Linux in The News 10-10-22
Last Updated on October 10, 2022 by KC7NYR
AMD CPUs will be more efficient in Linux
P-State EPP driver for AMD hardware is being updated to improve the efficiency of the CPUs; will land in kernel 6.2.
- AMD’s P-State EPP drivers are currently being updated to improve the efficiency of the AMD CPUs by balancing its power draw in different situations.
- The updated P-State EPP driver is capable of gathering and using the ACPI CPPC EPP information to adjust the state of the CPU.
- The new driver will not be merged to Linux kernel 6.1, because it is not ready yet. The new driver is expected to be mainlined with kernel 6.2.
CPUs evolved severely in the last couple of years, alongside GPUs; they both became much more intelligent to adjust their clock speeds while sitting idle or under heavy load. The old CPUs were sitting at 3 GHz even if you were simply looking at the screen, not even moving the mouse. With the changes in the algorithms, even the most powerful CPUs draw a little power when they “decide” it is time to lower the voltage.
Efficiency mode vs performance mode
The early benchmarks confirm that the updated P-State EPP driver improves the efficiency
The P-State EPP (Energy Performance Preference) drivers for AMD CPUs in Linux systems are updated. P-State is where the CPU is under load; the algorithms help the CPU to change its clock speeds depending on the temperature, while also trying to keep the power consumption as low as possible depending on the load. And now, with the changes in the P-State EPP driver, AMD CPUs can deliver better performance-per-watt.
Better efficiency in the P-State EPP drivers is achieved by implementing the use of ACPI CPPC EPP information as well. With this information, the CPU can decide to run in efficiency mode or performance mode, depending on the software it is currently running. Some early benchmarks confirm that the new driver indeed makes a difference in performance-per-watt.
The new driver is expected to be implemented in the Linux kernel 6.2 release. While the kernel 6.1 merge window is currently open, the driver is not ready to be merged yet.