Review of Asus USB-AC51

[fakemanhk]

Recently came across this Asus USB-AC51 while travelling to Taiwan, found it cheap so I bought it.

I tested it with OpenWrt 23.05.2, with NanoPi R2S (USB 2.0), the setup is pretty easy, simply load the kmod-mt76x0u module and OpenWrt can detect and use it without problem

I tested with a phone + ChromeOS laptop, OpenWrt in AP mode so no any routing involved. When the phone is getting very close to it, I can get as much as 220Mbps transfer speed which isn't really bad, but laptop placed roughly 50cm above with a wooden table in between is showing more obvious signal degrade, the displayed connectivity speed can't reach 433, mostly fluctuating between 325-390Mbps, speed test results ranging from 80Mbps~130Mbps. I guess this is due to the form factor of the dongle, and I noticed that even I am walking away from my room (7m away, with wall in between) my phone can continue to get 80-110Mbps transfer speed, so I would say this can be used for travel AP in hotel.

Power consumption: I plugged USB-C power meter to monitor the whole setup, during speed test current consumption jumped up for ~140mA when running full speed, no significant temperature rise observed (by touching only)

Side note: At the beginning I was trying to use it with 1st gen Raspberry Pi 1B but not sure if it's due to USB NIC onboard + slow processor, I know the onboard USB NIC is only 100M but my speedtest result was no more than 70Mbps, I will try to repeat it with my Raspberry Pi 3B (also USB 100M NIC onboard) later to see how it goes.