WAN performance for Newifi D2?

Hello.
Does anyone have performed bandwith test on WAN for a Newifi D2 ? Is it capable of 1Gbit/s ?

The Netgear R6220 has a MT7621ST (1 core/2 threads) with 128 MB RAM, and it is able to sustain 650 Mbit/s bandwith. The Newifi D2 has a MT7621AT (2 cores/4 threads) with 512 MB RAM. I assume it is possible to sustain 1Gbit/s, but real test would be appreciated.