AMD Finally Releases Overdue Linux CPPC Driver

[harlan4096]

The new driver will optimize Ryzen CPUs for Linux

As reported by Phoronix, AMD's Zen 3 architecture is getting support for the ACPI CPPC driver designed for Linux-based operating systems. The Collaborative Processor Performance Control driver allows Linux to see which cores have the highest boosting potential in a Ryzen CPU and target the highest boosting cores for single- or lightly-threaded workloads, a feature that has been supported in Windows since the launch of the Zen 2 processors. Additionally, the ACPI driver will improve Linux's support of Ryzen power states, allowing for better power consumption and performance. However, the new drivers are currently only for Zen 3, with Zen 2 support coming down the road.

This is much better than the current generic CPUFreq driver built into Linux, which, as the name states, is generic and isn't fully optimized for AMD processors.

Phoronix notes that it's taken AMD two full years to finally release this new CPPC driver for Linux. Originally AMD worked on this driver for Zen 2 processors back in 2019, but the company said it didn't have enough resources to finish the driver during that time.

AMD completed the driver right after Steam announced the Steam Deck with its custom Zen 2 APU and Linux-based Steam OS. AMD made custom adjustments to accommodate thread-targeting specifically for that device, but now it appears that the optimizations have been spread out to all Zen 3 processors in Linux environments. 

Coincidentally, AMD tested the initial P-State patches for Ryzen on Cezanne chips, AMD's latest Ryzen 5000 series APUs comprised of Zen 3 parts. AMD mentions that it will extend the coverage of the CPPC driver in the future, meaning it will eventually support Zen 2 and potentially Zen+ chips.

Phoronix says the code was posted today across 19 patches, so if you want the direct code, you can download it now. But, for more mainstream users, you'll have to wait for a little while before your favorite Linux distro gets updated with the new CPPC driver.
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