Hello,

I noticed few weeks ago that my download speed doesn't go above 500 mbps while my ISP connection is 1 gbps. I have a fibre converter and my RB1100 AH X2 acts as the PPPOE client.
I tried to change the ports around just to discard any issues with the physical connection, tried to bring the MTU down on PPPOE but that slows things even more, tried a different eth in my computer, no progress on this. And it worked in the past, before upgrading to V7. The speedtest to local ISP server was going above 900 mbps.
I tried direct connection for PPPOE from my computer, it goes to 800-950 mbps download speeds without issues...

The router does handle gigabit transfers well internally (nas to computer is going up to 995 mbps)

Maybe there is something I am missing but I have no clue where to look right now.

Any idea where to start and what to test out is welcomed.

Why if work you update very old device to v7?

What @rextended wanted to write (but somehow failed) is this: it's a well known fact that ROS v7 has lower routing performance than v6. That's due to changes in how linux kernel works and it's not gonna change for the better (not in v7 series for sure). It's also known that PPPoE is a CPU hog ... more than one would expect and on some platforms more than on others.

All in all: sadly what you see is expected and the only way to gain the performance back is to downgrade to v6.

I will try at some point to downgrade. The CPU clogging I am not sure, since during speedtest download, proc goes to 60-65% (up to 480 mbps) and during upload test, it goes to 80% (that goes to 510 mbps, which is a cap from isp)
I do have a cAP here and i can try that since it still has v6 on it.
Otherwise it means I need to plan for an upgrade on this...
Thanks for the input!

Never thought this is the real issue, but it is. The nice part is, it took 2 minutes to downgrade from v7 to v6 and every config was in place. Now I go up to 900 mbps download with the proc going up to 90% so it's fine. Maybe I should plan to go to the newer version this router or even of the new v7 only routers.
Thanks for clearing this up. This can be marked as resolved.

The CPU clogging I am not sure ...

Your router has a multi-core CPU and CPU load displays average for all cores. Certain tasks are single-core and in such case performance can hit the ceiling with average CPU liad way below 100%. Use CPU profiler (with cpu=all) to see how things perform per CPU.