Xiaomi Mi Mix 18K Review: A Slippery Slice of the Future

BY Steve Litchfield

Published 29 Dec 2016

Smartphones have been getting closer to this Star Trek-like form factor for years. Just as the original Samsung Galaxy Nexus appalled us all with a giant 4.7” screen in 2011, a vision of the future from Google, the Xiaomi Mi Mix here with a screen that almost touches the edges on three sides, with a 6.4” display in a form factor smaller than any previous sub-6” phablets, is a clear indication of where things are going. And we know where they’ll end up – we saw it on TV, on Star Trek Next Generation 20 years ago…

There’s only one problem. Xiaomi conceived this to look beautiful, to feel beautiful, and with zero thought as to real world usability. And I’m not talking about the missing earpiece, relocated front camera or even the minimal bezels – the Mi Mix, used as-is, is a usability nightmare because it’s polished ceramic, top to toe, front to back, and edge to edge. It slides off every apparent flat surface, every resting place, it never feels secure in the hand. I found myself having to artificially wedge it on desks and kitchen surfaces twenty times a day, otherwise it would be on the floor in no time!

Xiaomi Mi Mix review

Is the Mi Mix durable enough to fend for itself? Not really. Ceramic is a heat-hardened compound that’s a cousin of glass, but (obviously) not transparent. It’s extremely hard and scratch resistant but also very brittle, meaning that when the Mi Mix is dropped onto a hard surface then the outer casing will shatter into a hundred pieces and so will the display, since shocks are transmitted directly through the phone and its display.

This isn’t the only phone to be made from this material, of course, the OnePlus X had similar ideas. But the polished finish all over is its downfall here. A case is not only recommended, it’s absolutely de rigeur. And thankfully a basic case is supplied with the phone, in the box.

But it all makes a complete mockery of putting so much attention to arty design into the materials since no one will ever see them – even the owner of the phone. It beggars belief.

Xiaomi Mi Mix review

But let’s put the materials to one side and assume that you’ll be using a case 24/7 – is the Mi Mix’s Unique Selling Point, its 6.4” display in the body of a 5.7”-screened phone, remarkable enough to warrant a recommendation to buy from me? Well, almost… it very much depends where you live in the world!

The core specifications are mightily impressive: a Snapdragon 821 chipset with 6GB of RAM (of which over 4GB is available after booting) means that everything flies, with a whopping 256GB internal storage meaning that you’ll never run short of capacity, however many 4K videos you shoot.

That Qualcomm chipset also means that the Mi Mix can come with Quick Charge 3.0 fast charging over USB Type C, though you’d have to source your own mains accessory here – you only get a cable in the box. Charging is indeed fast from my own kit, though even at up to 12V the large 4400mAh battery here will take a couple of hours to fill. But equally that kind of capacity means that you’ll never run short of power before the end of the day, however large the display. Helped by the latter being ‘only’ 1080p.

Xiaomi Mi Mix review

1080p? Some mistake, surely, on a 6.4” screen? Actually no – obviously at a premium price point for 2017 you’d expect Quad HD, but to my eyes an IPS LCD panel looks crisp even 1080p – this is a full RGB stripe, unlike on all the AMOLED-screened phones out there. And yes, having fewer pixels to push around reduces the power drain when the Mi Mix Pro is in use.

With no space above the giant screen, the earpiece and proximity sensor have been moved underneath the display glass – and they work just fine. Admittedly the piezoelectric speaker, though aimed outwards at your ear, also transmits sound through the phone generally, so others around you will hear your caller’s voice substantially more than on a traditional handset, and this may be an issue for potential buyers on privacy grounds.

Also moved is the front camera, here now positioned down at the bottom of the phone’s frontispiece, though in use it’s restored to the top, with a ‘first time use’ on-screen animation prompting you to rotate the phone. It’s a little clumsy and you can still make video calls with the camera at the bottom, but don’t expect your eye-line to make good contact with the other party!

Mi Mix review detail

Down at the very bottom is the traditional iPhone 6 layout of two speaker grilles, the left of which is a cosmetic dummy and the right of which is a quite decent mono loudspeaker. It’s right up there with the iPhone 6s Plus’s and the best of the handsets which don’t have full front mounted stereo speakers, plus it’s backed by stunningly good audio output from the 3.5mm headphone jack on the top. Very little to complain about here.

Around the back is another familiar layout, with camera glass, dual LED and a fingerprint sensor, with the main two openings inlaid with 18 karat gold, this being the top of the line Mi Mix (there’s also a version without the gold, with less RAM and storage, for $300 less).

Mi Mix review detail

The camera’s interesting in that it’s not quite as premium as the rest of the handset. This is absolutely understandable given the physics involved – Xiaomi wanted an 8mm thick ceramic obelisk, with nothing protruding, let alone a camera bump, so the camera glass has actually got to be recessed into the back, for protection purposes. Giving around 5mm of internal thickness, at most, for a 16MP camera. Ouch.

Something, as you can imagine, has to give and we have the classic 1/3″ sensor with 1 micron pixels here, i.e. pretty small, with no OIS, and wide angle optics. In good light conditions, results are more than acceptable, but in artificial and low light it all goes somewhat to pot. This may not be an issue for potential buyers of such a halo form factor, mind you – just don’t buy this for a flagship camera to match the price tag.

Here are a number of sample photos, together with 1:1 crops to show detail and quality:

Full sample photo, downscaled for the web

1:1 detail from the photo above

1:1 detail from the photo above. There’s noise here which shouldn’t be there – showing the limitations of a 16MP sensor in such a small form factor.

Full sample photo, downscaled for the web

1:1 detail from the photo above

1:1 detail from the photo above, perhaps a little over-sharpened, but scrubbing up quite nicely, the Mi Mix did well here!

Full sample photo, downscaled for the web

1:1 detail from the photo above

1:1 detail from the photo above, details starting to get a tiny bit murky, but still a great photo overall.

Full sample photo, downscaled for the web

1:1 detail from the photo above

1:1 detail from the photo above. Indoors, you can see evidence of artefacts and blurriness – expected from a small sensor like this.

Full sample photo, downscaled for the web

1:1 detail from the photo above

1:1 detail from the photo above. And, with no OIS, night shots are often a disaster. Even when exposure is good – as here – handheld shots manage to blur out finer detail.

Video recording is at 4K, and even at 1080p there’s no digital stabilisation, which seems like an omission, given the immense processing power here. Maybe something for Xiaomi to add in an update.

Talking of which, this is the new MIUI Global 8.0 on top of Android 6.0.1 – though I understand a version on Nougat is imminent. Xiaomi do issue updates to their various phones, though as an international customer rather than a Chinese native, you’re somewhat at the mercy of the status of each firmware, depending on where you bought from. This review device was originally bought from geekbuying.com and arrived with English and other world languages and with the Google Play Store installed. Which means that I was then able to seek out and install every other Google application which you’d normally find on an Android handset, as shown below. Phew!


As to quite how official this build is in terms of eligibility for Xiaomi OS updates and patches… is hard to say at this stage. I’m optimistic, but you don’t get the warm fuzzy feeling here that you might get from the likes of Google itself, HTC or Samsung, that you’re ultimately in safe hands.


Perhaps partly demonstrating the pitfalls of buying phones with err…. modified OS builds, this Mi Mix had a set-up bug which saw it not letting me set my location as in the UK or USA, the two locales which often get separated off at the head of an English language list of countries, since they’re the most common. Presumably the team in charge of compiling this International build of MIUI had intended to do this and simply forgot them – so I’ve had the phone pretending I was (physically) in Spain!


Not that it matters that much in terms of setting up the cellular radios, since the European LTE band 20 is nowhere to be seen here – you get bands 1 through 8 and 38 through 41, and that’s your lot. With a few exceptions, many European users will have to make do with 3G bands for calls and data. In the fulness of time perhaps Xiaomi will create a genuine world edition of this Mi Mix hardware? You do get Wi-fi to ‘ac’ and 5GHz support, plus NFC, thankfully, so it’s not all bad news here, and there are two nano SIM slots, giving some flexibility when travelling around the world.

MIUI comes with an entire raft of Xiaomi built-in applications, of course. Some useful, though most becoming redundant once I’d installed the Google originals – so Contacts, Calendar, Photos, Maps, and so on. And the Xiaomi applications can’t be uninstalled, so you’d have to hide them in a suitable homescreen folder in the usual way – there’s no app drawer here, so everything lives on the homescreen panorama somewhere. This isn’t a huge issue though it does make for quite a bit of set up time for the experienced user who knows what they want to see and who wants the real Google first party applications.

Otherwise this is a fairly standard Android set-up, with virtual controls – and yes, you can swap which side the back control is on, in Settings. Thankfully. In fact, you can also swipe away the controls altogether if you want to, within a specific application, for absolute maximum screen real estate, just as Windows 10 Mobile. Most of the time this isn’t needed, not least because the screen is an unusual 17:9 aspect ratio, meaning that you can fit a 1080p game or video image plus controls, with no content missing. Software permitting, that is – this 2080 by 1080 pixel screen doesn’t have universal app and game support!

At the bottom left of the controls is a small dot – tapping this brings up the so-called ‘Quick Ball’ onto the UI. This can be dragged around as needed and offers customisable shortcuts. By default, home, menu, lock, screenshot and back, but I quickly got reassigning, with Clock, Torch, Android Pay, and so on.

Quick Ball UI

Quick Ball is MIUI’s biggest indulgence and it’s not terrible. I could see myself using it sometimes, a five shortcut splay from one tap – though that semi-transparent hovering ball did annoy from time to time!

Nice touches in MIUI 8 include being able to swipe down the notifications and quick settings shade with a gesture from anywhere, i.e. you don’t have to start right at the top of the (here) huge 6.4” display – this helps enormously.

Notifications and second space

Notifications (swipe-able down from anywhere in the UI, from any screen starting point); and (right) ‘Second space’, a complete second virtual Android phone alongside your main instance!

‘Second space’ is another Xiaomi addition – essentially a second instance of all your apps and data within the same storage – perhaps one virtual phone for work and another for your personal life, but far more likely is that you’d keep the second instance for family to play games on the big screen without messing up your own data and set-up. Just make sure your ten year old kid doesn’t take your phone case off and only used the Mi Mix in carpeted areas!!

As usual with Chinese Android OS versions, there’s a supplied Security suite, here with a disk cleaner and anti-virus scanner. Oh, heck, why not, if you’re using modified Chinese ROMs in the first place, better safe than sorry, right?

Security suite

Finally, Xiaomi have put in a really nice ‘slide under’ system for moving applications between homescreens – just tap and hold an icon with one finger and then slide the homescreens underneath like a conveyor belt, releasing when you spot where you want to drop the icon. This should really make it back to the Google mothership in my opinion.

Designed by Xiaomi

The Xiaomi Mi Mix is gorgeous to look at and, once configured, superb to use, with high spec components throughout, camera permitting (for space reasons). As Unique Selling Points go, having almost zero bezels on three sides comes pretty high on the list and I wouldn’t be at all surprised to see more and more smartphones come with similar designs in 2017. Imagine a phone with a 5.5” display in the body of what normally houses a 5” screen. Oh wait, such a Mi Mix ‘nano’ is already rumoured from Xiaomi – but they won’t be alone here. All I’m asking, aside from a properly thought out ‘world edition’ in terms of updates, bands and regions, is that the polished ceramic finish be dialled down somehow – smartphones don’t need to also be works of art!