Wow, that is pretty good (330 Mbps ~= 40+ MBps), especially through a USB2 port. BTW, is that a read or write speed?
I have a Seagate GoFLEX Home with 3 TB SATA HDD running on an ARMbian (stretch) OS with NFSv4.2 and is connected to my Gigabit LAN as my NAS. I can only get about 36 MBps write speed to my NAS which is way below what my 3 TB SATA HDD can do.