APU2, APU3 and APU4 have four 1Ghz CPU cores, pfSense by default uses only 1 core per connection. This limitation still exists, however, a single-core performance has considerably improved. With new BIOS, and settings described below, pfSense can route about 750-800Mbit/s on one connection.
APU2*4 have very performant Intel I210-AT Network Interfaces. These NICs have 4 transmit and four receive queues, being able to work simultaneously on 4 connections. With some fine0tuning, pfSense can take advantage of this and route at 1Gbit when using more than one connection.