ASUS Zenbook Duo UX8406 review: The dual-display laptop perfected

Note: This review was first published on 23 February 2024.

Solving the notebook screen size conundrum

For notebooks, one of the most common trade-offs users have to make is between display size and portability. Larger displays often mean less portable notebooks. This is the rule.

ASUS, however, appears to have broken this once immutable rule with its newest notebook – the dual-display Zenbook Duo UX8406. In my time with it, I found that it has all the benefits that you'd think a dual-display notebook would have but with nearly none of the usual drawbacks. It appears ASUS has finally nailed the dual-display notebook. If you've always wanted a notebook with more screen real estate but don't want to sacrifice portability and usability, you'll want this notebook.

The TL;DR version:



A truly portable dual-display notebook with little to no compromises. Price aside, there’s simply no better notebook for anyone who needs lots of display real estate on the go. 

Anyone who has been following ASUS’ dual-display notebooks closely will know that the new Zenbook Duo UX8406 is a completely different animal. ASUS has completely ditched the design of its older dual-display notebooks – which have compromised secondary displays and cramped keyboards and touchpads – and gone for an all-new design that consists of two 14-inch OLED displays connected by a 180º degree hinge and a very thin detachable full-size wireless keyboard that can be stowed between the two displays for easy portability.

What’s incredible is that despite having two displays and a full-size keyboard, the Zenbook Duo UX8406 remains truly portable. Sure, at 19mm it’s a little chunky, but it only weighs 1.35kg – that’s about the same as a 13-inch MacBook Air and about 400g lighter than its predecessor. But numbers only tell half the story. If you didn’t know better and were handed the UX8406, you’d think it was just a regular notebook. It truly is no heftier than a regular 14-inch ultraportable.

The twin displays are impressive to look at and have outstanding specs. Both measure 14 inches, and when combined, they form a display size almost 20 inches across that can be used either in landscape or portrait modes. Both are OLED displays with a resolution of 2,880 x 1,800 pixels and a high refresh rate of 120Hz. They are also Pantone-validated and support 100% of the DCI-P3 colour space. 

As you can see, you can use the two displays in a few ways. My favourite is Dual Screen Mode, which makes use of the integrated kickstand to elevate the notebook so that you can put its two displays one top of the other in landscape orientation. My only gripe with this mode is that I wish you could attach the detachable keyboard to the bottom of the notebook and elevate it so that you can type at an angle – like how Microsoft’s Type Cover keyboards work with Surface Pros. 

Desktop Mode is another favourite of mine too and is especially handy when I’m writing (like I’m doing now) and need to refer to materials like white papers and spec sheets. In this mode, you place the notebook on its side so that the two screens are in a portrait orientation. One thing to note about this mode is that because of the design of the hinge and the need to accommodate the keyboard when the notebook is closed, the two screens aren’t level with each other and there’s a significant gap between the two. 

Hardware is just one part of the equation. The Zenbook Duo has software optimisations to let users take full advantage of the dual displays. For example, when you select a window, a shortcut appears to help you position them quickly across the two displays. Coupled with Windows 11's built-in windows management shortcuts, you can very quickly organise multiple windows and maximise the twin displays. For the most part, these shortcuts appear quickly and work fluidly, but there are times when there’s the odd lag.

Another key reason why this new dual-display notebook is such a joy to use is because of the detachable wireless keyboard. The keyboard attaches magnetically to the second display, and when attached, charges automatically via tiny pogo pins (check out the TikTok video walkthrough embedded above to see it in action). When it’s attached, you can hardly tell that it’s detachable and that there’s a second display underneath it. This aspect is what makes the ASUS incarnation of the dual-screen laptop more usable than other attempts from competitors.

Crucially, unlike its predecessors, which have severely compromised keyboard and trackpad setups, this new Zenbook Duo’s keyboard and trackpad feel just like a regular notebook’s. And despite being so thin, the keys have a decent amount of travel and feel tactile. The trackpad is excellent too. It’s large, smooth, responsive, and precise. My only complaint – as I alluded to above – is that I wish there were some way I could elevate the keyboard when it's detached. As it is, it’s very flat, and if you use it detached, it can be a little awkward to type on for extended periods. You can use the virtual on-screen keyboard too, but I won’t recommend it. It’s curiously slow and unresponsive, and I won’t use it for anything more than to do a quick search.

In terms of connectivity, you are not missing out on too much. Like most high-end ultraportable notebooks these days, this Zenbook Duo has two USB-C Thunderbolt 4 ports. I think it could use an extra USB-C port since you’ll need one of them for charging. It also has a single USB-A port (USB 3.2 Gen 1) and a full-size HDMI 2.1 port. Sadly, it’s missing support for the newest Wi-Fi 7 standard, but there’s still support for Wi-Fi 6E.

Welcome Meteor Lake

Note: Benchmarking results and charts are on the next page.

One of the key reasons why ASUS was able to design the Zenbook Duo UX8406 in such a way is because of the new Intel Meteor Lake processor it was using. Intel claims Meteor Lake is its most power-efficient processor yet and it's built on and using lots of new ideas and approaches. We’ve covered Meteor Lake in depth previously, and I urge you to read the following articles to find out more.

• Meteor Lake: Intel’s biggest architecture shift in 40 years to deliver significant gains
• Intel launches new Meteor Lake 'Core Ultra' processor lineup, bringing AI and Arc to ultrathin laptops
• We visited the factory that assembles Intel's next-gen Meteor Lake CPUs

The Zenbook Duo UX8406 we are testing is powered by the Core Ultra 9 185H processor with Intel Arc graphics, and has 32GB of memory and a 1TB M.2 PCIe 4.0 SSD. As you can see from the table below, this is the absolute highest specs you can get. 

What’s interesting about the configurations is that there isn’t one with the Core Ultra 7 processor and 16GB memory. When quizzed, ASUS said stocks of the Zenbook Duo were limited, but they hope to offer that configuration in the future.

This is our first time benchmarking a Meteor Lake notebook, and the results are largely positive. We saw significant gains in both CPU and GPU performance, especially in synthetic benchmarks like Geekbench and Cinebench. That said, the Zenbook Duo UX8406 did exhibit significant performance throttling – particularly in games and longer intensive workloads like video transcoding. But this is largely to be expected given its design and form factor. In real-world use, for productivity tasks, browsing the web, and watching videos, I have no complaints. This notebook felt smooth, responsive, and fluid in a way that older Intel notebooks don’t always do. Check out the following page for our compilation of results.

Battery life was pretty good, too. If you only use one of its displays, it’ll easily get through an entire day of work. Using both displays all the time on battery power might be a bit of a stretch unless you turn the brightness down significantly or have a short workday. With both displays at full brightness, it lasted just over four hours before calling it a day.

The best dual-display notebook yet

It’s probably a stretch to say that ASUS has perfected the dual-display notebook, given that some aspects of it could be improved, but they have certainly come closer to perfection than anyone else.

Comparisons will inevitably be made with Lenovo’s Yoga Book 9i, but I think the Zenbook Duo is the more considered product, mainly because of its lack of trade-offs. Unlike the Yoga Book 9i, its keyboard can be stowed away and easily carried, and it has an integrated kickstand. I also prefer the Zenbook Duo for its more conventional keyboard and trackpad. But I can understand why someone might want the Lenovo instead – it is the sleeker and slightly more compact of the two.

The crux is that ASUS hasn’t compromised much on portability and functionality – a problem that plagued this notebook’s predecessors and other takes on this genre. It’s roughly the same size and weight as a regular notebook, and it works just like one too, that is until the point you decide to remove the keyboard and deploy both displays. And that's why it's such a pleasure to use: it feels and works just like a regular notebook until you decide to deploy its twin displays. The flexibility and ways in which you can use both displays are good too. Furthermore, thanks to Intel’s newest processors, both battery life and performance are very decent.

But as I said, there’s room for improvement. More probably could be done to reduce the space and gap when used in Desktop Mode, and the keyboard could really use some sort of elevation when it’s detached from the notebook. And while we are it, it’s a good idea to have one more USB-C port. Two is a little stingy considering you’ll need to set one aside for power/charging. However, these are just minor misgivings and not dealbreakers. 

The biggest stumbling block is its price. With prices starting at S$2,999, it’s an expensive notebook; but the price is mostly justified considering it has two high-quality OLED displays and the amount of thought and engineering that went into it. Let's also not forget that its predecessor was S$700 more expensive; in comparison, the latest attempt from ASUS offers loads of advantages. Even so, there’s also no getting around the fact that there’s no shortage of decent regular ultraportable notebooks at half that price.

Ultimately, you’ll have to decide if the extra display and screen real estate is worth the price. But if you do decide to prioritize wanting those dual displays, rest assured that this is arguably the best dual-display notebook ever made yet. For its excellence, we've awarded the new ZenBook Duo UX8406 our coveted Innovation Award.

Note: You can find the Zenbook Duo UX8406 on the ASUS Online Store.

Benchmarking results

Here are the results of the ASUS Zenbook Duo UX8406. To recap, the review unit has Intel’s Core Ultra 9 185H processor, 32GB of memory, a 1TB M.2 PCIe 4.0 SSD, and Intel Arc graphics. With these specs, the Zenbook Duo UX8406 is S$3,399. 

As you can see, Intel’s new Meteor Lake chip delivers significant gains in performance across the board – particularly in multi-core workloads. This is the same for graphics too. Looking at the substantial frame rate gains in games, it’s clear that Intel’s Arc graphics is a more capable integrated graphics solution.

What these charts don't show is that we noticed pretty significant performance throttling. In games, for example, we saw frame rates dip as much as 35% after about half an hour of play.

Against Apple M-series

We didn’t have other Windows notebooks on hand to run the newer Geekbench 6 and Cinebench 2024 benchmarks, so here’s how it performed against some recent Macs. While it did reasonably well on Geekbench and Cinebench, it trailed badly when we timed it transcoding a 1GB Full-HD video file. In this test, it was even slower than an M2 MacBook Air.

Battery life

Battery life is quite remarkable and that’s due to the combination of a power efficient processor and a large battery. Even with two displays turned on and at full brightness, the Zenbook Duo managed to last over 6 hours. If you only use one of its displays, that runtime goes up to 8 hours, which easily makes it one of the longest-lasting notebooks we’ve tested. And if you look at our Portability Index, which takes into account a device’s dimensions and weight, it’s clear that the Zenbook Duo is just as portable as most 13 and 14-inch ultraportable notebooks.

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