Mercusys MR90X Download Speed and SQM Settings Problem

Installing and Using OpenWrt
1

Hello, I recently installed OpenWRT(and after that upgraded to the latest version using LuCI interface) to my router with stock loader method.

If I don't turn on Software or Hardware Offload(Hardware Offload is problematic with upload added latency value in bufferbloat tests so I don't use it, so much added latency like 30-35ms when active) download speed is max 600-650 Mb/s(I have symmetrical FTTH line speeds are 1000/1000).

But if I turn on Software Offload this time SQM's set download and upload speed limits exceeded in speedtest all the time. When I test it with turning off Software Offload and setting limits to 300000 Kb/s, set limits work as expected. But this time download speed can't reach high values.

I have very limited knowledge on Linux and OpenWRT and don't know the reason what causes it. And I saw a test again with MR90X belongs to 2025 and as I saw this person can use SQM as expected.

I have to setup and use VLAN ID to connect my service provider and using Packet Steering as Enabled(not Enabled-All CPUs) all the time.

And ifstatus wan | grep -e l3_device command returned as “l3_device”: “PPOE-WAN” for me. As far as I understand I have to select this as an interface under SQM settings to work, not "eth1.35" device.

2

I now performed another tests. First I installed htop from LuCI after that when I do a speed test CPU 0 is saturated other CPUs not helping and download speed result is in the range of 600-650 Mb/s like that when Offloading disabled at all.

When packet steering set to Enabled-All CPUs this time other cores start helping. This time download speed is in the range 800-850 Mb/s(CPU 0 again most used core, load not spread across to cores in a balanced way)If I enabled SQM with FQ-Codel and Simple QoS settings CPU can’t handle the load again and download speed downed to 650-700 Mb/s range like that. I think there is not a solution for me to use Sofware Offload and SQM at the same time.

Tried irqbalance but recently I uninstalled it. Installed it again but it won’t appear under LuCI’s menu this time. Uninstalling and installing again, rebooting router not working.

Also Enabled-All CPUs packet steering setting causes bad added latency when using Sofware Offload, Enabled setting fixes it.

3

(Your PPPoE)

4

I am using PPPoE.

5

We know, and it doesn't spread across the cores.