Hey Enjoying this thread. I too try to understand c-states and how to optimize for low power. I run Nixos (25.11) on: Intel Core Ultra 5 225 Asus Strix B860-I (Itx) 32Gb of DDR5 5600Mhz ram Crucial P510 2TB Corsair RM650e I too can only get acpi-idle stats for C1-3 in powertop/turbostat/cpupower. I measured the power draw with blank screen and heavy bios/OS power optimization. I seem to average 15.5W (between 13 and 17). I'm fine with that number but it feels irritating you pay €300 + €200 for a MB and CPU and it doesn't work as advertised.