Hy,
I have a Tinkerboard with armbian ( debian jessie).
When I put behind my fiber router, and i do a speed test i have :
With iperf3 ==> download : 980M and upload : 240M
with speedtest-cli ==> More or less Results.
I wanted to conenct my Asus's card behind the ONT(Optical Termination Boxes) i can connect with pppoe or dhcp.
And in pppoe or dhcp my speed test show this :
With iperf3 ==> download : 110M and upl