AMD is preparing Linux 7.4 to properly handle Zen 6 client chips, with fresh P-State tuning for three core classes.
According to Phoronix the changes target AMD P-State Energy Performance Preference, or EPP, because Zen 6 client firmware handles those values differently from earlier platforms. AMD says platform-specific tuning is needed to balance performance and power consumption.
Instead of applying the same settings to every core and hoping for the best, the driver uses separate values for performance, density, efficiency, and new low-power cores. The changes are intended for hybrid Zen 6 client systems.
For the performance profile, all three core types receive an EPP value of 25. Balanced performance uses 51, and balanced power uses 64 across the board.
Things diverge with the power-focused setting. Performance cores stay at 64, while efficiency and low-power cores move to 115, giving Linux considerably more scope to stop the smaller cores behaving like caffeinated desktop silicon.
AMD kernel engineer Mario Limonciello said newer SoCs behave differently and that using identical EPP values everywhere can produce worse results. The driver therefore gains per-SoC and per-core-type policies, falling back to legacy values when no specific tuning exists.
The AMD P-State driver is changing another bit of arithmetic for Zen 6. Boost ratios will be calculated from actual frequency values rather than the arbitrary performance scale used by earlier platforms.
Related Collaborative Processor Performance Control work gives Linux temporary hard-coded maximum-frequency values of 5025 for performance cores, 3524 for efficiency cores and 2399 for the new low-power type. Future ACPI revisions are expected to provide a proper interface instead.
“Newer versions of the ACPI will introduce a proper interface for getting this information, but for now hardcode values so that these systems perform as intended and to unblock future scheduler work while we continue to wait,” AMD’s patch said.
Linux 7.3 has already recognised AMD’s new low-power core type, preventing it from appearing as an unknown core. That work unified vendor-specific AMD and Intel classifications behind generic Linux CPU core types.
The latest Zen 6 EPP patches have been submitted through the Linux power-management subsystem’s next branch and are explicitly marked for Linux 7.4. Its merge window is expected to open during the second half of October, with a stable release potentially arriving by the end of December.
Linux 7.4 is shaping up to contain more than CPU housekeeping for AMD users. Separate AMDGPU work is set to enable HDMI 2.1 by default with FreeSync, variable refresh rate and Auto Low Latency Mode, while Phoronix notes rumours placing the first next-generation Ryzen launches around CES or during the first half of 2027.
