Asus RT-AX88U vs. RT-AC88U: The Same Router of Two Wi-Fi Standards

RT AX88U vs RT AC88U 5
The Asus RT-AX88U (left) looks almost identical to the RT-AC88U.

RT-AX88U vs. RT-AC88U is an interesting comparison since they are of two different Wi-Fi standards. Right off the bat, it seems the former, the Wi-Fi 6 version, is a clear replacement of the Wi-Fi 5 counterpart. But is that really the case? Find it all out in this post.

RT-AX88U vs. RT-AC88U: Similarities

Just take a good look at them. They are almost identical. Indeed, these two routers share the same design, dimensions, weight, number of network ports (eight LANs and one WAN), and antennas. And there’s more.

On the inside, they both have the same set of features, including gaming, online protection, QoS, and so on. The two can also work together to create an AiMesh Wi-Fi system.

Most importantly, you can put Merlin firmware on both and turn them into much better Wi-Fi machines than what you get out of the box. In fact, the support for Merlin is among the main reason I’d consider these two.

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RT-AX88U vs. RT-AC88U: Hardware specifications

RT-AX88U vs. RT-AC88U: Differences

The biggest difference between the two is the fact the RT-AX88U is a more powerful router. For one, it uses Wi-Fi 6. It also has a faster quad-core CPU and doubles the amount of RAM and flash memory.

The RT-AX88U also has two USB 3.0 ports (instead of one 2.0 port) and, in my testing, delivered much faster network storage performance when hosting a portable SSD.

In many ways, the RT-AX88U supersedes RT-AC88U as it’s intended to be. However, the lack of a multi-gig port means, in reality, you likely won’t see much difference between the two in terms of network Wi-Fi performance.

RT-AX88U vs. RT-AC88U: Performance

It’s expected that the RT-AX88U would outdo the RT-AC88U and, for the most part, it did in my testing. However, having no multi-gig port, it wasn’t that much faster when working with Wi-Fi 5 clients.

By the way, I originally tested the RT-AC88U using only Wi-Fi 5 clients. There was no Wi-Fi 6 one during the time I reviewed it and it doesn’t have Wi-Fi 6 anyway.

But like all Wi-Fi 5 routers, it works with Wi-Fi 6 clients, or the other way round — Wi-Fi 6 clients work with Wi-Fi 5 broadcasters.

In any case, for this post, I did some additional tests using 2×2 Wi-Fi 6 clients, which connected to the router at 867 Mbps of negotiated speed. That’s the ceiling speeds of 2×2 Wi-Fi 5.

RT AX88U vs RT AC88U

By the way, both routers can host network storage via a portable drive. But of the two, only the RT-AX88U can really work as a mini NAS server. It had much faster NAS speeds, as shown here, thanks to the higher hardware specs.

RT-AX88U vs. RT-AC88U: Ratings

ASUS RT-AX88U AX6000 Dual-Band Wi-Fi 6 Router






Design and Setup





  • Fast Wi-Fi performance
  • Tons of useful features
  • Eight network ports with Dual-WAN and Link Aggregation
  • Universal setting backup and restoration
  • Fast network attached storage speed when coupled with an external drive.
  • Merlin firmware support


  • No multi-gig network port
  • Buggy firmware (at review)

Asus RT-AC88U Wi-Fi Router






Design and Setup





  • Fast Wi-Fi performance with excellent coverage
  • Tons of useful features including the ability to guard the network against online threats
  • Eight LAN ports with Dual-WAN and Link Aggregation
  • Excellent support for Asus's AiMesh
  • Merlin firmware support


  • Awkwardly placed USB 3.0 ports
  • Slow network storage speed when coupled with an external hard drive

Which to get

In my anyways, the RT-AX88U is better than the Wi-Fi 5 counterpart. But it’s also much more expensive while sharing the same feature set.

So if you’re still having a lot of Wi-Fi 5 and legacy clients, the RT-AC88 is a better choice. Put the Merlin firmware on it and you’ll be amazed by what it has to offer.

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And then, when you’re ready to upgrade to Wi-Fi 6, keep it, it’ll still work great as an AiMesh node, especially if you have wired your home with network cables.

The RT-AX88U is also a great router. But unfortunately, the lack of multi-gig network ports means you won’t almost see its full potential. For that reason, you should consider the more affordable yet multi-gig-ready RT-AX86U instead.

Looking for more Wi-Fi solution matchups? Check them all out here.

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2 thoughts on “Asus RT-AX88U vs. RT-AC88U: The Same Router of Two Wi-Fi Standards”

  1. Although there are only currently 2×2 WiFi 6 clients, which makes testing their throughput limited, there’s another way to test the peak WiFi 6 capability of WiFi 6 routers.

    What to do is to use two WiFi 6 routers, and one of them in router mode and the other one repeater/client/media-bridge mode. So one router transmits and the other one receives. Assuming both routers have a multi gig port, you can connect computers to the multi gig ports and test lan transfers. I did exactly this, one WiFi 6 router in the main room, and the other one about 50 feet away. Using 80 MHz channels, the routers connect to each other at 2.4 Gbps. And iperf3 shows a cool 1.6 to 1.7 gbps transfer speed which is pretty damn good. No need to run a wire, although performance would be better (on wireless clients of the repeater if it has dual 5 GHz radios… just use one for backhaul).

    I tried using 160 MHz channels to test but that was a disaster. One router detects radar on the upper 160 MHz channel (the other one doesn’t detect any radar) and then when I use the lower 160 MHz channel the situation is reversed. So I had to stick to 80 MHz. But 1.7 gbps on 80 MHz isn’t too bad at all.

    • You can do the same thing using multiple 2×2 clients at the same time and adding the numbers up, Joey. I do that for some of my reviews. The issue is the repeatability of the tests which allows you to apply to all routers so that a fair comparison is valid.


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