Asus ZenWiFi AX (XT8) Tri-Band Mesh System Review

In the time between the announcement of Wi-Fi 6 (IEEE 802.11ax) standards in October 2018 and now, the market have seen a variety of Wi-Fi 6 capable devices released by various vendors ranging from networking devices to smartphones. If you like to know more about Wi-Fi 6 and the benefits it brings, here is an explainer.

Even though Wi-Fi 6 is more secure and performant than Wi-Fi 5, wave 2 Wi-Fi 5 routers or mesh systems remain a good choice for majority of households if they have a small/medium-sized home with a few devices.

Background

Personally, I was using the D-Link WiFi mesh system, COVR-2202, for the past one year. During the early stages of the work-from-home arrangement because of COVID-19 pandemic, I could participate in video/conference calls with minimal issues. You can find a review of this mesh system that I wrote previously here.

However, the mesh system started having performance and stability issues this earlier this month. It was due to a change in my home network environment. The number of networked devices had grown to 24 devices—nearly half of these are smart home devices. My video calls started suffering from connectivity issues with stuttering videos, and sometimes, I could not hear what my colleagues were saying. Even the smart home devices are suffering from connectivity issues.

Therefore, my next networking gear purchase had to fulfil the following conditions:

  1. Is a mesh system
  2. More control on the Wi-Fi configurations
  3. Future-proof for WiFi 6
  4. More powerful hardware that provide good WiFi coverage and stable connection for many devices

When I was looking for a new WiFi 6 mesh system, I narrowed my choice down to Netgear Orbi RBK852 (3 pack) and Asus ZenWiFi. I did not consider the other brands as they do not have a good track record when it comes to keeping their products up to date. Furthermore, their product designs leave much to be desired.

In the end, I went with the ASUS ZenWiFi AX6600 (XT8) as I have used an Asus router (RT-AC68U) before and my experience with that then was good. The RT-AC68U was stable in terms of its performance and connectivity even after going for three or four months without a system reboot. And Asus routers do come with a lot more configuration options in their web interface when compared to the others.

Hardware

The Asus ZenWiFi comes in two colours: black and white. For me, I went with the black version because it fit better with the overall house theme. In terms of pricing, the hardware itself cost SG$775 from Challenger.

You may be wondering why it cost that much. Unlike other mesh systems, the ZenWiFi mesh system consist of two full-featured wireless routers that can be configured to run independently or operate together in a mesh system through ASUS AiMmesh technology.

In terms of design, it is minimalistic and does not stand out. It comes with a single LED light at the front that indicates the state of the router. It has specially designed vents on the sides to help keep the routers cool.

Physical appearance aside, we shall take a look at the specifications.

Below is the specification for each router:

  1. 1.5 GHz quad-core processor
  2. 512 MB RAM
  3. 256 MB flash storage
  4. Tri-band: 2×2 2.4 GHz, 2×2 5 GHz-1, 4×4 5 GHz-2
  5. 6 internal antennas positioned to give maximum WiFi coverage
  6. 3x gigabit Ethernet LAN port and 1x 2.5G WAN port. The latter can be used as a LAN port on the satellite node

From the above, we can see that the Asus ZenWiFi mesh system is a tri-band mesh system.

With that, the 2.4GHz and 5GHz Wi-Fi band are freed up for our devices to connect to while a separate 5 GHz Wi-Fi band is used for the wireless backhaul. This wireless backhaul is used by the satellite node and the main router to communicate with each other.

From the product’s official site, the device is capable of the following:

  • 802.11a: 6,9,12,18,24,36,48,54 Mbps
  • 802.11b: 1, 2, 5.5, 11 Mbps
  • 802.11g: 6,9,12,18,24,36,48,54 Mbps
  • 802.11n: up to 300 Mbps
  • 802.11ac (5GHZ-1):up to 867 Mbps
  • 802.11ac (5GHZ-2):up to 3466 Mbps
  • 802.11ax (2.4GHz): up to 574 Mbps
  • 802.11ax (5GHZ-1):up to 1201 Mbps
  • 802.11ax (5GHZ-2):up to 4804 Mbps

However, the above are just theoretical numbers that is hardly achievable due to various factors such as neighbouring Wi-Fi interference, physical obstacles like walls and the distance between the mesh system and our devices.

If we use the 5GHZ-2 band as an example, the speed indicated is achievable if the mesh system is able to utilise all 4 streams to send and receive data using the 160 MHz channel width.

However, there is only one channel available for 160 MHz and that is assuming there are no interference from your neighbours and you can use DFS channels. The latter is important to note as eight 20 MHz channels will need to be combined into one channel. And in Singapore, most of those 20 MHz channels are DFS channels and their availability is dependent on whether you are living near a radar station. Furthermore, if you are living in a HDB apartment with a lot of neighbours, the mesh system will find itself dealing with a lot of interference and likely to fall back to using the 80 MHz channel width. At least when using 80 MHz, there are 5 channels to choose from.

But all the above is just theory. We will need to test the mesh system in the real.

Performance

As described earlier, the mesh system comes with a dedicated wireless backhaul. However, the use of the wireless backhaul would mean that you will not be able to get higher WiFi speeds since the total amount of available wireless bandwidth will be divided equally between the backhaul and other connected devices.

If you do need a higher backhaul speed, ethernet backhaul connection for the mesh node to the main router is supported and available. With this, the WiFi 5 GHz-2 band can be freed up for use by devices.

For me, I decided to go with the wireless backhaul due to two considerations:

  1. The mesh node should try and stay as close to the center of the house as possible since the main router is at the corner of the house in the living room. It is so the remaining half of the house could get WiFi with no dead spot.
  2. Remove the need to route additional ethernet cables from the main router to the node.

After spending time tweaking the configurations, I was able to achieve a decent WiFi speed on the 5 GHz-1 band with my MacBook Pro connected to the satellite node. In this case, there was a direct line of sight between the node and the MacBook.

This is the result of the first test.

Other than the WiFi performance for devices with direct line of sight to the router, it is equally important to have good performance for devices that are behind walls or further away from the nodes.

Another test of the connection speed was conducted. This time it is between my iPhone X and the satellite node while I’m in the laundry area of the house, which is the furthest possible point from the satellite node with at least one wall between.

The phone being able to achieve 101mbps in download speed is nothing short of impressive. We need to keep in mind that there are 23 other devices connected to the mesh system and at least one wall sitting between the phone and the satellite node.

To achieve the above speeds, the following configurations were used for the mesh system.

Basic Configurations

2.4 GHz and 5 GHz-1 front-haul Wi-Fi configuration

5 GHz-2 dedicated wireless backhaul configuration.

Advanced Configurations

5 GHz-1 advanced configurations

5 GHz-2 advanced configurations

In order to achieve higher speeds, a device ideally should establish a WiFi connection using the 80 MHz channel width. In my case, my laptop was able to do that.

However, there is no guarantee your devices will be able to get that since it is dependent on whether the Wi-Fi hardware supports higher bandwidths and negotiate with the router for that. In addition, there is also a higher chance of interference due to channel overlap with your neighbour’s WiFi routers since a wider channel is nothing more than the combination of multiple smaller channels, which can cause connectivity or performance issues.

Over the following one week since getting the mesh system, I made more changes to the advanced configurations.

5 GHz-1 advanced configurations

5 GHz-2 advanced configurations

A second internet speed test was done using the updated configuration from my 2018 15 inch MacBook Pro.

Stability

Compared to the D-Link Covr-2202 mesh system, the Asus ZenWiFi has been stable for 8 days now since the last restart due to configuration changes. Devices remain connected to the mesh system and could access the internet without any issues. Again, we need to keep in mind that there is a constant 22 to 24 devices connected.

Furthermore, I did not find myself having to deal with stuttering video and audio during Microsoft Team/Google Meet/Zoom calls. The longest call that I have can go up to one hour and a half.

However, I could not say the same for the Covr-2202. When I first got it to replace the Asus RT68U, my devices would not be able to access the internet from time to time. An investigation revealed that the routers would either drop connections or refuse to issue IP addresses. This tend to crop up after a week of use for reasons that remain unknown to me. So, to prevent the dropped connections from happening again, I scheduled a weekly restart that happens at the stroke of midnight on Monday.

Wi-Fi Coverage

Asus states that ZenWiFi mesh system is able to cover up to 5500 square feet (or 6 rooms) when using both routers in mesh mode while single ZenWiFi router is able to cover up to 2750 square feet or 4 rooms. With that in mind, single router is enough for majority of households in Singapore since we live in HDB apartments, which have an average size of 1027 square feet.

However, it did not take into account that there are a lot of concrete walls and solid objects such as cabinets in a HDB apartment. Solid objects such as concrete walls can block or reduce the strength of WiFi signals causing connectivity issues, low speeds and high latencies. In this case, the 5 GHz band is more severely affected than the 2.4 GHz band.

During my unscientific tests, the ZenWiFi did surprise me. My phone was able to stay connected and achieve about 30mbps of download speed even when I am standing in the kitchen, near the common toilet. At least two concrete walls stand between my phone and the mesh node.

The next test was done with me walking around the house. My phone was able to stay connected to WiFi and I was able to stream video without any visible issues.

Furthermore, I lived on the eight floor. When I was on the first floor, my phone was still able to secure a connection to the mesh system. I suspect it is due to the fact that the main router of the mesh system is placed near the window in the living room. Nonetheless, I find this impressive since I can continue to use my WiFi even when I’m outside my house.

Conclusion

The Asus ZenWiFi AX6600 (XT8) is expensive but not as expensive as the Netgear Orbi RBK852 WiFi 6 mesh system, which cost an additional SG$200 or SG$300 depending on where you get it.

In terms of hardware specification, the Asus ZenWiFi comes with only 6 internal antennas compared to the 8 on the Netgear Orbi RBK852 WiFi 6 mesh system. More antennas meant that the router would be able to provide more bandwidth for devices, which translates to better performance. The Asus model also comes with a slower quad-core processor and 1 less gigabit LAN port.

But for that price, what you are getting is two Wi-Fi 6 capable, fully-featured wireless routers that you can choose to give one away to your family or friends. The AsusWRT, which is the operating system of all Asus-made routers, tends to be more stable from my personal experience and comes with more configuration options. The latter can be a consideration point if you want to improve the mesh system’s compatibility with older wireless devices or smart home devices that you might have at home.

For example, I have a few LIFX light bulbs that operate on 2.4GHz band with 20MHz channel width. I was able to set that explicitly in the router and ensure the light bulbs stay connected. Previously on the D-Link Covr-2202, the LIFX light bulbs tend to lose connection and I would be left unable to control them from my phone.

Lastly, you are also future-proofing your home network as there will be more Wi-Fi 6 capable smartphones and laptops coming out in the later half of 2020 and the whole of 2021.