# What type of control is used to manage the different clock configurations (nvpmodel)?

**URL:** <https://forums.developer.nvidia.com/t/what-type-of-control-is-used-to-manage-the-different-clock-configurations-nvpmodel/158359>\
**Category:** Jetson TX2\
**Tags:** kernel\
**Created:** [October 30, 2020, 12:53pm UTC](https://forums.developer.nvidia.com/t/what-type-of-control-is-used-to-manage-the-different-clock-configurations-nvpmodel/158359 "2020-10-30T12:53:03Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![Aizzaac](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@Aizzaac](https://forums.developer.nvidia.com/u/Aizzaac)\
**Post date:** [October 30, 2020, 12:53pm UTC](https://forums.developer.nvidia.com/t/what-type-of-control-is-used-to-manage-the-different-clock-configurations-nvpmodel/158359/1 "2020-10-30T12:53:04Z")

</div>

Hi

The TX2 has many clock configurations: MAXN, MAXP, MAXQ, the Jetson\_clocks. I am wondering what type of algorithm/control is used to manage frequency?

Is it reactive or proactive?  
Reactive: when a trip point is reached, the frequency will diminish.  
Proactive: it tries to predict a future temperature or workload and according to that diminish or augment frequency.

Thank you

---

<div class="post-metadata">

**Author:** ![JerryChang](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/jerrychang/32/14043_2.png) [@JerryChang](https://forums.developer.nvidia.com/u/JerryChang)\
**Post date:** [November 2, 2020, 3:40am UTC](https://forums.developer.nvidia.com/t/what-type-of-control-is-used-to-manage-the-different-clock-configurations-nvpmodel/158359/3 "2020-11-02T03:40:15Z")

</div>

hello Aizzaac,

you may refer to developer guide,  
please check [Supported Modes and Power Efficiency](https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3243/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fpower_management_tx2_32.html%23wwpID0E01N0HA) for NVPModel clock configurations.  
please refer to [Maximizing Jetson TX2 Performance](https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3243/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2Fpower_management_tx2_32.html%23wwpID0E0PB0HA) for the details of Jetson\_clcocks.

in short,  
nvpmodel has configuration to set the maximum clock frequency of each power modes. you may have variable clock rates; Jetson\_clocks force the clock frequency to current support maximum frequency, you **won’t** see variable clock rates.  
there’s [tegrastats utility](https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3243/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2FAppendixTegraStats.html%23) you may used for checking memory usage and processor usage.  
thanks

---

<div class="post-metadata">

**Author:** ![Aizzaac](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@Aizzaac](https://forums.developer.nvidia.com/u/Aizzaac)\
**Post date:** [November 2, 2020, 12:37pm UTC](https://forums.developer.nvidia.com/t/what-type-of-control-is-used-to-manage-the-different-clock-configurations-nvpmodel/158359/4 "2020-11-02T12:37:52Z")

</div>

okey, about the `variable clock rates` what determines it has to change or not? what type of control there is? is it a PID control? like the one that comes within the linux kernel? or something else?

---

<div class="post-metadata">

**Author:** ![JerryChang](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/jerrychang/32/14043_2.png) [@JerryChang](https://forums.developer.nvidia.com/u/JerryChang)\
**Post date:** [November 3, 2020, 12:38am UTC](https://forums.developer.nvidia.com/t/what-type-of-control-is-used-to-manage-the-different-clock-configurations-nvpmodel/158359/5 "2020-11-03T00:38:02Z")

</div>

hello Aizzaac,

there’s [tegrastats utility](https://docs.nvidia.com/jetson/archives/l4t-archived/l4t-3243/index.html#page/Tegra%2520Linux%2520Driver%2520Package%2520Development%2520Guide%2FAppendixTegraStats.html%23) you may used for monitor memory usage and processor usage.

---

<div class="post-metadata">

**Author:** ![nadeemm](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/nadeemm/32/367020_2.png) [@nadeemm](https://forums.developer.nvidia.com/u/nadeemm)\
**Post date:** [October 18, 2021, 6:16pm UTC](https://forums.developer.nvidia.com/t/what-type-of-control-is-used-to-manage-the-different-clock-configurations-nvpmodel/158359/7 "2021-10-18T18:16:32Z")

</div>

Closed on October 18, 2021, 6:16pm UTC