Hardware Laptops Reviews

Asus ZenBook S UX391UA review: has the Dell XPS 13 finally met its match?

ASUS ZenBook S UX391UA review

Within a decade, Asus has gone from novice to one of the world’s premier laptop makers. The ZenBook S is a superb illustration of how far Asus has come. It’s a 13in ultraportable that trades on its looks while offering sufficient power for most people – including me. Read our Asus ZenBook S UX391UA review to find out if can topple the reigning champion, Dell’s brilliant XPS 13 .

Asus ZenBook S UX391UA review: design

Asus ZenBook S UX391UA review
Angle of attack: this is one way the ZenBook S lifts itself apart from rivals

First, I must tackle Asus’ decision to lift the keyboard like this. Its benefit? You have a slightly more natural typing angle, although I’ll come to that later. And it does catch the eye: no one has looked at this laptop without remarking on that design.

Even without it, this is a striking machine. Asus sent me a burgundy version, which is very sensible as that happens to be my favourite colour. As a keyboard surround, this looks absolutely lovely; it has a matte finish that reminds me of the Dell Inspiron 14, which stole my heart at the huge international tech trade show IFA.

I’m less convinced by the outside of lid. Asus applies its trademark swirl effect here, which is a divisive design choice. I find it inoffensive, but I do wish that Asus had opted for a matte finish to the lid rather than glossy. It’s all a bit, well, Trump.

That’s a shame, because its other design touches are much lighter and much more effective. I’m a fan of the gold backlight on the keyboard, for instance. This could have been awful, but it actually looks classy. Honestly, trust me.

Asus ZenBook S UX391UA review: all USB-C, no USB-A

Asus has again been bold with its choice of ports, abandoning traditional Type-A USB for the slimmer USB-C connector. In reality, it had little choice. There’s so little height on the chassis – my callipers measured it at 9.1mm – that it couldn’t fit anything else in.

Asus ZenBook S UX391UA review

Wisely, two of those ports are Thunderbolt 3 while one is USB 3.1 (USB-C denotes the physical ports; they can then support different standards, as we explain here). Thunderbolt 3 is a brilliant choice because it’s so fast and so flexible – you can even daisy chain 4K monitors through it, should you feel so extravagant.

For now, admittedly, it has downsides. Most of the devices people own are old-style USB, which means you’ll need to use the bundled USB-C to USB-A adapter to connect them.

Likewise it means, unless you’ve already bought a USB-C or Thunderbolt-equipped monitor, you must occupy one of those ports with the USB-C to HDMI cable that Asus also supplies if you want to hook up a monitor. A neater option is to add a third-party port replicator such as the Kingston Nucleum, but that, of course, adds to the cost.

Asus ZenBook S UX391UA review: display and keyboard

Asus ZenBook S UX391UA review

My review sample included a 1,980 x 1,020 non-touch screen, but you can opt for a higher-spec version with a 4K touchscreen. I think that’s unnecessary.

While this 13.3in screen didn’t excel in our technical tests, it’s absolutely fine. Want colour accuracy? The Dell XPS 13 has it licked. But if you just want to enjoy films and use it for everyday tasks then you’ll be happy. 

I would have liked it to hit a higher brightness than the 293 candela it managed in my tests, but if you’re going to use it indoors most of the time then I don’t see this as a problem.

Overall, I’m a fan of the keyboard, too. It has a pleasing, solid action, doesn’t make much noise, and the only minor irritation is the single-height Enter key. Even the cursor keys are well separated.

I question, though, how much the angle helps when typing. I quickly got used to it, but the slope didn’t feel any more or less comfortable than typing on the Dell XPS 13. And it comes with one obvious drawback: type with the ZenBook S on your lap and the edge of the screen digs into your legs.

The precision touchpad proved well-behaved, though, and even though the left- and right-click buttons are integrated rather than delineated, I had zero issues during use. I even like the fingerprint reader sitting snugly in the top right, although it could do with being a fraction larger.

Asus ZenBook S UX391UA review: power

The ZenBook S isn’t a fast laptop, but it is fast enough. My review sample included a nippy Core i7-8550U processor, but it was hampered by 8GB of RAM and a 256GB SATA SSD. If you choose a version with 16GB of RAM and a PCIe SSD, you can expect a boost from the speeds I measured.

These were fine, though. It managed 4,462 in the single-core Geekbench 4 test, rising to 10,940 for multicore. Note that the Dell XPS 13 I tested earlier this year – which admittedly had twice the RAM – was roughly 50% faster in the multicore test, despite having the same processor inside.

There isn’t room for a dedicated graphics chip, with Asus settling for the UHD Graphics 620 built into Intel’s processor. And that’s absolutely fine for light 3D gaming such as Minecraft. Fortnite, on the other hand, is too big a challenge. 

Asus ZenBook S UX391UA review: test results

SSD tests
AS SSD sequential read speed453.4MB/sec
AS SSD sequential write speed 210.3MB/sec
AS SSD 4KB files read speed24.7MB/sec
AS SSD 4KB files write speed 46MB/sec
Geekbench tests
Geekbench single-core4,462
Geekbench multicore 10,940
GFXBench graphics tests
Car Chase offscreen 1080p  17.8fps
Manhattan 3.1.1 offscreen 1440p14.2fps
Manhattan 3.1.1 offscreen 1080p25.5fps
Screen tests
sRGB colour gamut coverage82.9%
DCI-P3 colour gamut coverage64.4%
Average/Max Delta E4.7/11.6
Measured contrast ratio1,138:1
Battery life9hrs 2mins

Asus ZenBook S UX391UA review: verdict

I like this laptop. I don’t think I’d ever tire of looking at the gorgeous burgundy finish and golden key backlights; it’s a classy combination. It also offers all the power I need from a serious, workhorse laptop. I can live with the lower specification too.

I love other elements too. The two Thunderbolt 3 ports, the rapid charging, the excellent battery life, the fact I can sling this tiny wee thing into my bag and not worry about adding a power supply. (And, as time goes on, USB-C power supplies are likely to become ubiquitous in offices you visit.)

I’m less convinced by its wedge design and – sorry Asus – but I think the shiny lid is a design mistake. It’s too ostentatious.

So to the big question: has the Dell XPS 13 finally met its match? For sheer portability, I’d give the XPS the edge. The Asus is lighter (1.1kg versus 1.2kg) but a fraction more portly at 13.1mm to the Dell’s 11.6mm. The XPS also kept going for another hour in our battery despites.

However, the ZenBook’s styling also makes the Dell look old-school and boring. But there is a caveat: there are only two models available right now: the UX391UA-EA028T and the UX391UA-EA055T. Both are “Deep-Dive Blue” rather than our burgundy review unit.

The EA028T includes a Core i5-8250U processor, although I wouldn’t expect it to score much slower than the Core i7 version I tested, but includes a 4K screen. It currently costs £1,188 from Amazon.

Spend another £112 and you can buy the £1,300 EA055T, but all you get is the faster processor. Everything else stays the same. Is it worth it? I think most people wouldn’t notice the difference in practice, so I’d lean towards the cheaper version.

Dell XPS 13 vs Asus ZenBook S
The Dell XPS 13 is available in either aluminium grey or white, but neither are as striking as the Asus ZenBook S’s burgundy finish

It’s useful as a price barometer, though, because the equivalent spec Dell costs £1,499. Now that does include a better warranty – a year of on-site support, rather than the return-to-base cover of the Asus – but there’s no doubt which is better value.

If you only have £1,200 to spend, you must drop down to a 1,920 x 1,080 screen on the Dell XPS 13 – but you still get the superior warranty.

So it’s not a straightforward choice between the two. Asus definitely offers better value, but if you don’t want the 4K screen then that doesn’t matter. For now, I’d play the holding game: if Asus ends up selling the burgundy version with a 1,920 x 1,080 screen for less than £1,000, I’d be very tempted to buy.

Read this next: Should you save £350 and buy the HP Envy 13 instead?

Asus ZenBook S UX391UA
  • Power
  • Design and features
  • Value for money


A slender, light and highly alluring 13.3in ultraportable for a reasonable price

About the author

Tim Danton

Tim Danton is editor-in-chief of PC Pro magazine and has written about technology since 1999. He enjoys playing with gadgets, playing with words and playing tennis. Email tim@bigtechquestion.com

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