vivo X21 smartphone review: Stumbling out of the gate

Overview

They’re a bit late to the game in Singapore, but vivo has been launching phones at us in double quick time. Two months ago, we reviewed the V7+, its first phone to hit these shores. At the time, we found that alongside both its BBK Electronics brethren - Oppo and OnePlus - and numerous other competitors at its SRP of S$469, the V7+ did everything acceptably well - but not given that price point.

But as a certain Billy Joel once sang, “don’t forget your second wind”. Will the breeze blow in for vivo now that the all-new X21 has appeared? Lest you feel inclined to ask why, this phone actually has something to crow about: the world’s first implementation of an in-display fingerprint sensor. As well, it packs way better tech than the budget-class V7+. Hope springs eternal!

(Oh, and in case you’ve forgotten, the Chinese brand is not incorrectly spelled - it is styled in lowercase.)

Design

vivo Singapore tried to convince us previously that vivo is an independent company with no relation to BBK Electronics of Dongguan, China. Certainly, placing the X21, the Oppo R15 Pro, and the OnePlus 6 side-by-side for inspection (which we are unfortunately unable to do) should reveal nothing at all. See, the cameras are in different places! I told you: not same company!

Anyway, the X21 has a clean glass-on-metal design that, apart from the “Designed by vivo” text on the back (why? It can’t have been designed by Apple, right?) is quite appealing, though in the time it takes for Ready Player One to throw out pop-culture references, the vivo would have picked up more fingerprints. The display on the front continues with the good impressions: it’s easy on the bezels, with a 6.28-inch diagonal and a Full HD+ resolution (2,280 x 1,080 pixels) - and it’s a Super AMOLED panel at that. Oh, and it looks pretty good outdoors, too:

Alles klar so far. Then you take a look at the bottom of the phone, and that’s where the X21 first stumbles. On a phone costing a dollar short of S$800 - a micro-USB charging and data port. Seriously? Hoping for stereo speakers to soothe the burn, you glance to its left and right. Nope, there’s only one, and it’s an abysmal one at that too, with muddy midtones and virtually no bass to speak of.

Surprisingly, the “3-choose-2” SIM and microSD card tray is also on the bottom of the phone. The internal storage of 128GB (good on you, vivo) is therefore expandable to 256GB with an extra memory card. Our eagle eyes spotted an O-ring around the SIM tray, and we wondered if, like the OnePlus 6 and Oppo R15 Pro, the X21 was not secretly water resistant? (Note: vivo hasn’t said anything, so leave the shower karaoke to other phones.)

Now, over to the top: there’s actually a headphone jack. At this point, we’re utterly confused - should the vivo X21 be priced more sensibly, in line with this mix of mid-range and budget specifications? Or is there some killer feature that will justify the asking price?

At least we must give kudos to Chinese manufacturers for shipping protective cases or bumpers with their phones to get you started - vivo has done that with the X21, and it’s a rather elegant polycarbonate case, at that. South Koreans, Japanese, Americans: we hope you’re listening…

About that in-display fingerprint sensor...

The vivo X21 is among the first (well, actually the second, after the vivo X20 UD) smartphones to feature an in-display fingerprint sensor, which should function in this manner when it does work:-

The sensor is made by Goodix, a Shenzhen-based outfit which also supplies conventional fingerprint sensors and touch panels to Huawei, Xiaomi, Nokia and a whole host of other brands.

As far as we can tell, the technology works not in a capacitive manner as standard fingerprint sensors do, but by capturing reflected light between the OLED pixels (it only works with OLED displays for this reason, as LCD displays would have a backlight layer.) Goodix claims that its in-display sensor has a 2% false rejection rate, and works faster than capacitive sensors.

Unfortunately, at least in the vivo X21, we found that these claims didn’t seem to hold water…

First off, in case you were wondering, this is an in-display fingerprint sensor, not a display-wide fingerprint sensor. The phone will indicate on the display, with an animated fingerprint icon, exactly where the screen must be touched (or rather, pressed - more on this later) to unlock it. If the display is off, the icon will appear only when the X21 is moved or picked up, which can actually be hugely annoying: if you’re driving, the phone will be snugly ensconced in a car mount, and what then? You’ll have to resort to pressing the power button to bring up the icon, whereas phones with conventional fingerprint sensors will unlock immediately the moment their sensors are touched.

Now, all of this might be forgivable, especially that screen-off issue, if the sensor itself was fast and reliable. Here’s the bad news: it’s emphatically not.

To begin with, the unlock process - when it works - is far from lightning-fast, as on a OnePlus or Huawei device; the sensor takes something like a second and a half to recognize a finger - that is, when it wants to. In the time we spent with the phone, it was very safe to say that we ran out of tries and had to enter the unlock PIN way more times than we got a fingerprint to unlock it. In fact, it’s also safe to say that we entered the PIN more times on the vivo X21 than on all our previous phones (with conventional fingerprint sensors) combined.

In a futile week of tests, we enrolled and tried all the fingers we had, tested wet and dry fingers, sweaty palms and all, and even tried to pin down whether high ambient light levels and/or low display brightness would cause unlock failure (the phone appears to mitigate this by illuminating the touch zone in bright cyan, no matter what the display brightness is set to.) The sensor appears to be sensitive to dirt - this writer pressed it to his oily face a few times to test this, and the result was complete failure to unlock until the screen was cleaned. Indeed, it appears to be so finicky that vivo even warns that third-party screen protectors may interfere with its operation.

Certainly, having the sensor in the display saves space, and vivo deserves credit for jumping into the game of 'Innovations That Are Not Gimmicks', but as it stands, we’re not sure this technology is really ready for prime time. If the X21 is on your shopping list, you should actually test out the sensor for yourself on vivo’s in-store display phones, and be at least prepared for an experience similar to ours in real-world usage.

Software

We’ve covered Funtouch OS in our vivo V7+ review, and the X21 serves up more of the same. In this case, it’s based on Android 8.1 Oreo, which thankfully brings one major change: notifications are coalesced in the notification shade, hurrah!

But no, there are still no quick settings in the notification shade…

Any hope that Oreo would have thrown some cookies to owners of newer vivo phones crumbled as we leafed through the pages:

It’s all there: the Chinglish and half-completed text strings, the same mix of loud and excruciatingly detailed alternating lock screen wallpapers, those skeuomorphic icons, and the inexplicable choice of bloatware (because paying for an X21 would leave me change out of S$800 for an ofo ride home?)

We think that vivo doesn’t need to ape Samsung or Huawei. But we also said in the V7+ review that that phone would have been better served with a stock build of Android, which would immediately have helped its high-powered cameras overshadow its weak processor. Likewise, the X21 could be really, really great with Android One. Think about it, vivo.

Finally, it's worth noting that the X21 doesn't have an NFC chip, which is a major surprise for a phone that costs S$799. That means you won't be able to use it for any mobile payment apps like Google Pay and the amazing number of contactless payment options available these days. What a pity.

Benchmark Performance

Thankfully, the vivo X21 gives pretty good face in its choice of processor. The Qualcomm Snapdragon 660 is best thought of as a “poor man’s 820”, with Kryo instead of vanilla ARM Cortex cores and a modern 14nm process that work out to performance surprisingly close to the aforementioned previous-generation chip.

Along with the only other Snapdragon 660 powered device we’ve tested - last year’s ASUS Zenfone 4 - we’ll throw the new ASUS ZenFone 5 (ZE620KL), priced at S$488 SRP and based on the slightly slower-clocked Snapdragon 636, into the fray along with the Samsung Galaxy A8+ (2018), which has an Exynos 7-series processor as well as very similar specs and SRP.

Sunspider Javascript

First up: SunSpider, which measures JavaScript processing performance. SunSpider takes into consideration not just the underlying hardware performance, but how optimized a particular platform is in delivering a high-speed web browsing experience. The X21 produced performance in line with the Samsung, which is in its price range, but somehow slower than the ZenFone 4. The ZenFone 5 trailed by quite a significant margin thanks to its slower-clocked 636:

3DMark Sling Shot

3DMark Sling Shot Unlimited 3.0 uses a mix of graphics and physics tests to measure hardware 3D performance. What is interesting here is that the vivo X21 - despite the Adreno 512 GPU in the Snapdragon 660 being known to be more powerful than the ARM Mali-G71 MP2 in the Exynos 7885 - merely keeps pace with the Galaxy, and trails the ZenFone 4. We put this down to software optimizations that could have been improved, perhaps.

Basemark OS II

BaseMark OS measures overall system performance over a number of different metrics. Here, since both the Exynos 7885 and Snapdragon 660 chips have 8 cores clocked at up to 2.2GHz, the vivo X21’s victory is almost certainly due to its eight all-Kryo core setup being more powerful than the mixed 2x Cortex-A73/6x A53 blend in the Samsung:

Imaging performance

The vivo X21 is equipped with a dual-camera setup. The main cameras are made up of a 12-megapixel f/1.8 and a 5-megapixel f/2.4 duo. If you were hoping that this might be similar to the “normal-plus-wide-angle” setups found on LG phones: sorry. Given the incredibly small aperture and resolution of the 5-megapixel unit, this might be a blessing in disguise. At least the 12-megapixel unit has 1.4µm pixels - though it lacks OIS (optical image stabilization). Come on, vivo, this thing is almost S$800…

The camera interface features a Professional mode with shutter speeds up to 32 seconds. While there’s 4K video recording, it only happens at 30fps.

Let’s cut to the chase: the X21’s images are decently sharp and pleasing in good light - but the praise ends there, given that a ton of other phones with 12MP large-pixel sensors, some of which (*cough* Redmi 5 Plus *cough*) cost several hundreds of dollars less, will also deliver the goods.

Dual-camera bokeh on the vivo X21 isn’t all that great either, with the algorithm making some howlers from time to time (check out the red line just above the players’ heads on the image below:)

Smartphone makers invariably like to leave out OIS to cut costs, and some would argue that this is also done on even the most pricey phones, such as the north-of-S$1,000 Google Pixel 2 XL. But the Pixel has Google’s wicked multi-frame noise-reduction trickery to rely on, while most other manufacturers are left with the unsavory option of raising the ISO in low light, which results in images that may not be blurred - but are otherwise soft, or noisy, or both.

Be warned, then: the vivo X21 is not the kind of phone you would want to bring to concerts, or for a night stroll in the city. In such situations, shots get rather noisy, making for softness and color casts:

The vivo X21 has a 12-megapixel f/2.0 front selfie shooter, but the less said about it, the better. Check out this incredibly overexposed mug:

Battery Life

Finally, here’s our standard battery test, which involves:

• Looping a 720-pixel video with screen brightness and volume at 100%
• Wi-Fi and Bluetooth connectivity turned on
• Constant data streaming through email and Twitter.

While the vivo’s battery is almost on par with the cells in the ZenFone 4 and 5 (3,200mAh vs 3,300mAh in the ASUS phones), the Galaxy A8’s larger 3,500mAh cell is clearly not the only thing responsible for the jump of more than 4 hours from the three Snapdragon-powered devices. The all-Kryo core setup is a double-edged sword here, drinking far more battery juice no matter how you slice it, while the Galaxy A8+ can turn off its power-hungry A73 cores and let the A53s do the work.

In real-world use, the battery performance wasn’t great either. With infrequent web browsing and some heavy texting during lunch and dinner times, we could make it through a workday with careful control over display brightness. If the camera was in use - or if someone decided to serve up, say, a chicken dinner in PUBG Mobile - things went south pretty quickly, and we found ourselves reaching for the charger by tea time.

Speaking of charging, the X21 supports fast charging via something termed a “Dual-Charging Engine”, which appears to be proprietary to vivo. A quick and dirty test at 78% saw the battery juiced up to full charge in somewhat under half an hour, at around 2 amps:

Conclusion

Once again, the vivo X21 seems to us like another strange concoction from BBK. For a device priced very close to the flagships, it doesn't have NFC functionality, the camera lacks OIS, doesn’t do wide angle photography, and doesn’t zoom very well either. It has a slightly smaller battery than its almost identically-specced Oppo sibling, the R15 - which costs S$50 less. And it uses a micro-USB port in 2018.

After wringing our brains out, here’s what we conclude: If you need a phone that packs lots of storage, like AMOLED displays (but always watch YouTube vids with earphones), love the idea of the in-display fingerprint scanner technology (when it does work), and don’t mind the somewhat chintzy look of Funtouch UI, the vivo X21 can be in your consideration list.

But then you remember that for some S$300 less, the 2018 refresh of the ASUS Zenfone 5 offers dual cameras that do both wide-angle and bokeh, with just a slightly slower-clocked Snapdragon 636 - and in fact, you can even have dual-camera action on the Android One-based Mi A1 at S$349. On the other side of the scale, you also remember that for S$100-200 more (street pricing), you could add any of the following extremely tasty sides: dual-aperture cameras from the 64GB variant of the Samsung Galaxy S9 Plus, or a 40-megapixel triple-camera setup and gobsmackingly good night shots from a Huawei P20 Pro. In fact, as of the time of writing, some stores were actually selling the Huawei Mate 10 Pro for as low as S$780 - and this is a phone that bests the X21 in almost every regard, with perhaps the exception of the headphone jack.

When the dust settles on its world-first fingerprint sensor technology, the vivo X21’s SRP of S$799, coupled with average specifications, makes for a tough sell. Bring it down to S$500 or so - more in line with the Honor devices - and put stock Android on it, and it would be a far more interesting device.

We’re waiting, vivo...

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