Re: Strange Chelsio performance (T6225-CR)

From: Sad Clouds <cryintothebluesky_at_gmail.com>
Date: Tue, 02 Dec 2025 15:47:43 UTC 
On Mon, 1 Dec 2025 13:01:28 -0500
mike tancsa <mike@sentex.net> wrote:

> TL;DR. I can get 10G coming in and out on port 0, Port 1 can only take 
> traffic at ~ 2.5 Gb/s incoming, but can send out a full 10G.

I've seen asymmetric throughput performance similar to what you report
with Intel X520-SR2 and when using device passthrough in Bhyve VMs
running FreeBSD-14.3.

Configuring the switch and network interfaces to use MTU of 9000 bytes
resolved the issue for me. After this, the send and receive throughput
performance has remained stable at around 9 Gb/sec.