The router chosen for the setup is the Asus RT-AC66U. This is a current router that features:
- Three external antennas
- Broadcom 802.11ac controller
- Gigabit Ethernet ports (1 x WAN, 4 x LAN)
- 256MB of RAM
- AC1750, 2.4GHz at 450 Mb/s and 5GHz at 1.3 Gb/s
- AiRadar- beamforming technology
The goal was to utilize a router that can match or exceed the capabilities of the wireless AC USB adapters tested, and this Asus model has the go-fast top speed. The latest firmware was used to enhance stability and throughput.
We positioned the RT-AC66U on a cart, which remained in the same location throughout testing. Its antennas were positioned with the center one standing vertically and the two on the side pointing 45-degrees out laterally, as recommended in the owner's manual.
When testing wireless networking hardware, a mobile platform is ideal to facilitate variable distances. We picked Sony's SVS13112FXS laptop, which uses an Intel Core i5-3210M processor at 2.5GHz. It's based on the Ivy Bridge architecture and includes HD Graphics 4000. You also get a 13.3-inch display and plenty of battery life, along with 6GB of DDR3-1333. The operating system is Windows 7 64-bit restored to its factory settings.
During testing, the on-board wireless card was disabled in the BIOS, and all other software other than WirelessMon, IxChariot and TightVNC was disabled. This is done to ensure consistent results, as background processes can affect the results as they consume resources.
Perhaps most important, the Sony notebook has three USB ports, two of which transfer at 3.0 rates. It is important to have these AC-class adapters plugged into a USB 3.0 port capable of 5 Gb/s data rates. USB 2.0 with its theoretical maximum of 480 Mb/s would be a likely performance bottleneck, particularly on the 5GHz band.
For signal strength testing, the laptop was held at its measured distance for 20 to 30 seconds to acquire the signal reading in dB (decibels). In order to level the playing field, the wireless AC USB adapters were plugged directly into the USB 3.0 ports for benchmarking (in other words, the docks or USB extension cords that are provided with some models were not used, since they could give some, but not all, products a signal strength advantage. For those adapters that include extendable antennas, they were positioned upright in a vertical position, and not tuned any further. Our goal was to test the adapter, and not the usefulness of the USB extension cable.
Each of the wireless AC USB adapters was benchmarked with its latest software. While these devices ship with drivers on a CD, they're sometimes outdated. To rectify this, we download any bundled drivers or utilities from the manufacturer's website.
The Sony notebook connects to an ASRock Vision X 471D that plays the server role in our testing. This server features a mobile Haswell processor, Intel's Core i7-4712MQ. It was reviewed previously by Tom's Hardware last year.