AMD Posts New "AMD-PSTATE" CPUFreq Driver Leveraging CPPC For Better Perf-Per-Watt

[pete910]

The first version for amd-pstate is to support one
of the Zen3 processors, and we will support more in future after we verify
the hardware and SBIOS functionalities.

Do we know which Zen3 CPU ? Bet it's not the one I have.

[RealNC]

Meanwhile on Zen 2 and kernel 5.10, I assume schedutil is the best general-purpose governor, not ondemand?

[Namelesswonder]

Do we know which Zen3 CPU ? Bet it's not the one I have.

Appears to just be Cezanne and Renoir APUs at the moment. Tests in the patch look to be done on a 5900HX laptop. Tried patching my kernel and enabling the driver but it doesn't load the module for me on my 5900X desktop.

[ciupenhauer]

Do we know which Zen3 CPU ? Bet it's not the one I have.

how can they even target just once damn cpu? doesnt even make sense. I'm betting it's the whole line. or maybe just the H series or U series?

[cbxbiker61]

I'm in the process of bringing up a Lenovo Ideapad 5 Pro with a Ryzen 7 5800H. It's pretty exciting times for those of us who favor AMD chips. The Ideapad 5 Pro seems to be a heck of a solid computer for Linux. I have two outstanding issues to sort out. 1. getting trackpad working with my custom kernel (it does work under Ubuntu). 2. getting the backlit keyboard control working (doesn't work under Ubuntu). I ordered it on Newegg. It came in a CostCo box. I stayed away from the version with Nvidia graphics, so I don't have to mess with Nvidia driver crap on Linux.

Update: Keyboard backlight control works! It helps if you use the correct keys....FN+SPACEBAR.

[Michael]

Appears to just be Cezanne and Renoir APUs at the moment. Tests in the patch look to be done on a 5900HX laptop. Tried patching my kernel and enabling the driver but it doesn't load the module for me on my 5900X desktop.

It didn't work for me on one of my 5900X systems but did work on one of my 5950X systems.

[avem]

Considering the Zen3's performance-per-watt was already good, this is a surprising and welcome change.

That's true however Zen 2/3 CPUs idle power consumption is simply horrible. My 5800X idles at ... ~21W. Hopefully AMD will address it sooner that later but I don't have much hope for Zen 3+ CPUs. Maybe in time for Zen4 AMD will finally be able to compete on this metric with the competition.

Speaking of this news: it's truly great, albeit four years late. Maybe Valve can push AMD to release the documentation for Zen CPUs MSRs as well to enable proper and full monitoring which is simply cringe worthy at the moment.

Here's what you can see in Windows:



Here's what you get in Linux:

k10temp-pci-00c3
Adapter: PCI adapter
CPU Primary T Control:  +34.6°C  
Tdie:                   +34.6°C  
Tccd1:                  +29.8°C

[avem]

Is this supposed to land in 5.15 or later? Article doesn't mention

These are just patches and they haven't even reached staging yet, so 5.15 will definitely not include them, so maybe we'll get the driver in 5.16. Nothing stops you from compiling and using it right now.

BTW, here's a properly formatted LKML post which is easier to read: https://lkml.org/lkml/2021/9/8/542

Patch v2 will be coming soon: https://lkml.org/lkml/2021/9/9/244

[Namelesswonder]

It didn't work for me on one of my 5900X systems but did work on one of my 5950X systems.

Same motherboard and firmware for both systems? I noticed that in your GCC11 PGO article you were testing with the 5950X, Crosshair 8 Hero, and version 3801 firmware. I have the same motherboard and firmware, but a 5900X.

I made sure CPPC was enabled in the AMD CBS page for my motherboard, and even checked that the _CPC objects appear in the ACPI tables, but no dice. Wonder if AGESA is responsible.

[reba]

Appears to just be Cezanne and Renoir APUs at the moment. Tests in the patch look to be done on a 5900HX laptop.

Oh boy, I won the lottery

brand = "AMD Ryzen 9 5900HX with Radeon Graphics "

That's true however Zen 2/3 CPUs idle power consumption is simply horrible. My 5800X idles at ... ~21W. Hopefully AMD will address it sooner that later but I don't have much hope for Zen 3+ CPUs.

This laptop right here idles at around 4-5 Watt (says powertop) / 1.8 Watt (says s-tui) with disabled dGPU but WiFi on, KDE and normal backlight brightness. I have pictures to prove it if necessary