ZUK Z1 by Lenovo review: The second cousin

Display

The ZUK Z1 has a 5.5" 1080p screen, which under Chinese influence has been turning into the the new golden midrange standard. At 401ppi the screen is sharp and doesn't tax the chipset or the battery like QHD would have.

Resolution aside, ZUK did plenty to optimize image quality. We measured the screen at 396 nits and a contrast of about 1,000:1, which is average.

An Outdoor mode (which can be triggered automatically) changes the screen settings, allegedly to make the screen more legible in the sun. We appreciate the hardware solution more - a polarizing filter that further improves legibility (similar to the ClearBlack tech we've seen on Lumias).

Sunlight contrast ratio

• Nokia 808 PureView
  4.698
• Samsung Galaxy S6 edge+
  4.615
• Samsung Galaxy E7
  4.485
• Samsung Galaxy A3
  4.241
• Samsung Galaxy S6 edge
  4.124
• Samsung Galaxy S6
  4.124
• Samsung Galaxy Note5
  4.09
• Samsung Galaxy Note 4
  4.033
• Apple iPhone 5
  3.997
• Samsung Galaxy Note 3
  3.997
• Samsung Galaxy A5
  3.895
• Samsung Galaxy J7 outdoor
  3.879
• Samsung Galaxy A8
  3.859
• Apple iPhone 6
  3.838
• Motorola Moto X (2014)
  3.816
• Samsung Galaxy Note Edge
  3.799
• Apple iPhone 6s
  3.783
• Vivo X5Pro
  3.706
• Samsung Galaxy A7
  3.679
• Oppo R5
  3.678
• Samsung Galaxy K zoom
  3.675
• Nokia Lumia 930
  3.567
• Apple iPhone 5s
  3.565
• Samsung Galaxy S5
  3.549
• Nokia Lumia 735
  3.547
• Motorola Nexus 6
  3.543
• Apple iPhone 6s Plus
  3.53
• Alcatel Idol X+
  3.527
• Apple iPhone 5c
  3.512
• Samsung Galaxy Alpha
  3.509
• Oppo R7 Plus
  3.499
• Samsung Galaxy Note 3 Neo
  3.487
• vivo X5Max
  3.472
• LG G Flex2
  3.465
• YotaPhone 2
  3.453
• Samsung Galaxy J7
  3.422
• Motorola RAZR MAXX
  3.42
• Samsung I9300 Galaxy S III
  3.419
• Meizu MX5
  3.416
• Samsung Galaxy S5 Active
  3.406
• Nokia Lumia 925
  3.402
• Gionee Elife S5.5
  3.386
• Samsung I9505 Galaxy S4
  3.352
• Oppo R7
  3.32
• Samsung Omnia W
  3.301
• Samsung Galaxy S5 mini
  3.174
• Samsung I9000 Galaxy S
  3.155
• Samsung Ativ S
  3.129
• Samsung I9190 Galaxy S4 mini
  3.127
• Samsung Galaxy S4 zoom
  3.118
• Nokia N9
  3.069
• Microsoft Lumia 640 XL
  3.065
• Apple iPhone 6 Plus
  3.023
• Samsung Galaxy Note
  2.97
• Samsung Galaxy Premier
  2.958
• Sony Xperia Z1
  2.95
• HTC One S
  2.901
• Lenovo S90 Sisley
  2.892
• Samsung I8730 Galaxy Express
  2.861
• BlackBerry Q10
  2.856
• Samsung I9100 Galaxy S II
  2.832
• Sony Xperia Z3+
  2.824
• HTC Desire Eye
  2.815
• Gionee Elife S5.1
  2.812
• Samsung Galaxy S II Plus
  2.801
• BlackBerry Z30
  2.79
• Sony Xperia Z5 compact
  2.784
• Meizu MX4 Pro
  2.765
• Sony Xperia M5
  2.69
• Sony Xperia ZR
  2.672
• Huawei Ascend P1
  2.655
• Xiaomi Mi 4i
  2.641
• Sony Xperia Z3
  2.618
• Sony Xperia Z3 Compact
  2.616
• Sony Xperia T3
  2.609
• BlackBerry Passport
  2.595
• Microsoft Lumia 640
  2.563
• Nokia Lumia 900
  2.562
• Motorola Moto G 4G
  2.546
• HTC One Max
  2.537
• Nokia Lumia 720
  2.512
• HTC One
  2.504
• Sony Xperia M4 Aqua
  2.503
• Motorola Moto G
  2.477
• vivo Xshot
  2.465
• Sony Xperia Z
  2.462
• Xiaomi Mi 4
  2.424
• Samsung Galaxy S III mini
  2.422
• Lenovo Vibe Z2 Pro
  2.416
• LG G Flex
  2.407
• Huawei Honor 7
  2.406
• ZUK Z1 by Lenovo
  2.382
• HTC Desire 820
  2.372
• HTC One (M8)
  2.371
• Meizu MX4
  2.366
• Motorola RAZR i
  2.366
• Meizu m1 note
  2.362
• Sony Xperia ZL
  2.352
• HTC One M9
  2.334
• LG G4
  2.317
• Samsung Galaxy Note II
  2.307
• HTC One E9+
  2.305
• HTC One (M8) for Windows
  2.291
• Oppo R1x
  2.281
• Oppo Find 7a
  2.279
• Alcatel One Touch Hero
  2.272
• Apple iPhone 4S
  2.269
• HTC Desire 600 dual sim
  2.262
• Sony Xperia C5 Ultra
  2.253
• Nokia Asha 311
  2.25
• Sony Xperia C4 Dual
  2.235
• Xiaomi Mi Note
  2.234
• Motorola Moto G (2014)
  2.233
• LG Nexus 5
  2.228
• Huawei P8
  2.196
• Nokia Lumia 820
  2.193
• HTC One (E8)
  2.185
• Oppo N3
  2.181
• Nokia Lumia 920
  2.17
• Huawei Honor 6
  2.169
• Xiaomi Redmi Note 2
  2.166
• OnePlus Two
  2.165
• HTC One X
  2.158
• Asus Zenfone 2 ZE551ML
  2.149
• LG Aka
  2.145
• Nokia N8
  2.144
• Nokia Lumia 620
  2.142
• Nokia 515
  2.134
• Archos 50 Diamond
  2.134
• HTC Desire 500
  2.129
• Sony Xperia C3 Dual
  2.12
• Xiaomi Redmi Note
  2.119
• Sony Xperia acro S
  2.119
• Nokia Lumia 1020
  2.103
• Oppo Find 5
  2.088
• Sony Xperia SL
  2.078
• Huawei P8lite
  2.078
• Nokia Lumia 630
  2.056
• BlackBerry Z10
  2.051
• Moto G 3rd gen max manual
  2.026
• Huawei Ascend Mate7
  2.024
• Samsung I9295 Galaxy S4 Active
  2.022
• Apple iPhone 4
  2.016
• HTC One mini
  2.003
• Xiaomi Mi 3
  2.001
• Huawei Ascend P7
  1.992
• LG G2
  1.976
• Sony Xperia E4g
  1.972
• OnePlus One
  1.961
• Oppo R819
  1.957
• Sony Ericsson Xperia ray
  1.955
• Lenovo Vibe X2
  1.952
• Sony Xperia Z2
  1.944
• Sony Xperia E3
  1.943
• Nokia Lumia 1320
  1.941
• HTC One mini 2
  1.94
• Samsung Galaxy Camera
  1.938
• Samsung Galaxy Grand Prime
  1.935
• Sony Xperia J
  1.932
• Acer CloudMobile S500
  1.931
• ZTE Blade S6
  1.927
• LG Nexus 4
  1.926
• LG G Pro 2
  1.922
• Samsung Galaxy Mega 6.3
  1.913
• Nokia Asha 308
  1.911
• HTC Butterfly 2
  1.905
• Sony Xperia T
  1.894
• Meizu m2 note
  1.892
• BlackBerry Leap
  1.892
• Nokia Lumia 830
  1.887
• HTC Desire X
  1.878
• HTC Windows Phone 8X
  1.873
• HTC Butterfly
  1.873
• HTC Butterfly S
  1.867
• Huawei Ascend P6
  1.865
• Huawei Ascend Mate
  1.845
• LG G2 mini
  1.838
• LG G3
  1.82
• Nokia Lumia 1520
  1.813
• HTC Desire 616 dual sim
  1.797
• Sony Xperia V
  1.792
• HTC Desire 816
  1.783
• Sony Xperia Z1 Compact
  1.772
• HTC Desire 700 dual sim
  1.769
• ZTE Nubia Z9 mini
  1.759
• Sony Xperia U
  1.758
• Meizu MX3
  1.754
• LG Optimus G
  1.753
• Sony Xperia T2 Ultra
  1.74
• Sony Xperia Z3 Tablet Compact
  1.735
• Acer Liquid Jade S
  1.734
• Sony Xperia SP
  1.733
• Oppo Find 7
  1.691
• LG Optimus 4X HD
  1.691
• HTC One V
  1.685
• BlackBerry Q5
  1.682
• LG Optimus Vu
  1.68
• Motorola Moto E (2nd Gen)
  1.675
• Xiaomi Mi Pad 7.9
  1.672
• LG Optimus GJ
  1.666
• ZTE Nubia Z9
  1.659
• LG Optimus 3D Max
  1.658
• HTC Desire V
  1.646
• Samsung Galaxy Xcover 2
  1.632
• Samsung Galaxy Ace 3
  1.622
• Microsoft Lumia 532
  1.615
• Jolla Jolla
  1.605
• Microsoft Lumia 435
  1.598
• Sony Xperia Z Ultra
  1.578
• Sony Xperia go
  1.577
• Samsung Galaxy Ace 2 I8160
  1.566
• Samsung Galaxy Core
  1.563
• LG Optimus G Pro
  1.552
• Motorola Moto E
  1.545
• LG Optimus 3D
  1.542
• Nokia Asha 302
  1.537
• Samsung Galaxy Core Prime
  1.507
• BlackBerry Curve 9320
  1.488
• Sony Xperia M
  1.473
• Oppo N1
  1.47
• Sony Xperia E4
  1.467
• Meizu MX 4-core
  1.462
• Nokia Lumia 610
  1.432
• Samsung Galaxy S Duos
  1.4
• Samsung Galaxy Grand Neo
  1.393
• Sony Xperia M2
  1.393
• Microsoft Lumia 535
  1.393
• Samsung Galaxy Grand 2
  1.38
• Sony Xperia E1
  1.372
• Nokia Lumia 625
  1.371
• Gigabyte GSmart G1355
  1.361
• Sony Xperia L
  1.351
• Xiaomi Redmi 1S
  1.35
• Samsung Galaxy Mega 5.8
  1.35
• HTC Desire 510
  1.34
• Sony Xperia M2 Aqua
  1.331
• Sony Xperia miro
  1.324
• Samsung I9082 Galaxy Grand
  1.321
• Samsung I8530 Galaxy Beam
  1.315
• Xiaomi Redmi 2
  1.311
• HTC Desire C
  1.3
• Nokia X
  1.291
• Sony Xperia C
  1.283
• Nokia Asha 503
  1.281
• Nokia Asha 501
  1.27
• LG Optimus L7
  1.269
• Nokia Lumia 510
  1.268
• Samsung Galaxy Fame
  1.245
• LG Optimus L9
  1.227
• Meizu MX
  1.221
• Samsung Galaxy Young
  1.22
• Sony Xperia E
  1.215
• Nokia XL
  1.204
• Sony Xperia E dual
  1.203
• Asus Memo Pad 7 ME176C
  1.198
• Samsung Galaxy Pocket
  1.18
• Nokia Asha 305
  1.178
• Nokia Asha 306
  1.175
• Sony Xperia neo L
  1.169
• Sony Xperia tipo
  1.166
• Nokia Lumia 520
  1.161
• Samsung S6802 Galaxy Ace Duos
  1.148
• Samsung Galaxy mini 2
  1.114

Color rendering is fairly accurate (Avg deltaE 5.2 for the primary colors plus black and white), with white being not as accurate as we would expect. With a deltaE of 9.9, it's on the colder bluish side, but you would hardly notice that unless you get some sort of a reference to compare it side by side.

As usual, display colors are a matter of personal taste and perception so if you don't need calibrated color output, you will probably be quite happy with the color rendition on the Z1.

If you are not happy, Cyanogen OS offers plenty of ways to adjust the screen output. We managed to improve substantially the accuracy of the color rendition by adjusting the color temperature via the LiveDisplay feature from 6500K to 5200K. With this adjustment Avg deltaE went down to 3.8 and the rendition of white became almost perfect. The screen however loses some of its maximum brightness in the process and would only go as high as 383nits with this adjustment.

LiveDisplay lets you create two presets for color temperature - one for use during the day and one for night time. You can switch between day/night manually or have the phone do it automatically.

If you're wondering why, it's medical reports claim looking at blue light in the evening can affect your sleeping cycle. Several studies have confirmed that it reduces melatonin - the hormone responsible for sleep. So you might want to use a warmer light setting (i.e. less blue or smaller temperature reading) at night.

Connectivity

The ZUK Z1 is a dual-SIM, dual-standby phone that can freely roam the globe. It has basic GSM and CDMA connectivity, along with 3G data (again GSM and CDMA) and two flavors of LTE (international and Chinese).

Dual-band Wi-Fi a/b/g/n/ac is supported as is Bluetooth 4.1, however there's no NFC or ANT+. This precludes easy pairing and certain sports trackers. Positioning is handled by a GPS and GLONASS receiver.

The wired connectivity is the more interesting part. USB 3.1 Type C promises up to 5Gbps transfers, up from around 0.5Gbps for USB 2.0. While microUSB 3.0 did not last on mobile devices, Type C is building up popularity.

It doesn't look like ZUK has implemented some of the more advanced features of the standard - e.g. DisplayPort TV out and the 100W power delivery spec - but it definitely has the speed. We ran a couple of benchmarks with the Z1 connected to a USB 2.0 port and a USB 3.1 port and copied over a large file from the SSD on one of our office PCs.

We copied the file over several times to the ZUK Z1, first through a USB 2.0 port and then through a USB 3.0 port. The phone didn't max out either standard, but it ran noticeably faster on USB 3.0, especially when copying from the phone to the computer.

Note: the USB Implementers Forum renamed USB 3.0, which leads to some confusion. What used to be USB 3.0 is now "USB 3.1 Gen 1" while what was supposed to be USB 3.1 is marketed as "USB 3.1 Gen 2." Gen 2 doubles the speed of Gen 1, 10Gbps.

Battery life

The ZUK Z1 has a huge 4,100mAh Li-Ion battery. It's made up of two rectangular batteries stacked on top of each other to better fill in the curved shape of the back. Note that you don't get any special fast-charging solutions, the included 5V/2A charger is fast but will still take a while to fill up the battery.

You've probably heard that lithium batteries don't like being overcharged - leaving them plugged in when they are at 100% reduces their lifespan. The ZUK Z1 has a hardware solution to the problem, which disconnects the battery from the charger and run the phone on electricity from the charger. Other phones do the opposite - disconnect the charger from the battery, drain the battery a bit, charge it back up, which isn't good for the battery either.

With such a big battery, the big results come as no surprise. Talk time hovers around 25 hours, an excellent result (even if we expected more). In the browser test the Z1 came 15 minute short of 11 hours, again a good result without being the best. It lasted longer when playing videos, over 14 hours, which too falls in the great, but not perfect category.

Our proprietary score also includes a standby battery draw test, which is not featured in our test scorecard but is calculated in the total endurance rating.

The battery testing procedure is described in detail in case you're interested in the nitty-gritties. You can also check out our complete battery test table, where you can see how all of the smartphones we've tested will compare under your own typical use.