Unable to disable AMD cpu boost using amd-pstate driver?

Unable to disable AMD cpu boost using amd-pstate driver?

[Qu Wenruo]

Hi Rui,

Thanks for your hard work maintaining amd-pstate driver first.

However it looks like if amd-pstate is used, there is no way to properly
disable the CPU boost (this becomes obvious especially in Linux 6.5, as
amd-pstate is enabled for my 7940HS CPU by default).

Previously using acpi-cppc, there is always a file named "boost" in
/sys/devices/system/cpu/cpufreq, and echo 0 into that file makes my CPU
temp never cross 75 during gaming sessions.


But in Linux 6.5, with amd-pstate, I have to go amd_state=passive to get
that file back, and echoing 0 into that file makes no difference.
I still easily got 90C during the same game.

For now I have to completely disable amd-pstate and rollback to acpi
driver to get a sane temperature.

Is there any proper way to disable the boost using amd-pstate?

Thanks,
Qu

Re: Unable to disable AMD cpu boost using amd-pstate driver?

[Huang Rui]

On Sun, Sep 17, 2023 at 05:52:06PM +0800, Qu Wenruo wrote:
> Hi Rui,
> 
> Thanks for your hard work maintaining amd-pstate driver first.
> 
> However it looks like if amd-pstate is used, there is no way to properly
> disable the CPU boost (this becomes obvious especially in Linux 6.5, as
> amd-pstate is enabled for my 7940HS CPU by default).
> 
> Previously using acpi-cppc, there is always a file named "boost" in
> /sys/devices/system/cpu/cpufreq, and echo 0 into that file makes my CPU
> temp never cross 75 during gaming sessions.
> 
> 
> But in Linux 6.5, with amd-pstate, I have to go amd_state=passive to get
> that file back, and echoing 0 into that file makes no difference.
> I still easily got 90C during the same game.

Have you tried amd_state=active and set balance_power? We can support EPP
and the EPP_INDEX_BALANCE_POWERSAVE maybe fit for your case.

Thanks,
Ray

> 
> For now I have to completely disable amd-pstate and rollback to acpi
> driver to get a sane temperature.
> 
> Is there any proper way to disable the boost using amd-pstate?
> 
> Thanks,
> Qu

Re: Unable to disable AMD cpu boost using amd-pstate driver?

[Qu Wenruo]

On 2023/9/18 17:00, Huang Rui wrote:
> On Sun, Sep 17, 2023 at 05:52:06PM +0800, Qu Wenruo wrote:
>> Hi Rui,
>>
>> Thanks for your hard work maintaining amd-pstate driver first.
>>
>> However it looks like if amd-pstate is used, there is no way to properly
>> disable the CPU boost (this becomes obvious especially in Linux 6.5, as
>> amd-pstate is enabled for my 7940HS CPU by default).
>>
>> Previously using acpi-cppc, there is always a file named "boost" in
>> /sys/devices/system/cpu/cpufreq, and echo 0 into that file makes my CPU
>> temp never cross 75 during gaming sessions.
>>
>>
>> But in Linux 6.5, with amd-pstate, I have to go amd_state=passive to get
>> that file back, and echoing 0 into that file makes no difference.
>> I still easily got 90C during the same game.
>
> Have you tried amd_state=active and set balance_power? We can support EPP
> and the EPP_INDEX_BALANCE_POWERSAVE maybe fit for your case.

Yes, tried both balanced_power and balance_performance, none of them can
reach the old temperature (less than 70C during Armored Core 6 play).

Thanks,
Qu

>
> Thanks,
> Ray
>
>>
>> For now I have to completely disable amd-pstate and rollback to acpi
>> driver to get a sane temperature.
>>
>> Is there any proper way to disable the boost using amd-pstate?
>>
>> Thanks,
>> Qu