What is the reason for the low speed in Mikrotik?

Question

Mikrotik

Good afternoon.
I have a RouterBOARD 941-2nD router.
When connected via a wire or wireless network, the speed in one stream is not higher than 18-30 megabits / s. In several streams, the speed is normal.

Without a router - 80 megabits / s both in one stream and in several.
What could be the reason?
There are no queues or restrictions in the settings.
CPU ~ 50%

That is, the problem is in single-threaded mode.

Answer 1

Can I export Mikrotik configuration?

Answer 2

In general, it's strange ...
What's in the firewall?
Fasttrack disabled?
What does the speedtest say? In one stream...?