A Ryzen 7600 CPU on Fedora 38 was only scaling between 3.0–3.8 GHz instead of the expected 400 MHz–5.17 GHz range. The root cause was the legacy acpi-cpufreq driver being loaded instead of the newer AMD P-State driver. The fix involves installing kernel 6.4 from Fedora's testing repository via koji, then enabling the amd_pstate=enable kernel parameter in GRUB and regenerating the bootloader config. After rebooting, the amd-pstate-epp driver loads correctly, allowing full frequency range scaling down to 400 MHz at idle.
Table of contents
Investigation #Installing the new kernel #Enable the driver #Check it’s working #Conclusion #Sort: