Intel® Ethernet Adapters and Devices User Guide

ID 705831
Date 06/24/2024
Public
Document Table of Contents

Low Latency Interrupts

Low Latency Interrupts (LLI) enable the network device to bypass the configured interrupt moderation scheme based on the type of data being received. LLI configures which arriving TCP packets trigger an immediate interrupt, enabling the system to handle the packet more quickly. Reduced data latency enables some applications to gain faster access to network data.

Note:

When LLI is enabled, system CPU utilization may increase.

LLI can be used for data packets that contain a TCP PSH flag in the header or for specified TCP ports:

  • Packets with TCP PSH Flag: Any incoming packet with the TCP PSH flag will trigger an immediate interrupt. The PSH flag is set by the sending device.

  • TCP Ports: Every packet received on the specified ports will trigger an immediate interrupt. Up to eight ports may be specified.

To change this setting in Intel PROSet:

This setting is found on the Advanced tab of the device’s Device Manager property sheet or in the Adapter Settings panel in Intel PROSet ACU.

To change this setting in Windows PowerShell, use the Set-IntelNetAdapterSetting cmdlet. For example:

Set-IntelNetAdapterSetting -Name "<adapter_name>" -DisplayName "Low Latency
Interrupts" -DisplayValue "Port-Based"

Possible values for this setting are:

  • Disable

  • PSH Flag-Based

  • Port-Based