Intel NIC latency

I run a Manjaro on a machine with an RT kernel for LinuxCNC. This isn’t the ideal environment but it works well once everything is built. I use an ethernet based motion controller. I’ve re-installed this system various times for various reasons and I always get it working but I noticed some instructions on the LinuxCNC forum pertaining to running an Intel NIC to edit /etc/network/interfaces and add “hardware−irq−coalesce−rx−usecs 0” to the interface. Manjaro has a different setup, is there an equivalent to this?

Probably with ethtool (ethtool(8) — Arch manual pages) and systemd service to make it persistent.

Or you can try throwing it in NetworkManager’s (or whatever you are using) network conf file.

The easiest way is probably with ethtool manually or a NM-dispatcher script the start the ethtool command. A systemd service might also work.

You can check the current values for coalesce with

sudo ethtool -c eth0

assuming the device is called eth0 This is might not be the case on your system.

You can set rx−usecs 0 with with the -C option (capital C).

sudo ethtool -C eth0 rx-usecs 0