I have a usb wifi adapter with Ralink RT5572 (300Mbit/s) chipset running on PineA64+, connected to a usb 2.0 port. It runs flawless except of the bandwith, what is ~45Mbit/s on 2,4GHz, 20MHz channel with, N mode. Tested on my Lenovo with 2x2 Intel N-2200 with "iperf", 4m away, clear view, but approx. 30 other access points around. 5GHz is not an option, my clients only have 2,4GHz wifi.The PineA64 usb should not be the bottleneck, on my usb lan adapter I get 270-300Mbit/s on usb 2.0.
What do you think about the weak performance?