PPPoE perfomance issue with APU6

[sherif]

I am facing a bit of a performance issue when using my APU6 directly behind ONT, basically my download max is 250 Mib/s while it should 900+ Mib/s here is summery:

* PPPoE is configured correctly, I can get a session but not my full speed
* I am using APU6 4GB ram https://www.pcengines.ch/apu6b4.htm
* LAN <---> APU6 "OPNSense 25.1.2-amd64" <---> ISP Router "PPPoE" <---> ONT <---> INTERNET and I am getting my full speed 900+ Mib/s to my LAN

* LAN <---> APU6 "OPNSense 25.1.2-amd64" <---> ONT <---> INTERNET and I am getting max 250 Mib/s on my LAN

I tried with compression off, hardware offloading off, same results 250 Mib/s max download speed

and this made me wonder, since when I am behind ISP router, my LAN still getting full bandwidth via the OPNSense box, but not while I am running PPPoE directly, is there some tweaks needs to be done? some kernel parameter? I think PPPoE is capped on the kernel or something

[meyergru]

The GX-412TC in its fastest configuration has 1.4 Ghz and only about 11% of the performance of an N100. Your board limits the CPU to 1 GHz, so it is right at its limit with 250 MBit/s.

[sherif]

The GX-412TC in its fastest configuration has 1.4 Ghz and only about 11% of the performance of an N100. Your board limits the CPU to 1 GHz, so it is right at its limit with 250 MBit/s.

interesting, still the same APU can do 1.0 Gib/s from internet to LAN but not over PPPoE? also CPU load on OPNSense while on PPPoE doesn't hit 60%

Adding to that, the router I tested and worked fine and got me max speed, is ASUS AC87U, which is 10 years old, I know they are custom build for that and ARM, however I still get the full speed and not with the APU.

[pfry]

(Heh. Slow post - behind the curve. But hey...)

Neat device, but amazingly slow. Still, should be faster than most ARM-based consumer cable/wi-fi/etc. routers.

Anyway, lacking data, my first suspicion would be MTU issues. Have you dealt with that (target MTU, TCP MSS, fragmentation, PMTUD, etc.) already?

[meyergru]

We are speaking OpnSense here, which is based in FreeBSD and that does not go well with PPPoE, as it is inherently single-threaded on FreeBSD.

So, if you neither use PPPoE nor OpnSense, you may be fine with 1 GBit/s routing speed with that CPU.

[sherif]

Seems like this is the issue after testing and reading some more threads here, oh well, I guess I am stuck behind this ISP router for a bit then :)