​CPU Package C-State Control

Disabling CPU Package C6 state entry can improve network performance. However, this increases power usage.

Some methods to check and control C-state entry within your OS are:

• ​​Use the cpupower command to check and disable CPU C6 state:

Check:

Disable C6:

OR

Disable C-States:

Notes:

1. Disable C-states on the CPU if the server has 4th Gen Intel® Xeon® Scalable Processor(s). When Hyper Threading is enabled or disabled, disabling idle states (-D0) prevents cores from entering low-power states during idle periods and also reduces the latency for the CPU to transition between idle and active states.
2. The power management of the Intel 4th Gen Intel® Xeon® Scalable Processor is extremely aggressive. To avoid cores from entering low-power states, try reducing the number of cores in use to keep them awake for longer (ethtool -L <ethX> combined <numcores>)

Enable C6:

Enable C-States:

• ​​Another method is to utilize the tuned tool (included with many Linux distributions) to set a performance profile. These profiles modify several OS settings that can affect performance across many applications. It has been found that the network-throughput profile provides improvement to most workloads.

Check:

Set:

Note:tuned service must be running for above commands. To check/restart tuned: systemctl status tuned systemctl restart tuned