Windows power plan settings explorer utility

Discussion in 'Operating Systems' started by mbk1969, Aug 3, 2017.

  1. Donduck

    Donduck Master Guru

    Messages:
    383
    Likes Received:
    26
    GPU:
    Radeon RX Vega 7
    Allow Throttle States (3b04d4fd-1cc7-4f23-ab1c-d1337819c4bb) seems to have a bug: when throttle states is disabled, the actual lowest performance could higher than the lowest P-state. It could be reproduced with a reboot or startup. Bus frequency reported by ThrottleStop also varies from 94MHz to 101MHz on my laptop, where normal speed should be 99MHz.
    Therefore I give up the approach of tuning QoS at lowest P-state, instead limiting them at 1GHz, which is sufficient.
     
  2. Donduck

    Donduck Master Guru

    Messages:
    383
    Likes Received:
    26
    GPU:
    Radeon RX Vega 7
    We can now guess how Windows 11 24H2's "hetero containment policy" works:
    when efficiency containment threshold is not exceeded, schedule to E-cores only;
    what hybrid and no containment means require further tests. One of them must mean all cores are available for scheduling.
    [​IMG]
    [​IMG]
     
  3. EdKiefer

    EdKiefer Ancient Guru

    Messages:
    3,163
    Likes Received:
    403
    GPU:
    ASUS TUF 3060ti
    https://www.techpowerup.com/review/intel-lunar-lake-technical-deep-dive/4.html
    "Intel made generational improvements to Thread Director, its hardware component that ensures the right CPU processing load is allocated to the right kind of CPU core, and they migrate correctly. Intel has improved the accuracy and aptitude of its algorithms, and gave the algorithm finer granularity.
    This version of Thread Director also introduces OS containment zones, which lets users tag software to be contained to the P-cores, the E-core cluster, or be zoneless. Lunar Lake uses a dynamic scheduling policy that runs everything on E-cores, and graduates them to P-cores based on processing demand."

    Another
    "These include an Efficiency Zone which schedules the work to the E-Cores, the Hybrid/Compute Zone which schedules the work the the P-Cores, and a "Zoneless" mode which schedules the work across both P-Cores and E-Cores. These Zones constrain the workloads to only those cores and keep the rest of the compute tile cores either parked or idle."
    https://wccftech.com/intel-lunar-la...skymont-double-digit-ipc-new-thread-director/

    So according to the above info zoneless has no containment, all cores are used.
     
    Last edited: Jun 4, 2024
  4. Donduck

    Donduck Master Guru

    Messages:
    383
    Likes Received:
    26
    GPU:
    Radeon RX Vega 7
    So the scheduling order would be E-cores only, P-cores only, all cores.
     
    EdKiefer likes this.

  5. Donduck

    Donduck Master Guru

    Messages:
    383
    Likes Received:
    26
    GPU:
    Radeon RX Vega 7
    Theoretically the new scheduling behavior could be used by any heterogenous processors, but the slide says containment zones are based on an initialization table by thread director, too sad this is a lunar lake exclusive feature.
     
  6. Donduck

    Donduck Master Guru

    Messages:
    383
    Likes Received:
    26
    GPU:
    Radeon RX Vega 7
    I have finally confirmed how those latency sensitivity hint settings work:
    Mouse button up event means not touchpad click;
    Touch gesture start and stop means not touchpad touching;
    Keyboard enter key down means only the "Enter" key can trigger such event, not other keystrokes.
    Windows 11 has added Latency sensitivity hint processor energy performance preference, but I think there is no need to do further tests.
     
  7. Donduck

    Donduck Master Guru

    Messages:
    383
    Likes Received:
    26
    GPU:
    Radeon RX Vega 7
    Reading Windows 7 document and find definition of the option "ideal" of performance increase/decrease policy:
    And reading about the schedutil governor of Linux:
    Note that the 1.25 coefficient is not tunable in Linux, Android can tune it with a parameter called hispeed_load.

    Windows had schedutil mechanism 10 years before Linux (Windows Vista in 2006 vs Linux kernel 4.7 in 2016), with more tunable options; and when Linux had schedutil, Windows was already having the new CPPC frequency scaling.
     
    Last edited: Jun 15, 2024
  8. Harvest

    Harvest New Member

    Messages:
    1
    Likes Received:
    0
    GPU:
    2060
    .
     
    Last edited: Jun 17, 2024
  9. mbk1969

    mbk1969 Ancient Guru

    Messages:
    16,011
    Likes Received:
    13,933
    GPU:
    GF RTX 4070
    I just noticed in HWiNFO that some CPU cores go to 900 MHz. I am sure lowest P-state is 1200 MHz.
    Code:
    Processor 11 in group 0 exposes the following power management capabilities:
    
    Idle state type: ACPI Idle (C) States (2 state(s))
    
    Performance state type: ACPI Collaborative Processor Performance Control
    Nominal Frequency (MHz): 3504
    Maximum performance percentage: 131
    Minimum performance percentage: 34
    Minimum throttle percentage: 20
    
    I launched perfmon and see that indeed some cores dive to 26 % state which is the zone of T-states. I launched PSE and see that T-states are not allowed in power plan settings. Strange...
     
  10. Donduck

    Donduck Master Guru

    Messages:
    383
    Likes Received:
    26
    GPU:
    Radeon RX Vega 7
    Try play with the MSR:
    address 0x1FC

    bit 19:
    Disable Energy Efficiency Optimization (R/W) Setting this bit disables the P-States energy efficiency optimization. Default value is 0. Disable/enable the energy efficiency optimization in PState legacy mode (when IA32_PM_ENABLE[HWP_ENABLE] = 0), has an effect only in the turbo range or into PERF_MIN_CTL value if it is not zero set. In HWP mode (IA32_PM_ENABLE[HWP_ENABLE] == 1), has an effect between the OS desired or OS maximize to the OS minimize performance setting.

    bit 20:
    Disable Race to Halt Optimization (R/W) Setting this bit disables the Race to Halt optimization and avoids this optimization limitation to execute below the most efficient frequency ratio. Default value is 0 for processors that support Race to Halt optimization.

    Bit 19 significantly affect throttle state bahaviour, but I do not see any power consumption benefit from disabling this feature.

    PS: C1E seems to be a SpeedStep thing from the document.
     
    Last edited: Jul 4, 2024

  11. SENT1R

    SENT1R Active Member

    Messages:
    54
    Likes Received:
    19
    GPU:
    MSI 6750 XT TRIO
    How do I disable C-States levels in this program?
     
  12. mbk1969

    mbk1969 Ancient Guru

    Messages:
    16,011
    Likes Received:
    13,933
    GPU:
    GF RTX 4070
    You can disable C-states completely, or you can try to tune the promotion/demotion of C-states by % of CPU busy.
    You can`t disable C-states levels in power plan settings. You can do that in BIOS (UEFI).
     

Share This Page