It's been a long time since a new phone announcement got us as excited as has the Mi Mix. This revolutionary new phone gives a taster of what to expect from the smartphone market over the coming years.

Mi Mix review: Core hardware and performance

Until the next batch of annual flagship smartphone upgrades arrive at MWC at the end of February 2017, the Mi Mix has a hardware specification to match any rival. There's the powerful Qualcomm Snapdragon 821 quad-core processor running at 2.35GHz, with integrated Adreno 530 graphics and 6GB of LPDDR4 RAM. This matches the specification of the OnePlus 3T, with very similar performance. 

In real-world use the Mi Mix is a speed demon in everything it does. Nothing seems to tax it, and it doesn't get even warm in use. You simply can't fault the Mi Mix on performance. No user will pick up the Xiaomi and think it's slow when navigating menus, launching apps or multitasking and, thanks to the full-HD screen, its gaming performance is also very good.

We use Geekbench 4 and AnTuTu to measure overall processing performance, and in the former test the Mi Mix gave the best result we've seen yet with its 4301-point score a touch higher than the OnePlus 3T's 4257. It also gave the highest result we've ever seen in AnTuTu 3D, with 144,430 points (unfortunately we don't have results for the OnePlus 3T here).

GFXBench is used to test graphics, and the Mi Mix didn't let us down here. With scores of 60fps in T-Rex, 46fps in Manhattan, 32fps in Manhattan 3.1 and 20fps in Car Chase its gaming performance is incredible, and right up there with all the other 2016 flagships.

Our final benchmark is the JetStream JavaScript benchmark, and here the Mi Mix turned in scores in line with its rivals with an average of 53.787.

You can compare the Mi Mix's performance to other top phones of 2016 in the chart below. Also see: Fastest phones 2017

A highlight of the Mi Mix is its 256GB of fast UFS 2.0 storage. There's no microSD support on this phone, but with such a huge amount as standard plus the flexibility of cloud-storage services such as Google Photos, Google Drive and even Xiaomi's own MiCloud, running out isn't going to be an issue.

Battery life is incredible, and way beyond that of the Mi Mix's closest rivals. Even with heavy usage we can get two days of life from this phone thanks to its 4,400mAh battery, and with lighter use you could potentially get longer. There's Quick Charge 3.0 support too, which when paired with a compatible charger can charge the battery four times faster than a standard charger. Combine the two, and the vast number of power banks we've collected over the years is here largely redundant. If we had to complain, there's no support for wireless charging and the battery is not removable.

Mi Mix review

Mi Mix review: Connectivity

The Mi Mix supports UK 4G bands 3 and 7, but not 20 (also known as 800MHz). According to GearBest its cellular connectivity is as follows: GSM: B2/B3/B5/B8, CDMA: 1X/EVDO BC0, WCDMA: B1/B2/B5/B8, TD-SCDMA: B34/39, FDD-LTE: B1/B2/B3/B4/B5/B7/B8, TD-LTE: B38/B39/B40/B41.

All the main UK mobile operators own bandwidth in the 800MHz frequency, but only O2 uses it exclusively for 4G. What this means is all users might find they are unable to connect to 4G in some places it was previously available to them, and 4G won't be available at anyone on the O2 network. This also applies to customers of virtual mobile operators that piggyback O2's network, such as GiffGaff and Sky Mobile.

Using a Vodafone account we haven't found connectivity to be an issue with the Mi Mix. It seems as though we are able to access 4G less often than we were with a previous phone that supported the 800MHz band, though it's impossible to tell for sure without running the two side by side. We have always been able to access 3G or a nearby Wi-Fi connection in any case, so calls, texts and mobile data usage haven't been a problem.

Mi Mix review

While you probably wouldn't want one of them to be an O2 SIM for obvious reasons, the Mi Mix is a dual-SIM dual-standby phone, which means you can add and operate two SIMs (both are Nano-SIMs). Only one can be used for mobile data, but you can choose which you want to use for calls and texts and accept them in return on either SIM. This is ideal for business users who want separate phone numbers for work and home, and also for those venturing abroad and wish to take advantage of a local SIM.

MIUI 8 supports dual apps, which means you can run two instances of the same app with both icons displayed on the home screen. For apps that require a phone number to sign in - for example WhatsApp - this can be very handy and would allow you to have separate accounts for each of your SIMs. Also see our dual-SIM phones buying advice and Best dual-SIM phones round-up

In other respects all connectivity bases are covered, with dual-band 802.11ac Wi-Fi, Bluetooth 4.2, NFC, USB-C, GPS and GLONASS. Although Google Maps isn't preinstalled on the phone it's very easy to quickly install from Google Play.

It's been a long time since a new phone announcement got us as excited as has the Mi Mix. This revolutionary new phone gives a taster of what to expect from the smartphone market over the coming years.

Mi Mix review: Cameras

The camera setup on the Mi Mix is a little different than it is on most phones, given that we've lost the top bezel of the phone. Instead the selfie camera is located at the bottom right corner of the phone, which is, to be honest, plain weird. 

When you launch the selfie camera the focus is completely wrong, capturing you from the chin (or chins - it's not a flattering angle) up and with you appearing to look into the sky. The only way around this is to turn around the phone, which places the camera at the top left of the phone. It's annoying, but we don't see a better solution - and clearly neither did Xiaomi.

The selfie camera itself is as good as any, rated at 5Mp and with many of the same features as the main camera app. You can access real-time previews that allow you to apply Lomo, Color pop, Rustic, Icy, Vivid, Analog, Matte, Mono and B&W filters, as well as a handful of fun effects including Sketch, Spread, Squeeze, Stretch, Fisheye, Mosaic, Mirror and Tunnel. There's a countdown timer, an audio mode that will pick up when you say "Cheese" (or whatever comes to mind) and countdown from three, and a GroupShot mode.

By default a Smart Beauty filter is set to Medium, and you can alternatively set it to Low, High or off. If you want more control the Pro mode offers a sliding scale for skin smoothing, face slimming and eye widening.

All these options are also available for the Mi Mix's primary camera, plus you get modes for Panorama, Manual, Straighten, Square, HHT and Tilt-Shift. Both HDR and the Flash can be on, off or set to auto, and are available from the top of the screen. Meanwhile, pressing and holding the shutter button triggers a burst mode - you can also use the volume buttons to take a photo - and in the settings you'll find options for adjusting contrast, saturation, sharpness and exposure.

This camera is unsurprisingly better specified, and as well as 16Mp stills (by default at 4:3) it can capture 4K video at 30fps. It supports EIS, phase-detection autofocus and is paired with a dual-tone flash but, to be frank, at a time when others are offering phones with fancy features such as dual-cameras on paper at least it's nothing special.

What really counts, though, is the quality of the photography. And the Mi Mix does a pretty decent job given adequate lighting. As you'll see from our standard test shots of the St Pancras International Renaissance Hotel below, in auto mode and with HDR engaged, photos are dripping with colour - these images were shot in the UK in January! Detail is very good, even capturing ground-level road names when shot from our seventh-floor roof terrace, but there is some blurring - particularly in HDR mode. Also see: Best camera phone 

Mi Mix review

Mi Mix review

Mi Mix review: Software

Many readers will be unfamiliar with the MIUI 8 operating system running on the Mi Mix. It's a custom version of Android Marshmallow, but one of the largest departures from it.

The most obvious difference between MIUI and vanilla Marshmallow is the lack of Google apps. With most Xiaomi phones we review, we would be talking about a complete lack of Google apps and Google services - if you wanted to even add a Google account you'd need to sideload the Google Installer APK and install the Services Framework and any other necessary services. Fortunately, the Mi Mix we received from GearBest is running the International ROM, so although we still had to add our own apps such as Maps and Drive and set up their permissions to allow them to run smoothly it did at least come with the Google Play Store and the ability to add a Google account out of the box.

Mi Mix review

In another nice surprise, the Mi Mix came with no bloatware preinstalled, and we saw no Chinese-language apps and notifications. Although we'd like to have the ability to uninstall some of the original apps that now duplicate functionality for our preferred Google apps, we can hardly say they are junk. The difference between MIUI and Android is you don't need a Google account as long as you have a Mi account - everything you need is here. Also see: Best custom Android UIs

Another big change from Marshmallow is the removal of the apps tray. As it is in iOS, everything installed on the phone is displayed on the home screen. We used to strongly dislike this approach and the resulting mess of apps cluttering the display, but then we found folders - the virtual equivalent of chucking everything in a cupboard and tidying it another day. We're still not entirely convinced, but it does make it easier to find things which may otherwise have lost their home screen shortcut following an update.

Mi Mix review

Finding things can be an issue with MIUI 8, simply because the Settings menu is so different to that of standard Android. Not everything is where you might expect to find it, so it's great that there's a search bar at the top of the Settings menu: type in what you're looking for and you never need know in which Settings option it is actually located.

One of the new features in MIUI 8 is the circular quick-access toggles for frequently used features (mobile data, Wi-Fi, Bluetooth and so on) when you pull down the notification bar at the top of the screen. You'll also find new features such as double-tap to wake, Second Space (which creates a separate space on your phone), individual App Lock and support for Mi Wallet, plus all the other handy features we've mentioned throughout this review.

Read next: Best new phones

Specs

Xiaomi Mi Mix: Specs

  • 6.4in full-HD (2040x1080, 362ppi, 17:9) edgeless IPS LCD with 91.3% screen to body ratio
  • MIUI 8 (based on Android 6 Marshmallow)
  • 2.35GHz Qualcomm Snapdragon 821 quad-core processor
  • Adreno 530 GPU
  • 6GB LPDDR4 RAM
  • 256GB UFS 2.0 storage
  • ceramic body designed by Philippe Starck with 18K gold fingerprint scanner and rear camera surround
  • ultrasonic distance sensor
  • cantilever piezoelectric ceramic acoustic technology
  • dual-SIM dual-standby (2x Nano-SIM)
  • dual-band 802.11a/b/g/n/ac Wi-Fi
  • Bluetooth 4.2
  • GPS, A-GPS, GLONASS
  • NFC
  • USB-C
  • 192kHz/24bit audio
  • 16Mp rear camera, f/2.0, EIS (gyro), phase detection autofocus, dual-LED (dual tone) flash
  • 5Mp front camera
  • video recording: 2160p at 30fps, 1080p at 30fps, 720p at 120fps
  • 4400mAh lithium-ion battery, non-removable, with QC3
  • 158.8x81.9x7.9mm
  • 211g
  • 4GB RAM/128GB storage model also available