Maximum Wireless Throughput
Since throughput vs. attenuation plots are now done with a 2x2 STA, we use the Ixia Veriwave that can emulate up to 4x4 ac devices to test maximum throughput. The results posted are an average of 10 one minute test runs. This benchmark is fully described in the Revision 9 test process description. We're again comparing the AD7200 with the same other 4x4 products. Keep in mind we use 40 MHz bandwidth in 2.4 GHz for this test.
2.4 GHz results show the AD7200 tied with the NETGEAR R7800 at 425 Mbps for downlink throughput. The two products move further apart for uplink, but both end up higher than the ASUS and Archer C3150.
Maximum Wireless Throughput comparison - 2.4 GHz
The AD7200 and NETGEAR continue to rank #1 and 2 in the 5 GHz maximum comparison, trading places between downlink and uplink tests. It's worth noting both products were able to link at their maximum MCS rates for both bands. The ASUS would link only at MCS7 (1300 Mbps) and the Archer C3150 only at MCS8 (1560 Mbps) in their 5 GHz tests.
Maximum Wireless Throughput comparison - 5 GHz
60 GHz (802.11ad) Performance
Devices supporting 802.11ad are even harder to find than those supporting MU-MIMO. Fortunately, TP-LINK sent one of the few devices that does--an Acer TravelMate TMP446-M-77QP notebook. It's part of Acer's TravelMate P4 line, sporting a 2.4 GHz Intel Core i7-5500U processor, 8 GB of DDR3 RAM and a Qualcomm Atheros "Sparrow" 802.11ad adapter (at least that's how it is identified in Windows properties).
Getting the AD7200 and the Acer notebook linked up using 802.11ad was just like setting up a Wi-Fi connection. TP-LINK defaults the AD7200 to a unique SSID for each band, so all three appeared when the Wi-Fi network icon in the Windows Notification area is clicked on. Entering the WPA2 key when prompted set the connection right up.
I was not surprised to not see the advertised 4.6 Gbps maximum link rate for the connection, even with notebook and router four feet apart. The most I saw was 3.8 Gbps during a drag-and-drop transfer, shown in the screenshot below. This was transferring the same ripped-DVD folder used for all filecopy testing, which contains a combination of 1 GB VOB and other smaller files.
802.11ad in action
The 101 MB/s shown in the file transfer window might be a surprise, given the 3.8 Gbps link rate. But it turns out the internal architecture of the AD7200 limits any single connection to 1 Gbps (125 MB/s). Since the 11ad radio connects via PCI-e, the bandwidth bottleneck isn't there. An obvious pinch point is that link aggregation is not supported on any of the switch ports.
To work around this limitation, TP-LINK's reviewer's guide suggested testing 11ad throughput using a computer connected to the router WAN port, another connected to a LAN port and one 5 GHz wireless client. I decided to start with two Ethernet connections to the AD7200's LAN ports and see where that took me.
I used the Veriwave test set WBE1604 Ethernet WaveBlade, which is capable of supporting full-duplex Gigabit Ethernet connections simultaneously on all its four ports. Two ports were set to send TCP/IP traffic at full line rate, through the AD7200's LAN ports. On the wireless side, I installed Veriwave's WaveAgent app on the Acer laptop, running multiple instances to link up with the separate traffic streams sent from the Ethernet blade. The AD7200 and Acer laptop were about 4 feet apart as shown in the photo below, taken in the luxurious SmallNetBuilder back test lab.
802.11ad test setup
The plot below shows total TCP/IP throughput measured with the combinations of transmit (TX) and receive (RX) connections shown. Transmit flow is from Ethernet to Wireless, receive is the opposite.
60 GHz throughput test - Total Throughput
- Unidirectional throughput is a solid 1 Gbps using a single connection, receive or transmit
- Best case throughput of around 1.5 Gbps is obtained using the full-duplex capability of a single Gigabit Ethernet connection.
- Worst throughput occurs with two transmit connections
The plot below shows the individual connections.
60 GHz throughput test - Component Throughput
I also ran a quick check, adding a third Ethernet channel to the router's WAN port. Total throughput was actually a bit lower, around 1.3 Gbps. If the WAN port truly had a separate Gigabit path to the 11ad radio, I would have expected to see total throughput rise to at least 2 Gbps.
60 GHz throughput test - Total Throughput - 1 WAN, 2 LAN connections
The takeaway is that despite the 4.6 Gbps link rate bandied about for the AD7200's 802.11ad connection, you'll be getting only the equivalent of a Gigabit Ethernet connection.
How far will that connection reach? Not very. Putting myself between the router and and Acer laptop dropped throughput to close enough to zero, as did putting one sheetrock wall between the laptop and router. I was surprised to be able to walk the laptop out of the room and down the hallway a few feet without the connection dropping. But moving a few feet more did the deed.