Intel® Ethernet 800 Series

Linux Performance Tuning Guide

ID Date Version Classification
636781 10/23/2023 Public
Document Table of Contents

​Flow Control

Layer 2 flow control can impact TCP performance considerably and is disabled by default in the driver. This is the recommended setting for most workloads. A potential exception is very bursty traffic, where the bursts are not long in duration, which might result is packet drops.

  • ​​To enable flow control: ethtool -A ethX rx on tx on
  • ​​To disable flow control: ethtool -A ethX rx off tx off
Note:​You must have flow control configured on a capable link partner to successfully enable flow control on the adapter. Note:​Data Center Bridging (DCB) and Priority Flow Control (PFC) are other methods of controlling packet rates and can impact performance. However, these are outside of the scope of this document.