Linux 6.5 With AMD P-State EPP Default Brings Performance & Power Efficiency Benefits For Ryzen Servers

[Anux]

It seems to be either UEFI or CPU issue, as I still have no confirmed report from a Zen3 desktop CPU user on any UEFI actually seeing the 'cppc' feature flag or checking their pstate driver is using shared_mem=0.

I will see tonight because I'm pretty sure I have the flag, but it's a Zen3 APU. I only have it after activating the CPPC Option in BIOS not with standard Settings.

[Ranguvar]

Maybe it is your distro having strange kernel settings? Try a live medium from arch or something recent/rolling. But it could just be, that your BIOS doesn't support it even in newer versions.

While I'm using the X2APIC patch, I've tested plain Arch kernel as well.

It seems to be either UEFI or CPU issue, as I still have no confirmed report from a Zen3 desktop CPU user on any UEFI actually seeing the 'cppc' feature flag or checking their pstate driver is using shared_mem=0.

[Anux]

Maybe it is your distro having strange kernel settings? Try a live medium from arch or something recent/rolling. But it could just be, that your BIOS doesn't support it even in newer versions.

[Ranguvar]

Look for BIOS updates for your board, the CPU is not the reason.

I just updated the BIOS and ASUS Prime X570 and got hit with a bug. The settings were left on AUTO by default which suggest vendors issue. Workaround is to add parameters.

I updated to the new F37g with AGESA V2 1.2.0.B
I also reset CMOS and tired many combinations of settings

No 'cppc' flag in lscpu regardless.

[finalzone]

I am using F36 BIOS on a Gigabyte X570 Aorus Master, from Dec 28th 2022, with AGESA V2 1.2.0.7.

I tried resetting BIOS completely and changing many other settings but could not get cppc feature flag to show or find anyone else with desktop Zen3 and working cppc flag.

Last time I updated BIOS it was fraught with issues as I have a complex display and boot setup, so I am waiting until something newer releases other than F37f (AGESA V2 1.2.0.A).
No related change notes. If nothing newer releases I will try again in a few weeks.

I just updated the BIOS and ASUS Prime X570 and got hit with a bug. The settings were left on AUTO by default which suggest vendors issue. Workaround is to add parameters.

[Ranguvar]

Quick question, have you updated your motherboard BIOS?
I have a the exact Ryzen 5900X running on ASUS PRIME X570 motherboard supporting amd_pstate=active by default on kernel 6.5.4.

I am using F36 BIOS on a Gigabyte X570 Aorus Master, from Dec 28th 2022, with AGESA V2 1.2.0.7.

I tried resetting BIOS completely and changing many other settings but could not get cppc feature flag to show or find anyone else with desktop Zen3 and working cppc flag.

Last time I updated BIOS it was fraught with issues as I have a complex display and boot setup, so I am waiting until something newer releases other than F37f (AGESA V2 1.2.0.A).
No related change notes. If nothing newer releases I will try again in a few weeks.

[finalzone]

It's due to the 5900X.

Unfortunately 'cppc' feature flag does not appear to be exposed for at least desktop non-APU Zen3.
Test `lscpu` and regardless of BIOS setting, it never shows that flag.

Quick question, have you updated your motherboard BIOS?
I have a the exact Ryzen 5900X running on ASUS PRIME X570 motherboard supporting amd_pstate=active by default on kernel 6.5.4.

[geearf]

Thank you all for your reports!
Could still be UEFI bug.

Could any of you please check `lscpu` for cppc feature flag?
I find it hard to believe even Zen2 has exposed MSRs for CPPC, more likely it's defaulting to shared memory mode..?

Yeah I don't see the flag on my Zen2, that would explain why amd-pstate is not default.

[Ranguvar]

I'm not sure it is due to the CPU. Michael is probably right.
My 5950X is able to use amd_pstate without any options on the cmdline.
And I'm using Linux 6.5.4 too.

Look for BIOS updates for your board, the CPU is not the reason.

Same on my 3800X.

Thank you all for your reports!
Could still be UEFI bug.

Could any of you please check `lscpu` for cppc feature flag?
I find it hard to believe even Zen2 has exposed MSRs for CPPC, more likely it's defaulting to shared memory mode..?

[ATLief]

I’d love to see some comparisons for amd_pstate=passive, especially with the performance governor. That’s what I currently use, but I’d gladly use something else if it yields more performance.

Has anyone compared them?