CPU Frequency Scaling

Notices and Disclaimers
Revision History
Introduction
- Related References
Initial Checklist
Baseline Performance Measurements and Tuning Methodology
- Network Performance Benchmarks
  - iPerf2
  - iPerf3
  - netperf
- Tuning Methodology
Tuning i40e Driver Settings
Platform Tuning (i40e Non-Specific)
Adapter Bonding
Performance Troubleshooting
Recommendations for Common Performance Scenarios
- IP Forwarding
- Low Latency

CPU frequency scaling (or CPU speed scaling) is a Linux power management technique in which the system clock speed is adjusted on the fly to save power and heat. Just like C-states, this can cause unwanted latency on network connections.

The cpupower tool can also be used to check and modify CPU performance defaults and limits:

Check: cpupower monitor or

Set CPUs to performance mode: cpupower frequency-set -g performance

Note:Modifications to CPU frequency limits can have an impact to many workloads and might disable other features, such as CPU turbo mode.

To disable CPU frequency scaling, disable the CPU power service by the following commands:

systemctl stop cpupower.service systemctl disable cpupower.service

Additional Power Management Guidance

PCIe Power Management Additional Power Management Guidance

Intel® Ethernet 700 Series

Linux Performance Tuning Guide

​CPU Frequency Scaling

CPU Frequency Scaling