The 420E's inside photo shows the QCA7500 at lower center. That's an AR8035 Gigabit Ethernet PHY right above it. There is no separate analog front end (AFE) device; that function is built into the QCA7500. This board is plugged into another board below it that has the wall plug and mostly passive components.
TRENDnet TPL-420E inside
The 420E didn't get very hot during testing, despite its lack of any heatsinks or thermal pads. I guess TRENDnet figured the large and plentiful side ventilation holes would keep it cool enough. Note there are no vent slots on top of the device.
TRENDnet includes a Power Packet Utility on the CD packed in the 420E2K's box. You can also download it from the product's support page. It requires WinPcap 4.1.3, which will also be installed if it isn't already. The screenshot below shows the Utility, which doesn't expose the incomprehensible QoS controls some other powerline utilities do.
The screenshot was taken with both adapters plugged into the same power strip, so the 930 Mbps (link?) rate is as good as it got in my testing.
Power Packet Utility
You can also use the utility to set the encryption key if you don't want to use the pushbutton method.
I tested the TPL-420E using our standard powerline test procedure, with all results entered into the Powerline Performance Charts. We now have two AV2-M1000 class devices to compare, so the charts include ZyXEL's PLA5405.
The Downlink Throughput plot below shows the TPL-420E having the highest throughput in the best-case same-outlet Location A and worst-case Location E. The 420E's 433 Mbps is 30% higher than the ZyXEL's throughput. But products are even at the medium-range location C test.
Downlink throughput comparison
Uplink results show the 420E with a 13% edge at Location A and dropping to about half that in the other two locations.
Uplink throughput comparison
The simultaneous up /downlink IxChariot plot for the TPL-420E at Location A shows higher average uplink throughput, but with both trading positions throughout the one minute test. Note throughput totals just over 480 Mbps, a bit better than the ZyXEL's 419 Mbps in the same test.