Notebookcheck

Lenovo Yoga Book C930 (i5-7Y54, LTE, E-Ink) Convertible Review

Christian Hintze, 👁 Sebastian Jentsch (translated by Katherine Bodner), 12/24/2018

3-in-1 convertible. The new Yoga Book has an E-Ink display instead of a keyboard and can be considered a combination of a laptop, a tablet and an e-reader. On top of that, you can also digitalize text and drawings with this all-rounder. The device is based on its predecessor from 2016 but offers many changes and improvements. For instance, it provides better performance. On the other hand, it has also dropped at least one feature. Is the 2018 Yoga Book worth twice the price of the old version? Find out in our detailed review.

The first Lenovo Yoga Book appeared in 2016 and attracted attention with its unique feature: Instead of a keyboard, the 360-degree convertible was equipped with a touch surface that covered the base unit. This could be used as a virtual keyboard or as a drawing board on which users could clip a piece of paper and take notes or draw with the included pen. The inputs would then be digitized.

The new Lenovo Yoga Book C930 - not to be confused with the Lenovo Yoga C930 (without the "Book") - has reinvented itself. Instead of the touch surface, we are now treated to a second screen - an E-Ink display with 1080p resolution. The paper holder has been removed. Instead, the E-Ink display can be used for typing, drawing, writing and even as an energy-efficient e-reader.

We at Notebookcheck encountered a very particular difficulty: This very special device is so unique that it can hardly be compared with any other notebook, tablet or convertible. Therefore, we chose both convertibles and tablets as our comparison devices. These include the Microsoft Surface Pro (2017), equipped with the slightly weaker m3 processor (also an option for the Yoga Book), the Huawei Matebook E and the Lenovo ThinkPad X1 Tablet Gen with the same CPU. Of course, we also compared the current test unit with its predecessor.

The only real weaknesses of the first Yoga Book were the small port selection as well as the slow eMMC storage. At least the latter has now been replaced by an NVMe SSD. We will discuss any other differences and whether the Yoga Book can be recommended in this review.

We do want to highlight another difference: The price. While the most expensive version of the predecessor cost around $600, Lenovo now charges $1050 for its Yoga Book. We would expect a lot of useful improvements and changes for this drastic increase in price. Currently, there is only one version available in the US. This is equipped with a Core i5 processor and a 128-GB SSD.

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Lenovo Yoga Book C930 YB-J912F (Yoga Book Series)
Graphics adapter
Memory
4096 MB 
, DDR3-1866
Display
10.8 inch 16:9, 2560 x 1660 pixel 283 PPI, capacitive, native pen support, BOE 0765, IPS, 360-degree tablet mode, glossy: yes
Mainboard
Intel Kaby Lake-Y Premium PCH
Storage
Toshiba KBG30ZMT256G, 256 GB 
, 196 GB free
Soundcard
Intel Kaby Lake-U/Y PCH - High Definition Audio
Connections
2 USB 3.0 / 3.1 Gen1, Card Reader: microSD, 1 Fingerprint Reader, Brightness Sensor, Sensors: accelerometer, ambient light sensor, Hall sensor, 2x USB-C 3.0
Networking
Intel 8265 Tri-Band WiFi (Oak Peak) Network Adapter (a/b/g/n/ac), Bluetooth 4.2, LTE
Size
height x width x depth (in mm): 9.9 x 261 x 179 ( = 0.39 x 10.28 x 7.05 in)
Battery
36 Wh Lithium-Polymer, Battery runtime (according to manufacturer): 8.5 h
Operating System
Microsoft Windows 10 Home 64 Bit
Camera
Webcam: FHD
Primary Camera: 2 MPix
Additional features
Speakers: Stereo, Keyboard: Virtual, Keyboard Light: no, E-Ink Mobius™ FHD-Display & Bluetooth-Pen, Microsoft OneNote, Lenovo Vantage, Microsoft RDX, Dolby Atmos, E Ink Keyboard, E Ink Note, E Ink Reader, E Ink Settings, 24 Months Warranty, fanless
Weight
778 g ( = 27.44 oz / 1.72 pounds), Power Supply: 100 g ( = 3.53 oz / 0.22 pounds)
Price
1500 Euro
Note: The manufacturer may use components from different suppliers including display panels, drives or memory sticks with similar specifications.

 

Case - Yoga 2-in-1

Like last time, Lenovo has chosen to cover its device with an aluminum/magnesium alloy. The non-slip surface offers a good grip - so much so that it almost feels "sticky". Overall, the device looks like it was sculpted from one mold. The display cover and bottom look equally thick. The missing physical keyboard means that the gap dimensions are very narrow. The two displays fold together almost seamlessly. The hinge is a little unusual and catches the eye. Apparently, it consists of 130 mechanical parts. Basically, it is made of tiny cogwheels that rotate in opposite directions and enable the convertible to open up to 360 degrees.

Although the material and simple exterior make the device appear very robust, the Yoga Book is sensitive to warping and the creaking noises it made during our attempts to bend it made us worry about the glass panels on the insides. We would avoid putting too much pressure on the case.

Of course, the Yoga can also be opened like a normal notebook, although this is made difficult by the narrow gap and the magnet that holds the two parts together. The knocking function is enough to impress any onlookers: You can open the display lid by knocking on it twice with your knuckles. The device then emits a quiet electronic noise and the convertible opens up enough for you to easily open it by hand. Alternatively, you can also press and hold the "volume down" button for the convertible to open up.

Front: The device is difficult to open alone, but a knock should help
Front: The device is difficult to open alone, but a knock should help

The insides consist of glass - both the upper touchscreen and the E-Ink display on the base unit have glass surfaces. Plastic borders are out. The base display has an integrated fingerprint reader in the top right corner. This should also work with wet fingers.

All our comparison devices have 12-inch screens, which is why they are all larger than the C930. In comparison to its predecessor, the new Yoga Book has grown slightly. Instead of 10.1 inches, it is now 10.8-inches large and 0.3 mm thicker. Although the competition might seem slimmer, this is not true, as the dimensions of the other convertibles were measured without their removable keyboard units. Therefore, the Yoga Book wins this category as well. The same can be said for its weight - only its predecessor was lighter. However, the weight differs depending on the equipment. Our test unit is positioned towards the top end of the spectrum. 

Size Comparison

Connectivity - stingy Lenovo Yoga Tablet

The limited port selection was one of the things we already criticized about the predecessor - and the same goes for its successor. Lenovo has made some changes, however. For example, the mini-HDMI port has been removed as well and the Micro-USB slot was replaced by two USB-C (Gen1) ports. Any external devices have to be connected via USB-C. As one of these ports will often be occupied by the power supply, there is only one connector available for devices such as a mouse, an external keyboard, monitors or any other (USB) devices. This is not ideal; the C930 really is more like a tablet in this regard. It does not even offer an audio jack, which means that headphones have to be connected via USB. Traditional laptop users will not be pleased with having only one or at the most two ports for all external devices. At least the C930 offers one USB slot more than its predecessor did. 

The device does not come with any adapters either (USB-C-to-audio-jack or HDMI, for example). Apart from the USB-C ports, the device has a power button and a physical volume rocker.

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Left: USB-C 3.1 (Gen1), LTE/MicroSD slot, speakers
Left: USB-C 3.1 (Gen1), LTE/MicroSD slot, speakers
Right: volume rocker, speakers, power button, USB-C 3.1 (Gen1)
Right: volume rocker, speakers, power button, USB-C 3.1 (Gen1)
Back: hinge
Back: hinge

SD Card Reader

There is an SD card reader available in the shape of an SD tray. However, the microSD card is placed in the same tray as the nano-SIM card (in the LTE version). The C930 has inherited this disadvantage of its predecessor. You will need to use the included pin to open the slot. This makes using the SD card overly complicated - particularly as the SIM card can apparently get damaged if it is removed during operation. To avoid this, turn off the device before inserting or removing a memory card.

The speed of the card slot is average according to our measurements with our reference card, the Toshiba Exceria Pro SDXC 64 GB UHS-II. 

SDCardreader Transfer Speed - maximum AS SSD Seq Read Test (1GB)
Lenovo ThinkPad X1 Tablet Gen 2
  (Toshiba Exceria Pro SDXC 64 GB UHS-II)
93.77 MB/s ∼100% +16%
Microsoft Surface Pro (2017) m3
  (Toshiba Exceria Pro M401 64 GB)
85.9 MB/s ∼92% +6%
Lenovo Yoga Book C930 YB-J912F
  (Toshiba Exceria Pro M501 microSDXC 64GB)
81.1 MB/s ∼86%
Average of class Convertible
  (24 - 246, n=108)
73.7 MB/s ∼79% -9%

Communication

The Yoga Book does not have a LAN card or slot, which means that users are dependent on wireless connections. The device can connect via Wi-Fi, Bluetooth and, in some cases, LTE. The Wi-Fi speed is average. The Matebook from Huawei is slightly slower while the Surface from Microsoft is a little faster. Overall, the Yoga Book performs slightly above average when receiving data and is significantly better than average when sending data. 

Networking
iperf3 Client (receive) TCP 1 m 4M x10
Lenovo ThinkPad X1 Tablet Gen 2
Intel Dual Band Wireless-AC 8265
586 MBit/s ∼100% +19%
Microsoft Surface Pro (2017) m3
Marvell AVASTAR Wireless-AC Network Controller
550 MBit/s ∼94% +12%
Lenovo Yoga Book C930 YB-J912F
Intel 8265 Tri-Band WiFi (Oak Peak) Network Adapter
491 (min: 446, max: 517) MBit/s ∼84%
Average of class Convertible
  (38.3 - 678, n=122)
482 MBit/s ∼82% -2%
Huawei Matebook E
Intel 8265 Tri-Band WiFi (Oak Peak) Network Adapter
437 MBit/s ∼75% -11%
iperf3 Client (transmit) TCP 1 m 4M x10
Microsoft Surface Pro (2017) m3
Marvell AVASTAR Wireless-AC Network Controller
655 MBit/s ∼100% +7%
Lenovo Yoga Book C930 YB-J912F
Intel 8265 Tri-Band WiFi (Oak Peak) Network Adapter
612 (min: 449, max: 687) MBit/s ∼93%
Huawei Matebook E
Intel 8265 Tri-Band WiFi (Oak Peak) Network Adapter
592 MBit/s ∼90% -3%
Average of class Convertible
  (39.2 - 685, n=122)
490 MBit/s ∼75% -20%
Lenovo ThinkPad X1 Tablet Gen 2
Intel Dual Band Wireless-AC 8265
440 MBit/s ∼67% -28%
0102030405060708090100110120130140150160170180190200210220230240250260270280290300310320330340350360370380390400410420430440450460470480490500510520530540550560570580590600610620630640650660670680690Tooltip
; iperf3 Client (receive) TCP 1 m 4M x10; iperf 3.1.3: Ø491 (446-517)
; iperf3 Client (transmit) TCP 1 m 4M x10; iperf 3.1.3: Ø612 (449-687)

Security

Fingerprint reader
Fingerprint reader

The C930 has a fingerprint reader that works reliably and combines well with Windows Hello. However, the reader replaces the second camera that the predecessor was equipped with. The device also has an accelerometer, an ambient light sensor and a Hall sensor. TPM is also included thanks to the Intel processor.

Camera

Camera: Bad quality
Camera: Bad quality

The predecessor was equipped with a normal low-quality camera and an additional 8-MP main camera with auto focus. This was removed in favor of the new E-Ink display and fingerprint reader, which leaves us with the standard 2-MP low-quality camera for video calls.

Accessories

The device comes with a power supply and an input pen with 4096 levels of pressure as well as a battery. We also received a quick-start guide and a pin to open the SIM/SD tray.

Maintenance

The maintenance options are dealt with quickly - there simply are none. Again, the device is more similar to a tablet than a notebook. 

Warranty

The manufacturer offers two-year warranty ex-works.

Input Devices - an unconventional Lenovo

Keyboard

Instead of a physical keyboard, the Yoga Book has an E-Ink display with 1080p resolution on which a virtual keyboard can be displayed. There are two layout versions available - classic and modern. Of course, there is no normal feedback when hitting a key on the screen. Therefore, the panel vibrates and emits a clicking sound when a key is pressed. Both these feedback versions can be deactivated in the settings. The 11-inch design does not offer a lot of space for the keyboard. The modern layout offers slightly larger letter keys - instead, all the other keys (shift, Ctrl, etc.) are squeezed together at the edge.

Two keyboard layouts. The space bar and touchpad share the same area in the modern layout.
Two keyboard layouts. The space bar and touchpad share the same area in the modern layout.

According to Lenovo, inputs are evaluated and then optimized by artificial intelligence. Apparently, this should improve typing productivity by 22% compared to its predecessor. The tactile feedback makes it quite comfortable to write on the keyboard, although users might want to connect an external keyboard for writing long texts, particularly as the artificial vibrating and clicking sounds can get rather annoying after a while.

Another disadvantage of the E-Ink display is its missing backlight. The keyboard is very easy to read in daylight, but users might miss the lighting in dark surroundings. The predecessor was not equipped with an E-Ink display but had a touch surface that was illuminated.

Touchpad

Touchpad: Small and narrow
Touchpad: Small and narrow

The touchpad that is displayed with the keyboard is not very impressive. On the one hand, it is very small, which means that you quickly reach or even cross over the edges when gliding over it. As the keyboard is displayed on one (display) surface, you can easily miss the designated touchpad area and click one of the surrounding keys by mistake. This causes the tablet to vibrate and make a clicking sound.

The touchpad has to share its space with the space bar - at least when using the "modern" layout. This means that either the space bar or the touchpad is displayed depending on the situation. In practice, you have to click a circle below the space bar for the touchpad to appear. As soon as you press a random key, the touchpad switches back to being a space bar. This can be extremely bothersome when you want to copy/paste or use one of the special keys (for example for volume) but then want to continue using the touchpad, which then has to be reactivated manually. It would be more useful if the space bar didn't reappear automatically but also required a manual change.

When using the "classic" layout, the touchpad is always visible but is a lot smaller. Apart from this, the gliding properties and precision are quite good. Only the limited size and problem with the space bar spoil the potentially good properties of the touchpad.

Input with precision pen

You can choose what the E-Ink display should be used for at the top of the base screen, as it not only acts as a keyboard but also acts as an e-reader or for inputs using the pen. If you choose pen input, an empty graphics tablet with a few options is displayed. Here you can write or draw to your heart's desire, using either the included input pen, which recognizes 4096 levels of pressure and transmits data via Bluetooth, or using your fingers. 

Unfortunately, the C930 also lacks some of the predecessor's functions. Particularly the possibility of drawing on paper is not officially supported anymore. This was one of the unique selling points of the 2016 model. Therefore, there is no paper holder and the pen no longer includes actual ink tips. Users are now limited to drawing directly on the E-Ink display or the touchscreen. The E-Ink display automatically straightens out writing after a few seconds. Nonetheless, the smooth glass surface is a lot more difficult to write on than paper. 

We did not find any options for automatically transferring the drawing to a certain program. The E-Ink picture can only be copied into different software (for example image-processing software).

E-Ink: a keyboard, a surface for drawing or writing or an e-reader
E-Ink: a keyboard, a surface for drawing or writing or an e-reader
Input pen
Input pen

Touchscreen

The Yoga Book has a very large number of input options. Apart from the keyboard and touchpad and the input pen for the E-Ink display, the main screen also supports inputs via touch. Operating the main display with the finger works very well and the panel is very precise. Only the small display size combined with a high resolution can make inputs difficult as you have to be rather precise to click on the small buttons correctly. Usually this works very well anyway. If you need more precision, you can also use the included pen on the touchscreen.

Naturally, you can also draw on the touchscreen, but as the E-Ink display is available simultaneously and in a better position, drawing and writing on that is simply more comfortable.

Display - brilliant Yoga Book

Pixel array
Pixel array
Basically no backlight bleeding
Basically no backlight bleeding

We rightly praised the Full HD main screen of the predecessor; the current test unit tries to go another step further. Instead of Full HD we now have a resolution of 2560x1600 pixels. Unfortunately, the brightness of the reflective display has diminished slightly and gone from 362 cd/m² in the predecessor to 338 cd/m² in the current model. We did not measure the 400 cd/m² the manufacturer claims for this display. Instead, the panel has improved in other areas. 

Particularly the black value and contrast of the current model have improved significantly. The Yoga Book C930 can even beat the Microsoft Surface Pro (2017) with a black value of 0.23 and a contrast ratio of 1526:1. There is hardly any backlight bleeding either.

364
cd/m²
327
cd/m²
315
cd/m²
342
cd/m²
351
cd/m²
332
cd/m²
329
cd/m²
338
cd/m²
344
cd/m²
Distribution of brightness
X-Rite i1Pro 2
Maximum: 364 cd/m² Average: 338 cd/m² Minimum: 6.3 cd/m²
Brightness Distribution: 87 %
Center on Battery: 351 cd/m²
Contrast: 1526:1 (Black: 0.23 cd/m²)
ΔE Color 4.59 | 0.4-29.43 Ø6.2, calibrated: 3.26
ΔE Greyscale 5.2 | 0.64-98 Ø6.4
100% sRGB (Argyll 3D) 74% AdobeRGB 1998 (Argyll 3D)
Gamma: 2.41
Lenovo Yoga Book C930 YB-J912F
BOE 0765, , 2560x1660, 10.8
Microsoft Surface Pro (2017) m3
LG Display LP123WQ112604, , 2736x1826, 12.3
Huawei Matebook E
Chi Mei CMN7801, , 2160x1440, 12
Lenovo ThinkPad X1 Tablet Gen 2
LSN120QL01L01, , 2160x1440, 12
Lenovo Yoga Book 2016 Windows 64GB LTE
nicht auslesbar, Farbgamut: 70% lt. Hersteller, , 1920x1080, 10.1
Response Times
-1%
30%
25%
8%
Response Time Grey 50% / Grey 80% *
43 (23, 20)
42 (20, 22)
2%
26 (10, 16)
40%
28.4 (15.2, 13.2)
34%
36 (18, 18)
16%
Response Time Black / White *
27 (13, 14)
28 (18, 10)
-4%
22 (12, 10)
19%
22.8 (13.6, 9.2)
16%
27 (6, 21)
-0%
PWM Frequency
221.2 (49)
Screen
10%
-2%
-14%
-2%
Brightness middle
351
461
31%
439
25%
388.1
11%
382
9%
Brightness
338
444
31%
428
27%
344
2%
363
7%
Brightness Distribution
87
93
7%
92
6%
78
-10%
83
-5%
Black Level *
0.23
0.34
-48%
0.35
-52%
0.39
-70%
0.37
-61%
Contrast
1526
1356
-11%
1254
-18%
995
-35%
1032
-32%
Colorchecker DeltaE2000 *
4.59
3.43
25%
5.17
-13%
4.6
-0%
3.61
21%
Colorchecker DeltaE2000 max. *
9.81
5.55
43%
7.68
22%
9.1
7%
7.92
19%
Colorchecker DeltaE2000 calibrated *
3.26
Greyscale DeltaE2000 *
5.2
3.08
41%
5.69
-9%
6.1
-17%
3.77
27%
Gamma
2.41 91%
3.03 73%
2.42 91%
2.07 106%
2.43 91%
CCT
7712 84%
7014 93%
7999 81%
7104 91%
6760 96%
Color Space (Percent of AdobeRGB 1998)
74
64
-14%
71
-4%
59
-20%
Color Space (Percent of sRGB)
100
99
-1%
100
0%
91
-9%
Total Average (Program / Settings)
5% / 9%
14% / 4%
6% / -8%
3% / 0%

* ... smaller is better

Color space deviation: 100% sRGB
Color space deviation: 100% sRGB
Color space deviation: 74% AdobeRGB
Color space deviation: 74% AdobeRGB

Overall, the screen does a good job despite its small size and offers great sharpness, good contrasts and rich colors, although the color deviation is slightly too high before calibration.

Nonetheless, the panel also offers good color-space coverage. sRGB is covered completely and we measured 74% coverage of AdobeRGB. Again, the C930 beats last year's Surface Pro.

Grayscales
Grayscales
Colors
Colors
Saturation
Saturation
Grayscales after calibration
Grayscales after calibration
Colors after calibration
Colors after calibration
Saturation after calibration
Saturation after calibration
Outside on overcast day
Outside on overcast day

Unlike its predecessor, the current model does not use PWM to regulate screen brightness. The response rates of the display are not brilliant but sufficient for the intended purposes.

The good black value and high contrast enable the use of the device outdoors. However, do expect some reflections due to the reflective display, which the manufacturer has chosen in order to offer stronger colors. It should still be possible to read screen content on cloudy days and when looking at the screen from a straight angle.

Display Response Times

Display response times show how fast the screen is able to change from one color to the next. Slow response times can lead to afterimages and can cause moving objects to appear blurry (ghosting). Gamers of fast-paced 3D titles should pay special attention to fast response times.
       Response Time Black to White
27 ms ... rise ↗ and fall ↘ combined↗ 13 ms rise
↘ 14 ms fall
The screen shows relatively slow response rates in our tests and may be too slow for gamers.
In comparison, all tested devices range from 0.8 (minimum) to 240 (maximum) ms. » 53 % of all devices are better.
This means that the measured response time is similar to the average of all tested devices (25.7 ms).
       Response Time 50% Grey to 80% Grey
43 ms ... rise ↗ and fall ↘ combined↗ 23 ms rise
↘ 20 ms fall
The screen shows slow response rates in our tests and will be unsatisfactory for gamers.
In comparison, all tested devices range from 0.9 (minimum) to 636 (maximum) ms. » 59 % of all devices are better.
This means that the measured response time is similar to the average of all tested devices (41 ms).

Screen Flickering / PWM (Pulse-Width Modulation)

To dim the screen, some notebooks will simply cycle the backlight on and off in rapid succession - a method called Pulse Width Modulation (PWM) . This cycling frequency should ideally be undetectable to the human eye. If said frequency is too low, users with sensitive eyes may experience strain or headaches or even notice the flickering altogether.
Screen flickering / PWM not detected

In comparison: 52 % of all tested devices do not use PWM to dim the display. If PWM was detected, an average of 9152 (minimum: 43 - maximum: 142900) Hz was measured.

Typically for IPS screens, the viewing-angle stability is good. Particularly when looking at the screen from the sides, you should hardly notice any difference. There will be some color and brightness deviations when looking at the screen from above or below, but everything is still very easy to read.

Performance - Lenovo Convertible fulfills expectations

LatencyMon: No latencies
LatencyMon: No latencies

At the time of writing, there is only one configuration of the C930 available in the US. This is equipped with an Intel Core i5-7Y54 processor and a 128-GB SSD. The German test unit we are looking at today is equipped with the Intel Core i5-7Y54 but has a 256-GB SSD storage device and also supports LTE. None of the models have a dedicated graphics card and use the integrated Intel HD Graphics 615 instead.

This configuration positions the passively cooled Yoga Book in the upper range of tablet hardware. Compared to its predecessor, which was equipped with an Intel Atom CPU, Intel HD Graphics 400 and eMMC storage, its performance should still have improved significantly. Nonetheless, we cannot expect any miracles from the C930 in terms of performance. This test unit is not made for gaming, video-editing or similarly demanding tasks. It is suited to office applications, browsing the web and simple graphics.

We did not measure any latencies despite the not-so-powerful hardware, at least according to LatencyMon.

Processor

The processor has been given an update compared to its predecessor. Instead of the Intel Atom, we are now offered an Intel Core i5-7Y54. This is an energy-efficient dual-core CPU with Hyper-Threading, an internal GPU, the Intel HD Graphics 615, and clock rates from 1.2 to 3.2 GHz. The dual-core turbo should be 2.8 GHz. The processor is designed for tablets and passively cooled notebooks; low consumption rates and low heat production are favored over high performance. Therefore, we must not expect too much from the new Yoga Book.

The 30-minute Cinebench R15 loop illustrates the Yoga Book's performance nicely: At over 230 points in our Multi test, it reaches average results at first but, like so many others, cannot keep up the good work in the subsequent rounds. Due to increased temperatures, the CPU is throttled slightly and eventually settles down to around 200 points. The competition has a similar curve progression and the Surface also settles down to around 200 points. The Matebook manages to remain slightly more stable. 

0102030405060708090100110120130140150160170180190200210220230240250260270Tooltip
Lenovo Yoga Book C930 YB-J912F Intel Core i5-7Y54, Intel Core i5-7Y54: Ø199 (173.03-236.42)
Microsoft Surface Pro (2017) m3 Intel Core m3-7Y30, Intel Core m3-7Y30: Ø209 (160.17-256.05)
Huawei Matebook E Intel Core i5-7Y54, Intel Core i5-7Y54: Ø250 (246.95-261.8)
Lenovo ThinkPad X1 Tablet Gen 2 Intel Core i5-7Y54, Intel Core i5-7Y54: Ø209 (204.92-240.58)

The Yoga Book offers the same performance when running on battery. Again, the convertible reached 234 points in the Multi CPU test.

Cinebench R15
Cinebench R15
Cinebench R11.5
Cinebench R11.5
Cinebench R10
Cinebench R10

The Yoga Book does a good job in comparison to its competitors, but the upgrade was definitely necessary. Our test unit can beat its predecessor by 75% (Multi CPU) and 222% (Single CPU). The Surface and Matebook are about 10% faster, at least in the Multi CPU test. The results are very similar in the Cinebench R11.5 and Cinebench R10. Again, the Microsoft and Huawei devices are faster by about 10%. However, the Yoga Book takes the lead in the single test. Overall, the C930 can easily keep up with the other devices and offers the expected performance.

Cinebench R15
CPU Single 64Bit
Huawei Matebook E
Intel Core i5-7Y54
124 Points ∼100% +7%
Lenovo Yoga Book C930 YB-J912F
Intel Core i5-7Y54
116 Points ∼94%
Lenovo ThinkPad X1 Tablet Gen 2
Intel Core i5-7Y54
115 Points ∼93% -1%
Average Intel Core i5-7Y54
  (111 - 124, n=7)
115 Points ∼93% -1%
Microsoft Surface Pro (2017) m3
Intel Core m3-7Y30
108 Points ∼87% -7%
Average of class Convertible
  (19 - 177, n=279)
102 Points ∼82% -12%
Lenovo Yoga Book 2016 Windows 64GB LTE
Intel Atom x5-Z8550
36 Points ∼29% -69%
CPU Multi 64Bit
Average of class Convertible
  (33 - 761, n=286)
283 Points ∼100% +21%
Microsoft Surface Pro (2017) m3
Intel Core m3-7Y30
258 Points ∼91% +10%
Huawei Matebook E
Intel Core i5-7Y54
254 Points ∼90% +9%
Lenovo ThinkPad X1 Tablet Gen 2
Intel Core i5-7Y54
234 Points ∼83% 0%
Lenovo Yoga Book C930 YB-J912F
Intel Core i5-7Y54
234 Points ∼83%
Average Intel Core i5-7Y54
  (205 - 257, n=7)
230 Points ∼81% -2%
Lenovo Yoga Book 2016 Windows 64GB LTE
Intel Atom x5-Z8550
134 Points ∼47% -43%
Cinebench R11.5
CPU Single 64Bit
Lenovo Yoga Book C930 YB-J912F
Intel Core i5-7Y54
1.41 Points ∼100%
Lenovo ThinkPad X1 Tablet Gen 2
Intel Core i5-7Y54
1.32 Points ∼94% -6%
Average Intel Core i5-7Y54
  (1.27 - 1.41, n=4)
1.318 Points ∼93% -7%
Microsoft Surface Pro (2017) m3
Intel Core m3-7Y30
1.24 Points ∼88% -12%
Average of class Convertible
  (0.24 - 2.01, n=214)
1.107 Points ∼79% -21%
CPU Multi 64Bit
Microsoft Surface Pro (2017) m3
Intel Core m3-7Y30
2.85 Points ∼100% +13%
Average of class Convertible
  (0.45 - 8.56, n=223)
2.76 Points ∼97% +9%
Lenovo ThinkPad X1 Tablet Gen 2
Intel Core i5-7Y54
2.57 Points ∼90% +2%
Lenovo Yoga Book C930 YB-J912F
Intel Core i5-7Y54
2.53 Points ∼89%
Average Intel Core i5-7Y54
  (2.27 - 2.57, n=5)
2.42 Points ∼85% -4%
Cinebench R10
Rendering Single CPUs 64Bit
Lenovo Yoga Book C930 YB-J912F
Intel Core i5-7Y54
6248 Points ∼100%
Average Intel Core i5-7Y54
  (5545 - 6248, n=3)
5813 Points ∼93% -7%
Microsoft Surface Pro (2017) m3
Intel Core m3-7Y30
5253 Points ∼84% -16%
Average of class Convertible
  (919 - 8397, n=118)
4493 Points ∼72% -28%
Rendering Multiple CPUs 64Bit
Microsoft Surface Pro (2017) m3
Intel Core m3-7Y30
11264 Points ∼100% +7%
Lenovo Yoga Book C930 YB-J912F
Intel Core i5-7Y54
10501 Points ∼93%
Average Intel Core i5-7Y54
  (8756 - 10501, n=3)
9646 Points ∼86% -8%
Average of class Convertible
  (1689 - 31667, n=117)
9522 Points ∼85% -9%
Cinebench R10 Shading 64Bit
6211 Points
Cinebench R10 Rendering Multiple CPUs 64Bit
10501 Points
Cinebench R10 Rendering Single CPUs 64Bit
6248 Points
Cinebench R11.5 CPU Multi 64Bit
2.53 Points
Cinebench R11.5 OpenGL 64Bit
26.75 fps
Cinebench R11.5 CPU Single 64Bit
1.41 Points
Cinebench R15 CPU Single 64Bit
116 Points
Cinebench R15 Ref. Match 64Bit
97.8 %
Cinebench R15 OpenGL 64Bit
34.97 fps
Cinebench R15 CPU Multi 64Bit
234 Points
Help

System Performance

The new Lenovo Yoga Book can also easily beat its predecessor in terms of system performance. However, it cannot quite keep up with the average system performance for convertibles. It is 3 - 6 points behind the expected performance for this CPU in all PCMark 10 tests. Depending on the test, it performs 10 - 50% below the average performance for convertibles. The Surface Pro always lies ahead by 5 - 30 points. The ThinkPad, also from Lenovo, has an advantage of 30 - 40% in PCMark 8 despite being equipped with the same processor. However, this device also has twice the RAM size and a faster SSD. The 4 GB of RAM in our test unit is almost the bottom limit of what appears appropriate for decent performance. Even some smartphones have larger working memories nowadays.

PCMark 10
PCMark 10
PCMark 8 Home
PCMark 8 Home
PCMark 8 Work
PCMark 8 Work
PCMark 10
Digital Content Creation
Average of class Convertible
  (605 - 4342, n=77)
2393 Points ∼100% +56%
Microsoft Surface Pro (2017) m3
HD Graphics 615, 7Y30, Samsung PM971 KUS020203M
1837 Points ∼77% +19%
Average Intel Core i5-7Y54, Intel HD Graphics 615
  (1538 - 1718, n=2)
1628 Points ∼68% +6%
Lenovo Yoga Book C930 YB-J912F
HD Graphics 615, 7Y54, Toshiba KBG30ZMT256G
1538 Points ∼64%
Productivity
Average of class Convertible
  (1121 - 7045, n=79)
5034 Points ∼100% +27%
Average Intel Core i5-7Y54, Intel HD Graphics 615
  (3969 - 4176, n=2)
4073 Points ∼81% +3%
Microsoft Surface Pro (2017) m3
HD Graphics 615, 7Y30, Samsung PM971 KUS020203M
4051 Points ∼80% +2%
Lenovo Yoga Book C930 YB-J912F
HD Graphics 615, 7Y54, Toshiba KBG30ZMT256G
3969 Points ∼79%
Essentials
Average of class Convertible
  (2489 - 9291, n=79)
6697 Points ∼100% +11%
Average Intel Core i5-7Y54, Intel HD Graphics 615
  (6033 - 6320, n=2)
6177 Points ∼92% +2%
Lenovo Yoga Book C930 YB-J912F
HD Graphics 615, 7Y54, Toshiba KBG30ZMT256G
6033 Points ∼90%
Microsoft Surface Pro (2017) m3
HD Graphics 615, 7Y30, Samsung PM971 KUS020203M
5762 Points ∼86% -4%
Score
Average of class Convertible
  (872 - 4347, n=80)
3041 Points ∼100% +28%
Microsoft Surface Pro (2017) m3
HD Graphics 615, 7Y30, Samsung PM971 KUS020203M
2509 Points ∼83% +5%
Average Intel Core i5-7Y54, Intel HD Graphics 615
  (2385 - 2556, n=2)
2471 Points ∼81% +4%
Lenovo Yoga Book C930 YB-J912F
HD Graphics 615, 7Y54, Toshiba KBG30ZMT256G
2385 Points ∼78%
PCMark 8
Work Score Accelerated v2
Lenovo ThinkPad X1 Tablet Gen 2
HD Graphics 615, 7Y54, Samsung PM961 MZVLW256HEHP
4288 Points ∼100% +32%
Average Intel Core i5-7Y54, Intel HD Graphics 615
  (3244 - 4288, n=3)
3869 Points ∼90% +19%
Average of class Convertible
  (1007 - 5281, n=209)
3645 Points ∼85% +12%
Microsoft Surface Pro (2017) m3
HD Graphics 615, 7Y30, Samsung PM971 KUS020203M
3586 Points ∼84% +11%
Lenovo Yoga Book C930 YB-J912F
HD Graphics 615, 7Y54, Toshiba KBG30ZMT256G
3244 Points ∼76%
Lenovo Yoga Book 2016 Windows 64GB LTE
HD Graphics 400 (Braswell), Z8550, 64 GB eMMC Flash
1247 Points ∼29% -62%
Home Score Accelerated v2
Lenovo ThinkPad X1 Tablet Gen 2
HD Graphics 615, 7Y54, Samsung PM961 MZVLW256HEHP
3092 Points ∼100% +39%
Huawei Matebook E
HD Graphics 615, 7Y54, SanDisk SD8SN8U256G1027
2979 Points ∼96% +33%
Microsoft Surface Pro (2017) m3
HD Graphics 615, 7Y30, Samsung PM971 KUS020203M
2896 Points ∼94% +30%
Average Intel Core i5-7Y54, Intel HD Graphics 615
  (2232 - 3092, n=7)
2823 Points ∼91% +26%
Average of class Convertible
  (741 - 4741, n=255)
2741 Points ∼89% +23%
Lenovo Yoga Book C930 YB-J912F
HD Graphics 615, 7Y54, Toshiba KBG30ZMT256G
2232 Points ∼72%
Lenovo Yoga Book 2016 Windows 64GB LTE
HD Graphics 400 (Braswell), Z8550, 64 GB eMMC Flash
1296 Points ∼42% -42%
PCMark 8 Home Score Accelerated v2
2232 points
PCMark 8 Work Score Accelerated v2
3244 points
Help

Storage Device

The 256-GB SSD from Toshiba does a good job and cannot be blamed for the mediocre system performance results. Only the SSD in the ThinkPad is significantly better. The Surface Pro (2017)'s storage device is 10% slower than that of the Yoga Book and the SSD in the Matebook is actually positioned 30% below our test unit's. The eMMC storage device in our predecessor is 90% slower. Overall, the C930 has quite good results. You can find out more about the SSD in our SSD/HDD benchmark list.

AS SSD
AS SSD
AS SSD copy benchmark
AS SSD copy benchmark
CrystalDiskMark 5
CrystalDiskMark 5
CrystalDiskMark 3
CrystalDiskMark 3
Lenovo Yoga Book C930 YB-J912F
Toshiba KBG30ZMT256G
Microsoft Surface Pro (2017) m3
Samsung PM971 KUS020203M
Huawei Matebook E
SanDisk SD8SN8U256G1027
Lenovo ThinkPad X1 Tablet Gen 2
Samsung PM961 MZVLW256HEHP
Lenovo Yoga Book 2016 Windows 64GB LTE
64 GB eMMC Flash
Average Toshiba KBG30ZMT256G
 
CrystalDiskMark 3.0
-19%
-24%
36%
-88%
0%
Write 4k QD32
165.6
172
4%
184.4
11%
259
56%
13.79
-92%
166
0%
Read 4k QD32
270.9
301.8
11%
381.8
41%
247.9
-8%
33.6
-88%
271
0%
Write 4k
90.84
98.76
9%
65.3
-28%
120
32%
11.56
-87%
90.8
0%
Read 4k
44.39
40.11
-10%
32.46
-27%
52.34
18%
13.34
-70%
44.4
0%
Write 512
665.2
241
-64%
294.7
-56%
869
31%
26.58
-96%
665
0%
Read 512
721
261.1
-64%
341.9
-53%
697.5
-3%
102.6
-86%
721
0%
Write Seq
759.2
669.9
-12%
461
-39%
1259
66%
34.39
-95%
759
0%
Read Seq
879.9
690.5
-22%
506.1
-42%
1739
98%
120.5
-86%
880
0%
AS SSD
-5%
-39%
106%
-93%
0%
Copy Game MB/s
254.54
140.69
-45%
302.75
19%
255
0%
Copy Program MB/s
94.34
83.82
-11%
320.8
240%
94.3
0%
Copy ISO MB/s
448.1
173.16
-61%
693.57
55%
448
0%
Score Total
1526
1847
21%
890
-42%
4470
193%
1526
0%
Score Write
403
284
-30%
230
-43%
812
101%
403
0%
Score Read
749
1053
41%
439
-41%
2465
229%
749
0%
Access Time Write *
0.176
0.04
77%
0.075
57%
0.028
84%
0.176
-0%
Access Time Read *
0.057
0.074
-30%
0.107
-88%
0.054
5%
0.057
-0%
4K-64 Write
231.66
144.25
-38%
149.56
-35%
597.8
158%
232
0%
4K-64 Read
581.83
891.36
53%
359.7
-38%
2207.86
279%
582
0%
4K Write
91.62
88.56
-3%
60.47
-34%
125.81
37%
91.6
0%
4K Read
43.38
38.82
-11%
30.43
-30%
44.11
2%
43.4
0%
Seq Write
797.05
514.35
-35%
202.05
-75%
886.85
11%
28.76
-96%
797
0%
Seq Read
1240.52
1225.84
-1%
489.83
-61%
2130.09
72%
128.38
-90%
1241
0%
Total Average (Program / Settings)
-12% / -10%
-32% / -33%
71% / 81%
-91% / -89%
0% / 0%

* ... smaller is better

Toshiba KBG30ZMT256G
Sequential Read: 879.9 MB/s
Sequential Write: 759.2 MB/s
512K Read: 721 MB/s
512K Write: 665.2 MB/s
4K Read: 44.39 MB/s
4K Write: 90.84 MB/s
4K QD32 Read: 270.9 MB/s
4K QD32 Write: 165.6 MB/s

Graphics Performance

The Lenovo Yoga Book only has an integrated graphics card. The Intel HD Graphics 615 is more than two years old and uses the system RAM as it does not have its own dedicated VRAM. The convertible is not intended for gaming but can display 4K/H.265 videos smoothly.

3DMark 11
3DMark 11
3DMark Fire Strike
3DMark Fire Strike
3DMark Cloud Gate
3DMark Cloud Gate

The Yoga Book did a good job in our 3DMark tests. It was a whole 200% faster than its predecessor in 3DMark 11 and manages first place in our comparison table. However, only about 3% lies between the C930 and its rivals. The largest differences appear in the Fire Strike test. The Lenovo convertible is at the top while the Surface Pro and ThinkPad are behind by about 10%. Again, the C930 performs just as we would have expected from its hardware configuration.        

Luckily the performance of the Yoga Book does not drop in battery mode. That is very good news.

3DMark 11 - 1280x720 Performance GPU
Lenovo Yoga Book C930 YB-J912F
Intel HD Graphics 615, Intel Core i5-7Y54
1267 Points ∼100%
Huawei Matebook E
Intel HD Graphics 615, Intel Core i5-7Y54
1256 Points ∼99% -1%
Microsoft Surface Pro (2017) m3
Intel HD Graphics 615, Intel Core m3-7Y30
1251 Points ∼99% -1%
Average Intel HD Graphics 615
  (1032 - 1384, n=14)
1233 Points ∼97% -3%
Average of class Convertible
  (173 - 7483, n=307)
1201 Points ∼95% -5%
Lenovo ThinkPad X1 Tablet Gen 2
Intel HD Graphics 615, Intel Core i5-7Y54
1161 Points ∼92% -8%
Lenovo Yoga Book 2016 Windows 64GB LTE
Intel HD Graphics 400 (Braswell), Intel Atom x5-Z8550
418 Points ∼33% -67%
3DMark
1920x1080 Fire Strike Graphics
Average of class Convertible
  (132 - 5965, n=218)
973 Points ∼100% +18%
Average Intel HD Graphics 615
  (647 - 965, n=11)
830 Points ∼85% 0%
Lenovo Yoga Book C930 YB-J912F
Intel HD Graphics 615, Intel Core i5-7Y54
826 Points ∼85%
Microsoft Surface Pro (2017) m3
Intel HD Graphics 615, Intel Core m3-7Y30
748 Points ∼77% -9%
Lenovo ThinkPad X1 Tablet Gen 2
Intel HD Graphics 615, Intel Core i5-7Y54
728 Points ∼75% -12%
1280x720 Cloud Gate Standard Graphics
Average Intel HD Graphics 615
  (5478 - 7839, n=13)
6502 Points ∼100% +1%
Average of class Convertible
  (1023 - 37388, n=268)
6436 Points ∼99% 0%
Lenovo Yoga Book C930 YB-J912F
Intel HD Graphics 615, Intel Core i5-7Y54
6430 Points ∼99%
Lenovo ThinkPad X1 Tablet Gen 2
Intel HD Graphics 615, Intel Core i5-7Y54
6164 Points ∼95% -4%
Microsoft Surface Pro (2017) m3
Intel HD Graphics 615, Intel Core m3-7Y30
6096 Points ∼94% -5%
Lenovo Yoga Book 2016 Windows 64GB LTE
Intel HD Graphics 400 (Braswell), Intel Atom x5-Z8550
2455 Points ∼38% -62%
3DMark 11 Performance
1367 points
3DMark Cloud Gate Standard Score
4893 points
3DMark Fire Strike Score
747 points
Help

Gaming Performance

Despite the relatively new CPU and better (internal) graphics card, the Yoga Book is quite unsuitable for gaming. Even undemanding games such as Rocket League can hardly be displayed smoothly. You may be able to play some older games in low resolution and low details. Skyrim from 2011, for example, can be played at around 35 fps. Apart from that, the gaming possibilities are limited to very simple titles such as Candy Crush (preinstalled) or Farmville 2 from the Windows Store.

low med. high ultra
The Elder Scrolls V: Skyrim (2011) 35.1187.9fps
Tomb Raider (2013) 61.428.918.4fps
Rocket League (2017) 26.4fps

Emissions - calm Yoga Laptop

System Noise

As the convertible is passively cooled and does not have a cooling fan, there is no system noise. We did not hear any bothersome electronic noise coming from the device either.

Temperature

The surface temperature remains reasonably low. Although the C930 heats up a little more than its predecessor did while idling and under load, these small differences in temperature are actually very good considering the great performance increase. As the convertible will hardly have to deal with heavy loads, it should not heat up very often. Under normal load, you can expect surface temperatures around 28 °C. Only in extreme situations might the temperature rise to around 44 °C, particularly in the right area near the screen. The wrist rest remains comfortably cool at all times.

Idle top
Idle top
Idle bottom
Idle bottom
Load top
Load top
Load bottom
Load bottom

The Surface Pro (2017) and the ThinkPad both heat up more while idling. Under load, the Surface is slightly cooler while the ThinkPad reaches higher temperatures. The Huawei Matebook and the predecessor both remain cooler by about 10%.

Lenovo Yoga Book C930 YB-J912F
HD Graphics 615, 7Y54, Toshiba KBG30ZMT256G
Microsoft Surface Pro (2017) m3
HD Graphics 615, 7Y30, Samsung PM971 KUS020203M
Huawei Matebook E
HD Graphics 615, 7Y54, SanDisk SD8SN8U256G1027
Lenovo ThinkPad X1 Tablet Gen 2
HD Graphics 615, 7Y54, Samsung PM961 MZVLW256HEHP
Lenovo Yoga Book 2016 Windows 64GB LTE
HD Graphics 400 (Braswell), Z8550, 64 GB eMMC Flash
Heat
-9%
11%
-10%
10%
Maximum Upper Side *
42
40.5
4%
36.3
14%
47.2
-12%
34
19%
Maximum Bottom *
43.8
40.6
7%
37.9
13%
49.8
-14%
40.2
8%
Idle Upper Side *
27.7
37.8
-36%
26.2
5%
30.8
-11%
25.7
7%
Idle Bottom *
28.7
32
-11%
25.6
11%
29.2
-2%
27.1
6%

* ... smaller is better

The convertible is not intended for high-stress situations. Nonetheless, we decided to run our stress test to get an idea of the device's behavior in terms of temperature and clock rate under load. As soon as Prime95 and FurMark are turned on, the processor falls below its base clock rate of 1.2 GHz. At first it clocks at around 1 GHz but then drops further. After 10 - 15 minutes, the CPU clock rate settles down at around 500 MHz. There would actually still be room for more as the core temperatures lie around 50 °C throughout the test. The CPU suffers from strong throttling, which makes it basically impossible to execute complex applications. But this should not be expected from a tablet notebook anyway. The extremely thin case and passive cooling mean that Lenovo has to limit its performance quite quickly as it is difficult to transfer heat out of the small device. 

Beginning of stress test: around 1 GHz
Beginning of stress test: around 1 GHz
Stress test after 45 minutes: around 500 MHz
Stress test after 45 minutes: around 500 MHz

By the way: The performance is 35% lower when running 3DMark 11 right after the stress test.

3DMark 11 normal
3DMark 11 normal
3DMark 11 after stress test
3DMark 11 after stress test
Max. Load
 37.1 °C
99 F
42 °C
108 F
41 °C
106 F
 
 33.6 °C
92 F
36.8 °C
98 F
36.9 °C
98 F
 
 31.5 °C
89 F
33.3 °C
92 F
33.4 °C
92 F
 
Maximum: 42 °C = 108 F
Average: 36.2 °C = 97 F
43.1 °C
110 F
43.8 °C
111 F
39.1 °C
102 F
39.3 °C
103 F
38.5 °C
101 F
36.5 °C
98 F
34.9 °C
95 F
35.4 °C
96 F
34 °C
93 F
Maximum: 43.8 °C = 111 F
Average: 38.3 °C = 101 F
Power Supply (max.)  41.7 °C = 107 F | Room Temperature 23.2 °C = 74 F | FIRT 550-Pocket
(±) The average temperature for the upper side under maximal load is 36.2 °C / 97 F, compared to the average of 30.4 °C / 87 F for the devices in the class Convertible.
(±) The maximum temperature on the upper side is 42 °C / 108 F, compared to the average of 35.4 °C / 96 F, ranging from 21.8 to 55.7 °C for the class Convertible.
(±) The bottom heats up to a maximum of 43.8 °C / 111 F, compared to the average of 36.5 °C / 98 F
(+) In idle usage, the average temperature for the upper side is 26.3 °C / 79 F, compared to the device average of 30.4 °C / 87 F.
(+) The palmrests and touchpad are reaching skin temperature as a maximum (33.4 °C / 92.1 F) and are therefore not hot.
(-) The average temperature of the palmrest area of similar devices was 29.1 °C / 84.4 F (-4.3 °C / -7.7 F).

Speakers

Nobody can expect excellent sound with strong, deep bass tones from a tablet convertible. At least the stereo speakers produce a relatively balanced sound, although it is a little on the quiet side. We have heard a lot worse. Nonetheless, we would recommend using headphones when watching videos. Unfortunately, the Yoga Book C930 does not have a headphone jack. Users will have to purchase a USB-C-to-audio-jack adapter, as this is not included either. This also takes up one of the two available USB ports.

dB(A) 0102030405060708090Deep BassMiddle BassHigh BassLower RangeMidsHigher MidsLower HighsMid HighsUpper HighsSuper Highs2044.937.244.92539.43639.43135.831.235.84037.228.537.25038.532.238.56340.428.740.4803928.63910040.627.540.612540.325.140.316043.825.543.820046.623.646.625049.32349.331557.822.157.840059.72159.750061.120.261.163061.12061.180063.318.763.3100063.117.963.1125064.91864.9160063.717.363.7200067.317.367.3250065.817.365.831506217.262400059.41759.45000571757630049.417.149.4800051.917.151.91000054.517.354.51250049.617.349.61600043.517.543.5SPL74.630.274.6N31.41.231.4median 57.8median 17.9median 57.8Delta72.7735.335.132.931.831.83236.535.132.428.93328.936.328.848.32761.52752.924.860.92462.822.763.32269.521.267.82174.82075.919.472.718.97117.770.117.86917.671.817.668.117.671.417.673.717.670.417.571.617.671.617.669.617.459.717.583.630.662.51.5median 69.6median 17.84.62.4hearing rangehide median Pink NoiseLenovo Yoga Book C930 YB-J912FApple MacBook 12 (Early 2016) 1.1 GHz
Frequency diagram (checkboxes can be checked and unchecked to compare devices)
Lenovo Yoga Book C930 YB-J912F audio analysis

(-) | not very loud speakers (67.29 dB)
Bass 100 - 315 Hz
(±) | reduced bass - on average 11.4% lower than median
(±) | linearity of bass is average (8.1% delta to prev. frequency)
Mids 400 - 2000 Hz
(±) | higher mids - on average 5.2% higher than median
(+) | mids are linear (3.8% delta to prev. frequency)
Highs 2 - 16 kHz
(+) | balanced highs - only 4.6% away from median
(±) | linearity of highs is average (8.3% delta to prev. frequency)
Overall 100 - 16.000 Hz
(±) | linearity of overall sound is average (18% difference to median)
Compared to same class
» 28% of all tested devices in this class were better, 8% similar, 64% worse
» The best had a delta of 11%, average was 22%, worst was 53%
Compared to all devices tested
» 30% of all tested devices were better, 6% similar, 63% worse
» The best had a delta of 3%, average was 21%, worst was 53%

Apple MacBook 12 (Early 2016) 1.1 GHz audio analysis

(+) | speakers can play relatively loud (83.6 dB)
Bass 100 - 315 Hz
(±) | reduced bass - on average 11.3% lower than median
(±) | linearity of bass is average (14.2% delta to prev. frequency)
Mids 400 - 2000 Hz
(+) | balanced mids - only 2.4% away from median
(+) | mids are linear (5.5% delta to prev. frequency)
Highs 2 - 16 kHz
(+) | balanced highs - only 2% away from median
(+) | highs are linear (4.5% delta to prev. frequency)
Overall 100 - 16.000 Hz
(+) | overall sound is linear (9.3% difference to median)
Compared to same class
» 2% of all tested devices in this class were better, 2% similar, 97% worse
» The best had a delta of 8%, average was 19%, worst was 50%
Compared to all devices tested
» 2% of all tested devices were better, 1% similar, 98% worse
» The best had a delta of 3%, average was 21%, worst was 53%

Energy Management - weak Lenovo

Power Consumption

Power supply, max. 27 watts
Power supply, max. 27 watts

Considering the significantly increased performance, we are not surprised that the Yoga Book consumes noticeably more power than its predecessor from 2016. The latter consumed about 44% less energy. Still, the power consumption of our test unit is not that high and can be compared to those of the Surface Pro and Matebook. The ThinkPad is about 9% more efficient. 

The maximum consumption we measured under heavy load was 30.5 watts. The power supply only offers 27 watts (3A, 9V) which means that the convertible would actually consume additional power from the battery in such a case. However, this represents an extreme scenario that should not occur during everyday use.

Power Consumption
Off / Standbydarklight 0.35 / 0.75 Watt
Idledarkmidlight 5.3 / 6.9 / 7.4 Watt
Load midlight 19.7 / 30.5 Watt
 color bar
Key: min: dark, med: mid, max: light        Metrahit Energy
Lenovo Yoga Book C930 YB-J912F
7Y54, HD Graphics 615, Toshiba KBG30ZMT256G, IPS, 2560x1660, 10.8
Lenovo Yoga Book 2016 Windows 64GB LTE
Z8550, HD Graphics 400 (Braswell), 64 GB eMMC Flash, IPS , 1920x1080, 10.1
Microsoft Surface Pro (2017) m3
7Y30, HD Graphics 615, Samsung PM971 KUS020203M, IPS, 2736x1826, 12.3
Huawei Matebook E
7Y54, HD Graphics 615, SanDisk SD8SN8U256G1027, IPS, 2160x1440, 12
Lenovo ThinkPad X1 Tablet Gen 2
7Y54, HD Graphics 615, Samsung PM961 MZVLW256HEHP, IPS, 2160x1440, 12
Average Intel HD Graphics 615
 
Average of class Convertible
 
Power Consumption
44%
-2%
1%
9%
7%
-13%
Idle Minimum *
5.3
2
62%
3.1
42%
3.9
26%
5
6%
4.12 (2.8 - 8.2, n=16)
22%
4.73 (1.4 - 23, n=352)
11%
Idle Average *
6.9
4.6
33%
8.8
-28%
8.8
-28%
6.3
9%
7.02 (5.5 - 10.8, n=16)
-2%
7.9 (3.8 - 32.3, n=352)
-14%
Idle Maximum *
7.4
5.7
23%
9.8
-32%
8.9
-20%
7.8
-5%
7.89 (7.4 - 12.7, n=16)
-7%
9.39 (4.1 - 61, n=352)
-27%
Load Average *
19.7
11.5
42%
22.7
-15%
20
-2%
19.5
1%
20 (18.4 - 25.1, n=16)
-2%
26.2 (1.4 - 94, n=350)
-33%
Load Maximum *
30.5
11.5
62%
23.6
23%
21.8
29%
19.6
36%
23.8 (20 - 36.1, n=16)
22%
30.7 (7.9 - 117, n=351)
-1%

* ... smaller is better

Battery Runtimes

We measure the maximum battery runtime with Battery Eater. The display brightness was set to minimum and all communication modules were turned off for this test. The Readers Test simulates low load. In this scenario, the Lenovo managed about 11 hours and 30 minutes.

Our more practical test looks at the battery runtime while browsing the web via Wi-Fi. The brightness is slightly reduced, Wi-Fi is turned on and we use a script to load different webpages every minute, occasionally playing YouTube videos. Our test unit managed a battery runtime of 6 hours and 20 minutes here.

In our video test, we turn on flight mode and again reduce the brightness slightly. The video is played in a loop with the sound turned off. The Yoga Book turned off after about 3 hours in this test. 

In order to really tax the battery, we turned on all power guzzlers such as Wi-Fi and Bluetooth, maximized the brightness and simulated high loads with Battery Eater Classic. The Yoga Book's minimum runtime lay at around 1.5 hours.

Compared to our competitors, the battery runtimes are average at best. The battery requires over 3 hours to recharge fully.

Battery Runtime
Idle (without WLAN, min brightness)
11h 30min
NBC WiFi Websurfing Battery Test 1.3
6h 20min
Big Buck Bunny H.264 1080p
6h 35min
Load (maximum brightness)
2h 33min
Lenovo Yoga Book C930 YB-J912F
7Y54, HD Graphics 615, 36 Wh
Microsoft Surface Pro (2017) m3
7Y30, HD Graphics 615, 45 Wh
Huawei Matebook E
7Y54, HD Graphics 615, 33.7 Wh
Lenovo ThinkPad X1 Tablet Gen 2
7Y54, HD Graphics 615, 37 Wh
Lenovo Yoga Book 2016 Windows 64GB LTE
Z8550, HD Graphics 400 (Braswell), 32 Wh
Average of class Convertible
 
Battery Runtime
53%
7%
0%
49%
10%
Reader / Idle
690
933
35%
662
-4%
1153
67%
764 (117 - 1985, n=280)
11%
H.264
395
668
69%
446 (206 - 1070, n=103)
13%
WiFi v1.3
380
682
79%
405
7%
441
16%
498
31%
451 (153 - 1010, n=227)
19%
Load
153
198
29%
134
-12%
148 (49 - 677, n=269)
-3%

Verdict - versatile Windows Book

Pros

+ 3 in 1: laptop, tablet & e-reader
+ significantly more powerful than its predecessor
+ very good display
+ LTE
+ decent SSD
+ no loss in performance in battery mode
+ very small and light
+ E-Ink input options: pen, touch, keyboard
+ silent and fan-free, remains cool

Cons

- limited port selection
- no headphone jack
- battery runtime is worse than that of its predecessor
- no keyboard backlighting
- performance drops under strong load
- microSD slot must be opened with a pin
- bad camera
- touchpad is too small
The Lenovo Yoga Book C930, test unit provided by Notebooksbilliger.de
The Lenovo Yoga Book C930, test unit provided by Notebooksbilliger.de

The new Yoga Book features an E-Ink display that makes it very unique. Its biggest advantage is its versatility. It is extremely small and light and can be used for drawing on, as a notebook or tablet or as an e-reader. But of course this flexibility also requires some compromises.

For example, the keyboard is not suitable for frequent typers and does not have backlighting. The meager port selection could also be bothersome for traditional notebook users. If an e-reader is all you need, you will probably find even lighter devices.

The Lenovo Book is directed at people who would like to combine all its functions (touch, pen, e-reader, etc.) into one device. Users who are looking for a normal laptop might be happier with a different device.

Nonetheless, it is surprising to see how well Lenovo has managed to combine all these functions into such a light device. Its design and cool functions (knocking) turn the Book C930 into a real eye-catcher. As we do not have a separate category for E-Ink displays in our evaluation system, we manually added two points to the result. 

Some users might consider the price to be a further disadvantage. With a starting price of $1050, the device costs about double as much as its predecessor did. Apart from the many improvements, some functions have also disappeared. The possibility to digitalize images from paper is no longer available. The better main camera is also missing and, unfortunately, the battery runtime is significantly shorter than that of its predecessor. Instead, performance has increased dramatically and the display is better as well. Last but not least: Currently the device has no real competitors.

Lenovo Yoga Book C930 YB-J912F - 12/22/2018 v6
Christian Hintze

Chassis
82 / 98 → 83%
Keyboard
60%
Pointing Device
78%
Connectivity
41 / 80 → 51%
Weight
79 / 35-78 → 100%
Battery
88%
Display
86%
Games Performance
47 / 68 → 69%
Application Performance
67 / 87 → 77%
Temperature
90%
Noise
100%
Audio
36 / 91 → 40%
Camera
42 / 85 → 49%
Add Points
+2%
Average
64%
84%
Convertible - Weighted Average

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> Notebook / Laptop Reviews and News > Reviews > Lenovo Yoga Book C930 (i5-7Y54, LTE, E-Ink) Convertible Review
Christian Hintze, 2018-12-24 (Update: 2018-12-24)