# Optimize CPU power and performance with dynamic voltage and frequency scaling

Dynamic voltage and frequency scaling (DVFS) is a technique used to reduce power consumption of the CPU during active periods. This technique is used to switch the CPU core frequency based on load requirements. DVFS helps in balancing the power, performance, and thermal behavior of the device.

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**Figure : DVFS workflow**

For more information about DVFS, see [index:
kernel/git/torvalds/linux.git](https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/cpu-freq?h=v6.6).

For example, if the available CPU frequencies are 1 GHz, 1.5 GHz, and 2 GHz, and the application must run at 1 GHz, then CPU’s maximum frequency should be 1 GHz. This mechanism optimizes CPU power by ensuring appropriate use of CPU frequency and voltage, thereby supporting high performance.

## Customize CPU frequency

The following table lists the commands used to tune CPU frequency for
balanced power and performance:

Table : Commands to tune CPU frequency

| Commands | Explanation |
| --- | --- |
| cat /sys/devices/system/cpu/cpufreq/policy<x>/scaling_cur_freq<br>    Copy to clipboard | Reads the existing CPU frequency |
| cat /sys/devices/system/cpu/cpufreq/policy<x>/scaling_available_frequencies<br>    Copy to clipboard | Reads the supported frequencies |
| cat /sys/devices/system/cpu/cpufreq/policy<x>/scaling_min_freq<br>    Copy to clipboard | Reads the minimum supported CPU frequency |
| echo <cpu freq in KHz> > /sys/devices/system/cpu/cpufreq/policy<x>/scaling_min_freq<br>    Copy to clipboard | <ul class="simple"><br><li><p>Sets the minimum CPU frequency</p></li><br><li><p>Overwrites the existing CPU minimum frequency</p></li><br><li><p>Sets any frequency from <code class="docutils literal notranslate"><span class="pre">scaling_available_frequencies</span></code></p></li><br></ul> |
| cat /sys/devices/system/cpu/cpufreq/policy<x>/scaling_max_freq<br>    Copy to clipboard | Reads the maximum supported CPU frequency |
| echo <cpu freq in KHz> > /sys/devices/system/cpu/cpufreq/policy<x>/scaling_max_freq<br>    Copy to clipboard | <ul class="simple"><br><li><p>Sets the maximum supported CPU frequency</p></li><br><li><p>Overwrites existing maximum CPU frequency</p></li><br><li><p>Sets any frequency from <code class="docutils literal notranslate"><span class="pre">scaling_available_frequencies</span></code></p></li><br></ul> |

Tab QCS6490/QCS5430
Tab IQ-9075
Tab IQ-8275
Tab IQ-615

Note

`<x>` refers to 0, 4, and 7.

- 0 is for the Silver cluster
- 4 is for the Gold cluster
- 7 is for the Prime cluster
- Unit for frequency is KHz

Note

`<x>` refers to 0 and 4.

- 0 is for Cluster0
- 4 is for Cluster1
- Unit for frequency is KHz

Note

`<x>` refers to 0, 2, and 4.

> 
> 
> - 0 is for the Gold cluster
> - 2 is for the Prime cluster
> - 4 is for the Silver cluster
> - Unit for frequency is KHz

Note

`<x>` refers to 0 and 4.

- 0 is for the Silver cluster
- 4 is for the Gold cluster
- Unit for frequency is KHz

Note

Any modifications made through `SSH` commands revert to their default values upon device reset.

## Next steps

- [Efficient CPU idle power management](https://docs.qualcomm.com/doc/80-70030-30/topic/idlepowermanagement.html#idlepowermanagement)
- [Monitor Suspend Power Management](https://docs.qualcomm.com/doc/80-70030-30/topic/suspend-power-management-state.html#suspend-power-management-state)
- [Efficient wake up latency with power QoS API](https://docs.qualcomm.com/doc/80-70030-30/topic/pmqos.html#pmqos)

Last Published: Jun 22, 2026

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