This is beneficial for small form factor devices as lower power leads to lower CPU and skin temperatures, reducing thermal throttling and improving performance."
