Xiaomi Mi 4i:Review

Xiaomi is one of the more interesting OEMs out there. While some smartphone OEMs seem to be in autopilot mode, Xiaomi looks like it’s built for disruption. It combines great build quality and specs for prices that are often half that of the competition. We’ve mostly paid attention to the company’s flagship lineup—the Mi 4 and the Mi Note—but when even the high end stuff is only $480, what do the company’s lower-end offerings look like?

Today we’re looking at the recently launched Mi 4i, a Xiaomi phone that costs just $200. The price puts it in the same ballpark as the $180 Moto G, but compare the specs and you’ll see that Xiaomi blows away Motorola’s nearly year-old phone. The 2014 Moto G has a 5-inch 720p display, a 1.2GHz Snapdragon 400, 1GB of RAM, 8GB of storage, and an 8MP camera. The Mi 4i takes those specs and bumps just about everything up a tier. You get a 5-inch 1080p screen, a1.7GHz (64-bit) Snapdragon 615, 2GB of RAM, 16GB of storage, and a 13MP camera. Neither device has NFC, but the Mi 4i trades the microSD slot for a second SIM slot, and—oh yeah—the Mi 4i has LTE. The best part is the battery: the Moto G has a 2070 mAh battery, but the Mi 4i has a much larger 3120 mAh battery.

That’s a huge difference between the two devices. You might think it’s because the Moto G is from 2014, but the rumored 2015 Moto G specs are pretty similar. The difference, (besides the extra $20) is something we’ve seen over and over from Xiaomi: it has lower prices than anyone else.

The 3120 mAh battery certainly seems impressive, but it didn’t score as well as we were expecting in our battery tests. The battery life is comparable to the Moto G, but despite packing an extra 1050 mAh, the Mi 4i doesn’t blow it away. Still, it’s nice to see a battery this big in such a compact device. Almost all the smartphones we try out have great screens, fast processors, and speedy connectivity. In the battery department, we’re always looking for more.

Design and Materials

When it comes to building a phone, Xiaomi seems to have something figured out that the rest of the industry hasn’t. The Mi 4i is solid, compact 5-inch device that feels like it’s worth a lot more than $200. It’s plastic—perfectly acceptable at this price range—but there isn’t an ounce of give to the body. It’s not a unibody milled plastic construction or anything, but it feels about as good as the plastic version of the $650 LG G4 we recently reviewed.

The Mi 4i feels a lot like a sturdier Nexus 5. The two devices are about the same size—138.1 x 69.6 x 7.8 mm for the Mi 4i and 137.9 x 69.2 x 8.6 mm for the Nexus 5. They both have a flat, matte plastic back that curves up around the mostly flat sides of the device. The Mi 4i’s compactness is very impressive. It manages to be thinner than that Nexus 5 and way thinner than the 11 mm Moto G.

The only minor build quality items we’ll complain about are the buttons. To start, the volume and power buttons have a cheap-looking glossy silver paint. They don’t jiggle much and the action is just fine, but it’s easy to scratch the paint.

For some reason, the Mi 4i also still has a hardware menu button. There aren’t really any menus in the software anymore, and pressing the “menu” button here actually opens recent apps. Yet Xiaomi never changed the icon from a menu symbol. Years of training—including with Xiaomi’s past products—have taught me that this symbol means “menu,” so when you press it and it isn’t menu, it’s a little weird. It creates an unnecessary cognitive load; you have to stop for half a second and think about what the button willreally do. Even if you ignore the history of that symbol, the actual recent apps interface is either a horizontal list of app icons or a horizontal list of thumbnails, making three vertically stacked lines completely unrepresentative of what will happen on the screen.

Like every other Xiaomi device we’ve used, this has one of those odd micro-USB “A/B” ports. What we consider to be a normal, trapezoidal micro-USB plug is actually called “micro-USB B.” There also exists a rectangular micro-USB plug and port combo called “micro-USB A,” which you can see a picture of on the right.

The Mi 4i can accept either cable, which means the port on the bottom of the phone is just a big rectangle. If you have a micro-USB B cable, like nearly everyone on the planet, the rectangular port makes it even harder than usual to figure out which way the micro-USB plug goes. The only real indication is to look inside the port to find the little black tongue and line it up with the hole in the USB cable. You could definitely jam a “normal” micro-USB cable in the port incorrectly without much effort. This would probably break the port and ruin the phone, but we aren’t going to try. (When will those USB type-C ports be ready again?)

The back isn’t technically removable, but the Mi 4i is pretty easy to disassemble with the right tools. When we went to pick one up, Xiaomi’s VP of International Hugo Barra stripped a Mi 4i down to the motherboard with nothing other than a plastic pry tool and a Phillips screwdriver.

Hey, this looks familiar…

Xiaomi’s Android skin is called “MIUI” (pronounced “Me you eye”), and it’s up to version 6. Xiaomi takes its Android skinning very seriously; in fact, MIUI was the company’s first product when it started out. Like CyanogenMod, the skin is available as a ROM for download and installation on hundreds of Android devices, even non-Xiaomi ones. The company has an insane weekly development cycle for MIUI betas—code Monday through Wednesday, ship Friday, get user feedback Saturday and Sunday, and repeat the next week. Switch over to the developer channel and you’ll get weekly OTAs.

MIUI is kind of a hybrid of Android and iOS. The most jarring change is the lack of an app drawer—like iOS, there is only the home screen, so every icon must live on the home screen somewhere. MIUI 6, like iOS 7, took a flat approach to UI design. Other than the Google apps—which ship with the Mi 4i outside of China—everything is reskinned.

We’ve already seen MIUI 6 on the Mi Note, but that version was based on Android 4.4 KitKat. The Mi 4i is one of the company’s first 5.0 Lollipop devices. As you can probably tell from having KitKat and Lollipop-based OSes that are both called “MIUI 6,” Xiaomi considers MIUI to be a separate entity from the underlying Android version. While MIUI was a fine alternative to KitKat, when it came time for a Lollipop version, the company just completely paved over all of Google’s Material Design improvements. Use MIUI and you’d never know the difference between KitKat and Lollipop, and that makes the OS feel dated—there are a lot of improvements in Lollipop that are gone in MIUI 6.

As far as we can tell, there is no multi-user support. The recent apps revamp, called “Overview,” doesn’t exist in MIUI. There’s no way to display multiple Chrome tabs, Drive documents, or any of the other new “document centric” multitasking from Lollipop. There’s no quick access to the priority notification modes the way there is in stock Android—they exist, but you have to dig through the settings app to change modes. There are no always-on-voice commands, no smart lock options, no battery saver mode, and no way to search the settings. Lollipop added the “Camera 2” API, which allows for manual ISO and exposure settings, but it’s not supported on the Mi 4i even with a third-party app. Message and call notifications don’t show contact pictures, and music notifications don’t show album art.

(Xiaomi Mi 4i:Review)

Besides the features that are outright missing, a lot of things are just inferior to the normal Lollipop design. The thumbnail view for recent apps shows full screen thumbnails, and it scrolls horizontally. This mean you get just two recent apps on-screen at a time. Lollipop has the common sense to scroll the list vertically—the direction in which you actually have screen real estate—and overlap the thumbnails, so you get four to five items on-screen at once. MIUI also has a weird quick settings implementation. You pull the notification panel down and then swipe right. Lollipop’s double-swipe-down to get to the quick settings panel feels a lot, well, quicker.

MIUI does have one or two advantages over stock Android. It already has a kind of selective permission system—you can set to have an allow/deny pop-up show up for access to your location, contacts, camera, and other device features. There are also lots of customization options, along with a theme system. Google will be catching up to MIUI with a selectable permissions system (along with lots more developer support) in Android M.

MIUI just hasn’t kept up with Android 5.0, making Xiaomi’s skin the biggest downside to using this device. Google revised the entire interface in Lollipop, and MIUI mostly ignores those improvements in favor of the same interface it had in KitKat. As a result, there are staggering amounts of missing features over stock Android.


We don’t dive into mid-range phones much, so the Mi 4i is the first device we’ve tested with the 64-bit Snapdragon 615. Like the Snapdragon 810 or 808, this is Qualcomm ditching its Krait CPU cores for an off-the-shelf solution from ARM, all in the name of 64-bit support (lower-end chips in the 400- and 200-series used 32-bit ARM CPU cores too, though). It’s an octa-core, big.LITTLE chip, where four powerful-but-power-hungry chips do the heavy lifting and four slow-but-efficient chips handle idle processing. The 810 took four Cortex-A57 cores for speed and four Cortex-A53 cores for efficiency, but in the 615, everything is a Cortex-A53. The speedy set is clocked at 1.7GHz and the efficient ones are clocked at 1GHz.

Again, Xiaomi is in a league of its own when it comes to bang-for-your buck. As mentioned earlier, the $179 Moto G is the closest major price competitor, but with a Snapdragon 400, it doesn’t stand a chance in a performance fight. Your other options for Snapdragon 615-powered phones are the Sony Xperia M4 Aqua—which, despite having a lower resolution screen and smaller battery, comes in at $110 more than the Mi 4i—and the HTC Desire 826—which has an extra half-inch of screen but chops 520 mAh off the battery for $168 more than the Mi4.

We have to compare the device to something, though, so we’re pitting it against the 2014 Moto G and its 1.2GHz quad-core Snapdragon 400 (so you can see just how badly it loses), the Samsung Galaxy S5 and its 2.5GHz Snapdragon 801 processor, and the $300 ASUS Zenfone 2 and its Intel Atom Z3580 processor.

Just like with all the other Xiaomi devices, the Mi4i is listed twice in the benchmarks, once in the default “balanced” power mode and again in the “performance” mode. From what we can tell, “Performance” pegs the processor at max frequency and never lets it turn down while idle. This is not a very good mode to ever run in. “Balanced” seems to be normal—max frequencies are available when needed, and the phone steps down to lower power modes when idling. This default mode is the one you want to run in.For our battery tests, we ran the Mi 4i in the default “Balanced” mode because “Performance” only really turns off idle low-power states, and you don’t need to run your phone that way all the time. In the Web browsing test, it does about as well at the Moto G (481 minutes versus 493 for the Moto G) and in the heavier WebGL test, it lasts for a very long time.

The Wi-Fi test score is a little disappointing with such a huge battery. Remember, the Moto G is doing much less work with only a 720p screen, and we’re guessing the Mi 4i is missing higher-end features like Panel Self Refresh—a power saving trick that puts (expensive) memory on the display, allowing the GPU to shut down if the on-screen image doesn’t need to be updated.


Low end smartphone cameras are usually exercises in pain, but we took some camera samples anyway. Again, the only device we have that should be comparable is the Moto G, but we’ve also unfairly pitted it against the $300 Asus Zenfone 2 and the $650 Galaxy S6. You shouldn’t care too much about camera megapixels, but the Mi 4i has a 13MP sensor.

Anyone have a stock Android ROM?

The Mi 4i, as usual for a Xiaomi device, provides outstanding value. $200 for a 5-inch 1080p device with a Snapdragon 615 and lots of trimmings: LTE, Quick Charge 2.0, and 2 SIM slots. The build quality is excellent for a $200 device, and it’s hard to find a spot where the company cut a corner. The only thing it’s really missing is NFC.

The software is a bummer, though. This is one of Xiaomi’s first Lollipop devices, and the company’s skin just hasn’t kept up with stock Android. The Android L preview launched a year ago. We would think that would be plenty of time for Xiaomi to nail down things like multi-user support, the camera 2 API, quick access to notification modes, and a comparable recent apps interface, but none of that is present here. Xiaomi will fix this eventually—it’s hard not to when you have a weekly development cycle—but for now the skin is lagging behind. This device is still running MIUI 6, which originally launched on KitKat, so we’re guessing that MIUI 7 will integrate a lot of these Lollipop features.

For now, we have a phone with definitively better specs than the current low-price champ, the Moto G, but the Mi 4i offers worse software. Normally it would be a tough decision if both of these phones were equally easy to buy, but Xiaomi only sells phones in China, India, and a handful of other territories. For now, the decision has been made for us.

The Good

  • Outstanding value for money.
  • Great build quality and a matte, hard plastic shell that makes the phone feel like it’s worth a lot more than $200.
  • Lots of extra that aren’t guaranteed on a phone this cheap. You get LTE and Qualcomm Quick Charge 2.0.
  • A very big 3120 mAh battery.

The Bad

  • MIUI was fine when it was replacing KitKat, but as an alternative to Lollipop’s Material Design, it feels dated. Everything has been paved over with the KitKat-era UI, so a lot of features are missing.
  • It still—still—has a menu button symbol. It doesn’t work like a menu button anymore. It opens recent apps, but the button symbol never changed.
  • We still don’t like these weird micro-USB A/B ports.

The Ugly

It’s a Xiaomi device, so you can’t buy one in many countries.

Source:Ars Technica


  • Display 8
  • Build8
  • UI5
  • Performance9
  • Battery8
  • 7.6