Notebookcheck

Fujitsu Lifebook U939X Review: A business convertible with a lot of functionalities

A classic base. While the Fujitsu Lifebook U939X is clearly targeted towards business customers, it also brings many characteristics that might drive private users towards a purchase. Our review will clarify all the details.
Mike Wobker, Andrea Grüblinger (translated by Mark Riege),
Fujitsu Lifebook U939X

Before Fujitsu equips its Lifebooks with Comet Lake CPUs next month, we take another look at the models with Whiskey Lake processors. Our test unit of the Lifebook U939X business convertible is configured with an Intel Core i5-8265U, which together with 16 GB of RAM and a 512 GB SSD ensures smooth system operation.

With this hardware at a price of about 1700 Euros (~$1912; starting at $1600 in the US), the Fujitsu Lifebook U939X has to compete with the devices listed below. Below each of the sections, you can also add other notebooks from our database for comparison.

Fujitsu Lifebook U939X (LifeBook U Series)
Processor
Intel Core i5-8265U 4 x 1.6 - 3.9 GHz, Whiskey Lake-U
Graphics adapter
Memory
16384 MB 
, dual channel
Display
13.3 inch 16:9, 1920 x 1080 pixel 165 PPI, capacitive, Sharp SHP14B0, IPS, glossy: no
Mainboard
Intel Cannon Lake-U PCH-LP Premium
Storage
Samsung SSD PM981 MZVLB512HAJQ, 512 GB 
, 433 GB free
Soundcard
Intel Cannon Lake-LP - cAVS
Connections
2 USB 3.0 / 3.1 Gen1, 2 Thunderbolt, 1 HDMI, 1 Kensington Lock, Audio Connections: 3.5 mm audio combo port, Card Reader: SD, 1 SmartCard, 1 Fingerprint Reader
Networking
Intel Ethernet Connection I219-LM (10/100/1000/2500/5000MBit/s), Intel Wireless-AC 9560 (a/b/g/n = Wi-Fi 4/ac = Wi-Fi 5), Bluetooth 5, LTE Sierra Wireless EM7455 (Cat. 6), LTE
Size
height x width x depth (in mm): 17 x 309 x 215 ( = 0.67 x 12.17 x 8.46 in)
Battery
50 Wh Lithium-Polymer, Battery runtime (according to manufacturer): 15 h
Operating System
Microsoft Windows 10 Pro 64 Bit
Camera
Primary Camera: 5 MPix 4:3 (2592x1944), auto-focus
Secondary Camera: 2.1 MPix 16:9 (1920x1080)
Additional features
Speakers: 2, stereo, Keyboard: chiclet, Keyboard Light: yes, 65-Watt power supply, tablet stylus, Fujitsu Desk Update, Fujitsu WorkPlace Protect, McAfee Livesafe, 24 Months Warranty
Weight
1.027 kg ( = 36.23 oz / 2.26 pounds), Power Supply: 349 g ( = 12.31 oz / 0.77 pounds)
Price
1700 Euro
Note: The manufacturer may use components from different suppliers including display panels, drives or memory sticks with similar specifications.

 

Rating
Date
Model
Weight
Height
Size
Resolution
Best Price
85 %
07/2020
Fujitsu Lifebook U939X
i5-8265U, UHD Graphics 620
1 kg17 mm13.3"1920x1080
90 %
04/2020
HP Elite Dragonfly-8MK79EA
i5-8265U, UHD Graphics 620
1.1 kg16.1 mm13.3"1920x1080
85 %
05/2020
Asus ZenBook Flip 14 UX463FA-AI039T
i5-10210U, UHD Graphics 620
1.4 kg18 mm14"1920x1080
90 %
04/2020
Lenovo ThinkPad X1 Yoga 20SA000GUS
i7-10510U, UHD Graphics 620
1.3 kg15.5 mm14"2560x1440

Case and Equipment - Windows convertible with Thunderbolt 3

Maintenance options
Maintenance options

Fujitsu has equipped the Lifebook U939X with a magnesium case, which provides the convertible with good stability and is available in black or red color variants. The matte surface offers a good grip and a high-quality feel. In addition, the 360-degree hinge secures the display tightly in any position, which enforces the positive impression. With a weight of about one kilogram (~2.2 lb), the Windows convertible is also very light and can be used for everyday tasks without any problems. 

There are several Philips screws at the bottom of the Lifebook U939X. After removing them, users will easily be able to remove the bottom of the case. Below, they get access to the WLAN and WWAN modules, and the SSD can also be replaced. However, Fujitsu has directly integrated the working memory on-board, making a later upgrade impossible.

With its numerous connections, the Lifebook U939X will fulfill many demands. Since Fujitsu has also built in two Thunderbolt 3 ports, you can also add many more connections if you use the corresponding docking stations. Business users will also find a smart card reader, a fingerprint reader, and a TPM-2.0 module.

The equipment is completed by a full SD card reader that allows cards to be completely inserted. Using our Toshiba Exceria Pro SDXC 64 GB UHS-II reference storage card, it reaches very good speeds at 154 MB/s when copying and 183.7 MB/s when reading data.

The built-in WLAN adapter supports Wi-Fi 5 (802.11ac). In our WLAN test with the Netgear Nighthawk AX12 reference router, it achieves average speeds. However, the Lifebook U939X is unable to keep up with devices that support the current Wi-Fi 6 standard.

For video conferencing and the occasional image recordings, the Lifebook U939X offers users two cameras. There is a 2.1-MP sensor below the display, which can record images at a rather mediocre quality. In our test, we also saw some strong graininess in parts in images recorded inside rooms lit by daylight. The second camera is above the keyboard, so that it is positioned on the back in tablet mode. With its 5-MP sensor, it is able to record a recognizable image of our test chart, but details and fine structures already become blurry even at low zoom levels. The ColorChecker Passport also shows that colors are reproduced significantly brighter than they should be. 

Size Comparison

323 mm / 12.7 inch 218 mm / 8.58 inch 15.5 mm / 0.61 inch 1.3 kg2.97 lbs320 mm / 12.6 inch 206 mm / 8.11 inch 18 mm / 0.709 inch 1.4 kg3.09 lbs309 mm / 12.2 inch 215 mm / 8.46 inch 17 mm / 0.669 inch 1 kg2.26 lbs304.3 mm / 12 inch 197.5 mm / 7.78 inch 16.1 mm / 0.634 inch 1.1 kg2.51 lbs

Connectivity

Left side: power, 2x Thunderbolt 3, HDMI, 1x USB Type-A 3.1 Gen1, 3.5-mm audio port, smart card reader
Left side: power, 2x Thunderbolt 3, HDMI, 1x USB Type-A 3.1 Gen1, 3.5-mm audio port, smart card reader
Right side: stylus slot, SIM card slot, power button, SD card reader, 1x USB Type-A 3.1 Gen1, GigabitLAN, Kensington lock
Right side: stylus slot, SIM card slot, power button, SD card reader, 1x USB Type-A 3.1 Gen1, GigabitLAN, Kensington lock
SDCardreader Transfer Speed
average JPG Copy Test (av. of 3 runs)
Fujitsu Lifebook U939X
  (Toshiba Exceria Pro SDXC 64 GB UHS-II)
154 MB/s ∼100%
Average of class Convertible
  (7.5 - 197, n=157)
64.5 MB/s ∼42% -58%
Asus ZenBook Flip 14 UX463FA-AI039T
  (Toshiba Exceria Pro M501 microSDXC 64GB)
26.7 MB/s ∼17% -83%
maximum AS SSD Seq Read Test (1GB)
Fujitsu Lifebook U939X
  (Toshiba Exceria Pro SDXC 64 GB UHS-II)
183.7 MB/s ∼100%
Average of class Convertible
  (19.2 - 246, n=152)
79.9 MB/s ∼43% -57%
Asus ZenBook Flip 14 UX463FA-AI039T
  (Toshiba Exceria Pro M501 microSDXC 64GB)
27.5 MB/s ∼15% -85%
Networking
iperf3 Client (receive) TCP 1 m 4M x10
HP Elite Dragonfly-8MK79EA
Intel Wi-Fi 6 AX200
1454 (1393min - 1484max) MBit/s ∼100% +124%
Asus ZenBook Flip 14 UX463FA-AI039T
Intel Wi-Fi 6 AX201
1417 (1353min - 1440max) MBit/s ∼97% +118%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Wireless-AC 9560
1199 (600min - 1243max) MBit/s ∼82% +85%
Average Intel Wireless-AC 9560
  (312 - 1380, n=173)
687 MBit/s ∼47% +6%
Fujitsu Lifebook U939X
Intel Wireless-AC 9560
649 (586min - 678max) MBit/s ∼45%
iperf3 Client (transmit) TCP 1 m 4M x10
HP Elite Dragonfly-8MK79EA
Intel Wi-Fi 6 AX200
1411 (1311min - 1563max) MBit/s ∼100% +124%
Asus ZenBook Flip 14 UX463FA-AI039T
Intel Wi-Fi 6 AX201
1383 (1321min - 1649max) MBit/s ∼98% +120%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Wireless-AC 9560
1240 (1061min - 1422max) MBit/s ∼88% +97%
Average Intel Wireless-AC 9560
  (309 - 1338, n=172)
673 MBit/s ∼48% +7%
Fujitsu Lifebook U939X
Intel Wireless-AC 9560
630 (329min - 668max) MBit/s ∼45%
01002003004005006007008009001000110012001300140015001600Tooltip
Fujitsu Lifebook U939X Intel Core i5-8265U, Intel UHD Graphics 620; iperf3 Client (receive) TCP 1 m 4M x10; iperf 3.1.3: Ø649 (586-678)
HP Elite Dragonfly-8MK79EA Intel Core i5-8265U, Intel UHD Graphics 620; iperf3 Client (receive) TCP 1 m 4M x10; iperf 3.1.3: Ø1454 (1393-1484)
Asus ZenBook Flip 14 UX463FA-AI039T Intel Core i5-10210U, Intel UHD Graphics 620; iperf3 Client (receive) TCP 1 m 4M x10; iperf 3.1.3: Ø1417 (1353-1440)
Lenovo ThinkPad X1 Yoga 20SA000GUS Intel Core i7-10510U, Intel UHD Graphics 620; iperf3 Client (receive) TCP 1 m 4M x10; iperf 3.1.3: Ø1178 (600-1243)
Fujitsu Lifebook U939X Intel Core i5-8265U, Intel UHD Graphics 620; iperf3 Client (transmit) TCP 1 m 4M x10; iperf 3.1.3: Ø618 (329-668)
HP Elite Dragonfly-8MK79EA Intel Core i5-8265U, Intel UHD Graphics 620; iperf3 Client (transmit) TCP 1 m 4M x10; iperf 3.1.3: Ø1411 (1311-1563)
Asus ZenBook Flip 14 UX463FA-AI039T Intel Core i5-10210U, Intel UHD Graphics 620; iperf3 Client (transmit) TCP 1 m 4M x10; iperf 3.1.3: Ø1383 (1321-1649)
Lenovo ThinkPad X1 Yoga 20SA000GUS Intel Core i7-10510U, Intel UHD Graphics 620; iperf3 Client (transmit) TCP 1 m 4M x10; iperf 3.1.3: Ø1240 (1061-1422)
ColorChecker
19 ∆E
18.9 ∆E
20.4 ∆E
16 ∆E
19.7 ∆E
14.7 ∆E
15.3 ∆E
25.8 ∆E
20.4 ∆E
14.9 ∆E
12.7 ∆E
10.6 ∆E
15.9 ∆E
12.1 ∆E
22.8 ∆E
7.8 ∆E
18.6 ∆E
14.4 ∆E
1.9 ∆E
10.6 ∆E
10.6 ∆E
9.3 ∆E
5.1 ∆E
6.1 ∆E
ColorChecker Fujitsu Lifebook U939X: 14.31 ∆E min: 1.87 - max: 25.83 ∆E

Input Devices - A convincing non-reflective touchscreen

The keyboard of the Lifebook U939X offers relatively small keys that also have a fairly soft pressure point. This requires a short time of getting used to the keyboard, before longer typing tasks can also be mastered easily. While the arrow and special keys turn out a little smaller, the PgUp, PgDown, Home, End, Insert, and Delete keys are positioned as separate keys and can therefore be reached easily.

A classic touchpad with separate keys is available as the mouse replacement. It offers a slight resistance to the fingertips, slightly interfering with drag-and-drop movements. During stronger touch input, the mouse keys also clatter slightly inside their frames. However, the left and right mouse keys respond to clicks reliably and with a slight noise and noticeable pressure point. 

The highlight of the Lifebook U939X is the non-reflective touchscreen. In combination with the included input stylus it makes very accurate inputs possible. But the screen also responds very directly to touch without using the stylus.

Fujitsu Lifebook U939X - input devices
Fujitsu Lifebook U939X - input devices
Fujitsu Lifebook U939X - keyboard illumination
Fujitsu Lifebook U939X - keyboard illumination

Display - The Lifebook U939X does not use PWM

Subpixel grid
Subpixel grid

The display of the Fujitsu Lifebook U939X consists of a 13.3-inch IPS panel offering a resolution of 1920x1080 pixels. At an average of 310 cd/m², the brightness is at a comparatively high level and can also be maintained in battery operation. With a brightness distribution of 89%, the display offers the best value in our test field.

Our measurements also show that Fujitsu does not use PWM for brightness control, making the display of the Lifebook U939X also very suitable for users with sensitive eyes.

296
cd/m²
293
cd/m²
290
cd/m²
324
cd/m²
325
cd/m²
309
cd/m²
322
cd/m²
326
cd/m²
305
cd/m²
Distribution of brightness
Sharp SHP14B0
X-Rite i1Pro 2
Maximum: 326 cd/m² Average: 310 cd/m² Minimum: 26.4 cd/m²
Brightness Distribution: 89 %
Center on Battery: 324 cd/m²
Contrast: 1121:1 (Black: 0.29 cd/m²)
ΔE Color 3.2 | 0.6-29.43 Ø5.8, calibrated: 1.1
ΔE Greyscale 4.4 | 0.64-98 Ø6
96.6% sRGB (Argyll 3D) 62.9% AdobeRGB 1998 (Argyll 3D)
Gamma: 2.21
Fujitsu Lifebook U939X
Sharp SHP14B0, IPS, 1920x1080, 13.3
HP Elite Dragonfly-8MK79EA
AUO5E2D, IPS, 1920x1080, 13.3
Asus ZenBook Flip 14 UX463FA-AI039T
AU AUO323D, IPS, 1920x1080, 14
Lenovo ThinkPad X1 Yoga 20SA000GUS
AU Optronics B140QAN02.2, IPS, 2560x1440, 14
Response Times
-8%
25%
35%
Response Time Grey 50% / Grey 80% *
54.4 (26.8, 27.6)
60.8 (30.8, 30)
-12%
36 (18, 18)
34%
32 (16.4, 15.6)
41%
Response Time Black / White *
32.8 (16.4, 16.4)
33.8 (17.2, 16.6)
-3%
28 (16, 12)
15%
23.6 (12.8, 10.8)
28%
PWM Frequency
Screen
25%
-22%
1%
Brightness middle
325
411
26%
280
-14%
284.6
-12%
Brightness
310
388
25%
286
-8%
269
-13%
Brightness Distribution
89
87
-2%
78
-12%
86
-3%
Black Level *
0.29
0.22
24%
0.208
28%
0.28
3%
Contrast
1121
1868
67%
1346
20%
1016
-9%
Colorchecker DeltaE2000 *
3.2
1.8
44%
3.97
-24%
2.07
35%
Colorchecker DeltaE2000 max. *
6.2
4.1
34%
8.29
-34%
3.75
40%
Colorchecker DeltaE2000 calibrated *
1.1
1
9%
3.42
-211%
2.05
-86%
Greyscale DeltaE2000 *
4.4
2.5
43%
2.83
36%
1.7
61%
Gamma
2.21 100%
2.26 97%
2.34 94%
2.17 101%
CCT
7430 87%
6448 101%
6556 99%
6627 98%
Color Space (Percent of AdobeRGB 1998)
62.9
64.7
3%
56
-11%
61.7
-2%
Color Space (Percent of sRGB)
96.6
99.3
3%
85
-12%
95.8
-1%
Total Average (Program / Settings)
9% / 20%
2% / -15%
18% / 6%

* ... smaller is better

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
32.8 ms ... rise ↗ and fall ↘ combined↗ 16.4 ms rise
↘ 16.4 ms fall
The screen shows slow response rates in our tests and will be unsatisfactory for gamers.
In comparison, all tested devices range from 0.8 (minimum) to 240 (maximum) ms. » 85 % of all devices are better.
This means that the measured response time is worse than the average of all tested devices (24.4 ms).
       Response Time 50% Grey to 80% Grey
54.4 ms ... rise ↗ and fall ↘ combined↗ 26.8 ms rise
↘ 27.6 ms fall
The screen shows slow response rates in our tests and will be unsatisfactory for gamers.
In comparison, all tested devices range from 0.8 (minimum) to 636 (maximum) ms. » 89 % of all devices are better.
This means that the measured response time is worse than the average of all tested devices (38.7 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: 51 % of all tested devices do not use PWM to dim the display. If PWM was detected, an average of 17507 (minimum: 5 - maximum: 2500000) Hz was measured.

Color-space coverage (sRGB) - 96.9%
Color-space coverage (sRGB) - 96.9%
Color-space coverage (AdobeRGB) - 62.9%
Color-space coverage (AdobeRGB) - 62.9%

Our analysis with the i1Pro 2 X-Rite measurement device attests the display with a very good color-space coverage of about 97% in the sRGB and almost 63% in the AdobeRGB color space. At 1121:1, the contrast ratio is also good, although some competing devices do even better here. The same goes for the black value of 0.29 cd/m².

The CalMAN analysis also shows that the display reproduces colors with too little of the red color content and an elevated blue color content. However, you can almost completely remedy this problem by calibration. You can download the corresponding ICC file in the window at the top right next to the schematic on the brightness distribution. 

In addition to a high stability of the viewing angles, the touchscreen of the Lifebook U939X is also characterized by its matte surface. In combination with the good brightness value, the Fujitsu convertible can therefore also be used easily outdoors even in direct sunlight.

CalMAN - Color Accuracy
CalMAN - Color Accuracy
CalMAN - Grayscale
CalMAN - Grayscale
CalMAN - Saturation
CalMAN - Saturation
CalMAN - Color Accuracy (calibrated)
CalMAN - Color Accuracy (calibrated)
CalMAN - Grayscale (calibrated)
CalMAN - Grayscale (calibrated)
CalMAN - Saturation (calibrated)
CalMAN - Saturation (calibrated)
Screen bleeding
Screen bleeding
Viewing-angle stability
Viewing-angle stability
Using it outdoors
Using it outdoors

Performance - Whiskey Lake is still suitable for everyday tasks

With the Lifebook U939X, Fujitsu mainly targets business users. The configuration with an Intel Core i7-8665U, 16 GB of RAM, and an SSD with up to 1 TB as the currently highest option does not allow for any graphically demanding applications, since the internal Intel UHD Graphics 620 is too weak for that. However, it still profits significantly from a dual-channel configuration of the working memory as is also used in our test unit. For office applications and simple image-processing tasks, the available hardware is more than sufficient.

Processor

The Intel Core i5-8265U used here is a quad-core processor that runs at core speeds between 1.6 and 3.9 GHz. How long high clock speeds can be maintained depends significantly on the built-in cooling system. Our constant load test shows that the CPU in the Fujitsu Lifebook U939X starts up with a very good value, which then very quickly drops by about 12%. However, the constant performance of the processor is still at a decent level, as the comparison with the HP Elite Dragonfly, for example, shows.

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Fujitsu Lifebook U939X Intel Core i5-8265U, Intel Core i5-8265U: Ø492 (486.03-559.89)
HP Elite Dragonfly-8MK79EA Intel Core i5-8265U, Intel Core i5-8265U: Ø413 (406.64-496.34)
Asus ZenBook Flip 14 UX463FA-AI039T Intel Core i5-10210U, Intel Core i5-10210U: Ø694 (572.34-716.85)
Lenovo ThinkPad X1 Yoga 20SA000GUS Intel Core i7-10510U, Intel Core i7-10510U: Ø605 (498.15-760.43)

In most of the CPU performance tests, the results of the Intel Core i5-8265U in the Lifebook U939X remain slightly below the average of other devices with this CPU we tested. Only in a few single disciplines, such as the Cinebench R20 single-core test, is the Fujitsu convertible able to score slightly above average.

Cinebench R20: CPU (Single Core) | CPU (Multi Core)
Cinebench R15: CPU Single 64Bit | CPU Multi 64Bit
Blender 2.79: BMW27 CPU
7-Zip 18.03: 7z b 4 -mmt1 | 7z b 4
Geekbench 5.1 / 5.2: 64 Bit Single-Core Score | 64 Bit Multi-Core Score
HWBOT x265 Benchmark v2.2: 4k Preset
LibreOffice : 20 Documents To PDF
R Benchmark 2.5: Overall mean
Cinebench R20 / CPU (Single Core) - CPU (Single Core)
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
451 Points ∼100% +14%
Fujitsu Lifebook U939X
Intel Core i5-8265U
397 Points ∼88%
Average Intel Core i5-8265U
  (325 - 403, n=15)
389 Points ∼86% -2%
Average of class Convertible
  (78 - 496, n=53)
371 Points ∼82% -7%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U
370 Points ∼82% -7%
Cinebench R20 / CPU (Multi Core) - CPU (Multi Core)
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
1563 Points ∼100% +36%
Average of class Convertible
  (200 - 2829, n=53)
1271 Points ∼81% +11%
Average Intel Core i5-8265U
  (972 - 1564, n=15)
1267 Points ∼81% +10%
Fujitsu Lifebook U939X
Intel Core i5-8265U
1148 Points ∼73%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U
1038 Points ∼66% -10%
Cinebench R15 / CPU Single 64Bit - CPU Single 64Bit
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
184 Points ∼100% +16%
Asus ZenBook Flip 14 UX463FA-AI039T
Intel Core i5-10210U
163 Points ∼89% +3%
Fujitsu Lifebook U939X
Intel Core i5-8265U
159 Points ∼86%
Average Intel Core i5-8265U
  (111 - 164, n=35)
155 Points ∼84% -3%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U
146 Points ∼79% -8%
Average of class Convertible
  (19 - 213, n=342)
112 Points ∼61% -30%
Cinebench R15 / CPU Multi 64Bit - CPU Multi 64Bit
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
760 (515.14min - 740.66max) Points ∼100% +36%
Asus ZenBook Flip 14 UX463FA-AI039T
Intel Core i5-10210U
715 Points ∼94% +28%
Average Intel Core i5-8265U
  (457 - 750, n=38)
592 Points ∼78% +6%
Fujitsu Lifebook U939X
Intel Core i5-8265U
559 (487.52min - 492.16max) Points ∼74%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U
496 (406.64min - 496.34max) Points ∼65% -11%
Average of class Convertible
  (33 - 1049, n=353)
342 Points ∼45% -39%
Blender 2.79 / BMW27 CPU - BMW27 CPU
Average of class Convertible
  (447 - 5811, n=44)
1380 Seconds * ∼100% -50%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U
1039 Seconds * ∼75% -13%
Fujitsu Lifebook U939X
Intel Core i5-8265U
918 Seconds * ∼67%
Average Intel Core i5-8265U
  (769 - 1098, n=14)
888 Seconds * ∼64% +3%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
718 Seconds * ∼52% +22%
7-Zip 18.03 / 7z b 4 -mmt1 - 7z b 4 -mmt1
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
4609 MIPS ∼100% +16%
Average Intel Core i5-8265U
  (3780 - 4195, n=14)
4052 MIPS ∼88% +2%
Average of class Convertible
  (1307 - 5167, n=43)
3969 MIPS ∼86% 0%
Fujitsu Lifebook U939X
Intel Core i5-8265U
3962 MIPS ∼86%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U
3885 MIPS ∼84% -2%
7-Zip 18.03 / 7z b 4 - 7z b 4
Average Intel Core i5-8265U
  (13731 - 18802, n=14)
16206 MIPS ∼100% +4%
Average of class Convertible
  (3541 - 31114, n=44)
15819 MIPS ∼98% +2%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
15727 MIPS ∼97% +1%
Fujitsu Lifebook U939X
Intel Core i5-8265U
15564 MIPS ∼96%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U
13812 MIPS ∼85% -11%
Geekbench 5.1 / 5.2 / 64 Bit Single-Core Score - 64 Bit Single-Core Score
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
1246 Points ∼100% +20%
Average Intel Core i5-8265U
  (1040 - 1047, n=3)
1043 Points ∼84% 0%
Fujitsu Lifebook U939X
Intel Core i5-8265U
1040 Points ∼83%
Average of class Convertible
  (233 - 1566, n=29)
1017 Points ∼82% -2%
Geekbench 5.1 / 5.2 / 64 Bit Multi-Core Score - 64 Bit Multi-Core Score
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
4287 Points ∼100% +16%
Fujitsu Lifebook U939X
Intel Core i5-8265U
3681 Points ∼86%
Average Intel Core i5-8265U
  (3442 - 3681, n=3)
3564 Points ∼83% -3%
Average of class Convertible
  (770 - 5443, n=29)
3551 Points ∼83% -4%
HWBOT x265 Benchmark v2.2 / 4k Preset - 4k Preset
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
5.27 fps ∼100% +31%
Average Intel Core i5-8265U
  (3.38 - 4.8, n=14)
4.2 fps ∼80% +5%
Fujitsu Lifebook U939X
Intel Core i5-8265U
4.01 fps ∼76%
Average of class Convertible
  (0.58 - 8.81, n=44)
3.95 fps ∼75% -1%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U
3.51 fps ∼67% -12%
LibreOffice / 20 Documents To PDF - 20 Documents To PDF
Average of class Convertible
  (46.9 - 238, n=24)
87.1 s ∼100% +47%
Average Intel Core i5-8265U
  (59.4 - 67.8, n=3)
62.6 s ∼72% +5%
Fujitsu Lifebook U939X
Intel Core i5-8265U
59.4 s ∼68%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
53.7 s ∼62% -10%
R Benchmark 2.5 / Overall mean - Overall mean
Average of class Convertible
  (0.611 - 2.74, n=25)
1.004 sec * ∼100% -36%
Fujitsu Lifebook U939X
Intel Core i5-8265U
0.736 sec * ∼73%
Average Intel Core i5-8265U
  (0.72 - 0.736, n=3)
0.729 sec * ∼73% +1%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U
0.648 sec * ∼65% +12%

* ... smaller is better

Cinebench R15 CPU Multi 64Bit
559 Points
Cinebench R15 OpenGL 64Bit
50 fps
Cinebench R15 Ref. Match 64Bit
97.8 %
Cinebench R15 CPU Single 64Bit
159 Points
Help

System Performance

In the PCMark 10 system performance tests, the Fujitsu Lifebook U939X achieves results that are slightly above average. The large amount of working memory and the fast Samsung SSD probably share the responsibility for this. Correspondingly, the Windows convertible is distinguished by a smooth system operation in everyday operation. The operating system as well as programs and opening and closing of files all run smoothly without any annoying micro stutters. The same also goes for using it in the Windows 10 tablet mode.

You can find out in our CPU benchmark list how other convertibles fared in our tests.

PCMark 10
Digital Content Creation
Lenovo ThinkPad X1 Yoga 20SA000GUS
UHD Graphics 620, i7-10510U, WDC PC SN730 SDBQNTY-512GB
3433 Points ∼27% +17%
Asus ZenBook Flip 14 UX463FA-AI039T
UHD Graphics 620, i5-10210U, Kingston RBUSNS8154P3512GJ1
3257 Points ∼25% +11%
Fujitsu Lifebook U939X
UHD Graphics 620, i5-8265U, Samsung SSD PM981 MZVLB512HAJQ
2943 Points ∼23%
Average Intel Core i5-8265U, Intel UHD Graphics 620
  (2067 - 3210, n=29)
2917 Points ∼23% -1%
HP Elite Dragonfly-8MK79EA
UHD Graphics 620, i5-8265U, Intel Optane Memory H10 with Solid State Storage 32GB + 512GB HBRPEKNX0202A(L/H)
2667 Points ∼21% -9%
Average of class Convertible
  (605 - 5161, n=134)
2659 Points ∼21% -10%
Productivity
Lenovo ThinkPad X1 Yoga 20SA000GUS
UHD Graphics 620, i7-10510U, WDC PC SN730 SDBQNTY-512GB
7470 Points ∼72% +20%
Asus ZenBook Flip 14 UX463FA-AI039T
UHD Graphics 620, i5-10210U, Kingston RBUSNS8154P3512GJ1
6634 Points ∼64% +7%
Fujitsu Lifebook U939X
UHD Graphics 620, i5-8265U, Samsung SSD PM981 MZVLB512HAJQ
6219 Points ∼60%
Average Intel Core i5-8265U, Intel UHD Graphics 620
  (2941 - 6556, n=29)
6061 Points ∼58% -3%
HP Elite Dragonfly-8MK79EA
UHD Graphics 620, i5-8265U, Intel Optane Memory H10 with Solid State Storage 32GB + 512GB HBRPEKNX0202A(L/H)
5916 Points ∼57% -5%
Average of class Convertible
  (1121 - 7945, n=136)
5502 Points ∼53% -12%
Essentials
Lenovo ThinkPad X1 Yoga 20SA000GUS
UHD Graphics 620, i7-10510U, WDC PC SN730 SDBQNTY-512GB
10379 Points ∼91% +27%
HP Elite Dragonfly-8MK79EA
UHD Graphics 620, i5-8265U, Intel Optane Memory H10 with Solid State Storage 32GB + 512GB HBRPEKNX0202A(L/H)
8270 Points ∼72% +1%
Fujitsu Lifebook U939X
UHD Graphics 620, i5-8265U, Samsung SSD PM981 MZVLB512HAJQ
8170 Points ∼71%
Asus ZenBook Flip 14 UX463FA-AI039T
UHD Graphics 620, i5-10210U, Kingston RBUSNS8154P3512GJ1
8011 Points ∼70% -2%
Average Intel Core i5-8265U, Intel UHD Graphics 620
  (5073 - 8689, n=29)
7833 Points ∼68% -4%
Average of class Convertible
  (2489 - 10546, n=136)
7304 Points ∼64% -11%
Score
Lenovo ThinkPad X1 Yoga 20SA000GUS
UHD Graphics 620, i7-10510U, WDC PC SN730 SDBQNTY-512GB
4611 Points ∼57% +21%
Asus ZenBook Flip 14 UX463FA-AI039T
UHD Graphics 620, i5-10210U, Kingston RBUSNS8154P3512GJ1
3995 Points ∼49% +5%
Fujitsu Lifebook U939X
UHD Graphics 620, i5-8265U, Samsung SSD PM981 MZVLB512HAJQ
3805 Points ∼47%
Average Intel Core i5-8265U, Intel UHD Graphics 620
  (2247 - 3985, n=29)
3705 Points ∼46% -3%
HP Elite Dragonfly-8MK79EA
UHD Graphics 620, i5-8265U, Intel Optane Memory H10 with Solid State Storage 32GB + 512GB HBRPEKNX0202A(L/H)
3636 Points ∼45% -4%
Average of class Convertible
  (872 - 5214, n=137)
3358 Points ∼41% -12%
PCMark 10 Score
3805 points
Help

DPC Latencies

Since the Fujitsu Lifebook U939X shows only relatively few latencies in our test, it should be well-suited for tasks such as real-time audio.

LatencyMon - Statistics
LatencyMon - Statistics
LatencyMon - Drivers
LatencyMon - Drivers
DPC Latencies / LatencyMon - interrupt to process latency (max), Web, Youtube, Prime95
Lenovo ThinkPad X1 Yoga 20SA000GUS
UHD Graphics 620, i7-10510U, WDC PC SN730 SDBQNTY-512GB
1837.8 μs * ∼100% -228%
Fujitsu Lifebook U939X
UHD Graphics 620, i5-8265U, Samsung SSD PM981 MZVLB512HAJQ
560.7 μs * ∼31%
Asus ZenBook Flip 14 UX463FA-AI039T
UHD Graphics 620, i5-10210U, Kingston RBUSNS8154P3512GJ1
466 μs * ∼25% +17%

* ... smaller is better

Storage Solution

Fujitsu has equipped our test configuration of the Lifebook U939X with a fast SSD from Samsung. This offers very good read and write rates that have a correspondingly positive effect on the system operation. Therefore, the convertible does very well in our comparison.

You can find out about the performance of other storage solutions in our tests in our HDD/SSD benchmark list.

Fujitsu Lifebook U939X
Samsung SSD PM981 MZVLB512HAJQ
HP Elite Dragonfly-8MK79EA
Intel Optane Memory H10 with Solid State Storage 32GB + 512GB HBRPEKNX0202A(L/H)
Asus ZenBook Flip 14 UX463FA-AI039T
Kingston RBUSNS8154P3512GJ1
Lenovo ThinkPad X1 Yoga 20SA000GUS
WDC PC SN730 SDBQNTY-512GB
Average Samsung SSD PM981 MZVLB512HAJQ
 
Average of class Convertible
 
CrystalDiskMark 5.2 / 6
-10%
-39%
12%
-0%
-32%
Write 4K
158.5
88.04
-44%
54.61
-66%
152
-4%
127 (90.4 - 176, n=64)
-20%
102 (1.168 - 194, n=130)
-36%
Read 4K
47.62
132.15
178%
28.19
-41%
45.96
-3%
44 (28 - 61.3, n=63)
-8%
39.6 (0.536 - 191, n=129)
-17%
Write Seq
1573
502.98
-68%
839.9
-47%
2069
32%
1617 (112 - 2730, n=62)
3%
871 (27.9 - 2372, n=125)
-45%
Read Seq
1411
1306.33
-7%
905
-36%
1708
21%
1716 (501 - 2665, n=62)
22%
1170 (74.7 - 2677, n=124)
-17%
Write 4K Q32T1
366.1
237.3
-35%
409.5
12%
465.4
27%
413 (198 - 1707, n=64)
13%
295 (1.212 - 747, n=130)
-19%
Read 4K Q32T1
451.9
287.35
-36%
292.4
-35%
410.1
-9%
420 (230 - 1015, n=64)
-7%
303 (1.189 - 585, n=130)
-33%
Write Seq Q32T1
1985
1242.4
-37%
1038
-48%
2713
37%
2076 (1714 - 2994, n=64)
5%
1101 (18.4 - 3019, n=130)
-45%
Read Seq Q32T1
3451
2480.4
-28%
1607
-53%
3399
-2%
3130 (1772 - 3565, n=64)
-9%
1900 (68.9 - 3565, n=130)
-45%
AS SSD
-55%
-66%
-33%
-25%
-974%
Score Total
4097
1420
-65%
1786
-56%
3083
-25%
3966 (2348 - 5316, n=62)
-3%
1385 (25 - 5215, n=291)
-66%
Score Write
1672
580
-65%
601
-64%
1283
-23%
1780 (147 - 2992, n=62)
6%
460 (4 - 2021, n=291)
-72%
Score Read
1627
566
-65%
804
-51%
1205
-26%
1451 (752 - 2125, n=62)
-11%
621 (10 - 2545, n=291)
-62%
Access Time Write *
0.027
0.045
-67%
0.072
-167%
0.07
-159%
0.0834 (0.025 - 2.52, n=62)
-209%
1.766 (0.021 - 291, n=296)
-6441%
Access Time Read *
0.051
0.078
-53%
0.074
-45%
0.055
-8%
0.0509 (0.029 - 0.103, n=62)
-0%
1.942 (0.029 - 433, n=292)
-3708%
4K-64 Write
1341.75
438.47
-67%
482.91
-64%
989.83
-26%
1505 (96.2 - 2716, n=62)
12%
330 (0.044 - 1651, n=296)
-75%
4K-64 Read
1301.29
393.74
-70%
643.83
-51%
969.84
-25%
1203 (530 - 1823, n=62)
-8%
490 (0.096 - 2280, n=296)
-62%
4K Write
143.79
110.71
-23%
52.67
-63%
154.92
8%
112 (1.76 - 146, n=62)
-22%
73.1 (0.2 - 175, n=296)
-49%
4K Read
53.88
62.34
16%
26.65
-51%
41.38
-23%
50.5 (31.7 - 61, n=62)
-6%
30.6 (0.39 - 76, n=296)
-43%
Seq Write
1864.31
305
-84%
652.81
-65%
1379.77
-26%
1637 (487 - 2564, n=62)
-12%
502 (18.5 - 2441, n=300)
-73%
Seq Read
2723.21
1096
-60%
1336.41
-51%
1938.8
-29%
1975 (1030 - 2806, n=62)
-27%
952 (74.2 - 2888, n=299)
-65%
Total Average (Program / Settings)
-33% / -36%
-53% / -55%
-11% / -14%
-13% / -15%
-503% / -578%

* ... smaller is better

Samsung SSD PM981 MZVLB512HAJQ
CDM 5/6 Read Seq Q32T1: 3451 MB/s
CDM 5/6 Write Seq Q32T1: 1985 MB/s
CDM 5/6 Read 4K Q32T1: 451.9 MB/s
CDM 5/6 Write 4K Q32T1: 366.1 MB/s
CDM 5 Read Seq: 1411 MB/s
CDM 5 Write Seq: 1573 MB/s
CDM 5/6 Read 4K: 47.62 MB/s
CDM 5/6 Write 4K: 158.5 MB/s

Constant Performance Reads: DiskSpd Read Loop, Queue Depth 8

02505007501000125015001750200022502500275030003250Tooltip
: Ø2453 (1918.14-3240.54)

Graphics Card

The display of image content is handled by the internal Intel UHD Graphics 620 graphics unit in the Lifebook U939X. It shares the working memory with the CPU and therefore profits from a dual-channel configuration as is used in our test unit. However, in the 3DMark 11 benchmark the result is not quite sufficient to reach the average value of other devices with the same GPU we tested. But the performance is still suitable for simple image-processing, casual games, or anything similar in everyday operation. 

You can find out how the Intel UHD Graphics 620 fares compared to other graphics cards in our GPU benchmark list.

3DMark 11 - 1280x720 Performance GPU
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel UHD Graphics 620, Intel Core i7-10510U
1986 Points ∼100% +16%
Asus ZenBook Flip 14 UX463FA-AI039T
Intel UHD Graphics 620, Intel Core i5-10210U
1855 Points ∼93% +8%
HP Elite Dragonfly-8MK79EA
Intel UHD Graphics 620, Intel Core i5-8265U
1789 Points ∼90% +5%
Average Intel UHD Graphics 620
  (1235 - 2006, n=225)
1743 Points ∼88% +2%
Fujitsu Lifebook U939X
Intel UHD Graphics 620, Intel Core i5-8265U
1711 Points ∼86%
Average of class Convertible
  (173 - 17421, n=366)
1516 Points ∼76% -11%
3DMark 11 Performance
1898 points
Help

Gaming Performance

The internal Intel UHD Graphics 620 graphics unit of the Lifebook U939X is not suitable for current games. Users should therefore limit themselves to very old or very simple games and even have to make do with lower graphics settings in those games. 

The gaming performance you can expect from the UHD Graphics 620 in various games is specified in our GPU games list.

The Witcher 3 - 1024x768 Low Graphics & Postprocessing
Average of class Convertible
  (4.69 - 145, n=60)
32.3 fps ∼100% +160%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U, Intel UHD Graphics 620
17.1 fps ∼53% +38%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U, Intel UHD Graphics 620
16 fps ∼50% +29%
Average Intel UHD Graphics 620
  (9.59 - 20.7, n=56)
15.9 fps ∼49% +28%
Fujitsu Lifebook U939X
Intel Core i5-8265U, Intel UHD Graphics 620
12.4 fps ∼38%
X-Plane 11.11
1920x1080 med (fps_test=2)
Average of class Convertible
  (3.48 - 62.9, n=37)
18.7 fps ∼100% +9%
Fujitsu Lifebook U939X
Intel Core i5-8265U, Intel UHD Graphics 620
17.2 fps ∼92%
Average Intel UHD Graphics 620
  (7.45 - 22.7, n=67)
13.9 fps ∼74% -19%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U, Intel UHD Graphics 620
10.6 fps ∼57% -38%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U, Intel UHD Graphics 620
9.84 fps ∼53% -43%
1280x720 low (fps_test=1)
Fujitsu Lifebook U939X
Intel Core i5-8265U, Intel UHD Graphics 620
26.2 fps ∼100%
Average of class Convertible
  (3.94 - 83.5, n=38)
25.9 fps ∼99% -1%
Average Intel UHD Graphics 620
  (8.45 - 31.1, n=68)
19.2 fps ∼73% -27%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U, Intel UHD Graphics 620
12.2 fps ∼47% -53%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U, Intel UHD Graphics 620
11.7 fps ∼45% -55%
Dota 2 Reborn
1920x1080 high (2/3)
Average of class Convertible
  (5.6 - 93.8, n=45)
24 fps ∼100% +20%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U, Intel UHD Graphics 620
22.4 (20.2min) fps ∼93% +12%
Asus ZenBook Flip 14 UX463FA-AI039T
Intel Core i5-10210U, Intel UHD Graphics 620
21.2 (19.6min) fps ∼88% +6%
Fujitsu Lifebook U939X
Intel Core i5-8265U, Intel UHD Graphics 620
20 (18.6min) fps ∼83%
Average Intel UHD Graphics 620
  (16.1 - 23.4, n=74)
20 fps ∼83% 0%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U, Intel UHD Graphics 620
18.7 (17.3min) fps ∼78% -6%
1366x768 med (1/3)
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U, Intel UHD Graphics 620
52.6 (39.7min) fps ∼100% +19%
Asus ZenBook Flip 14 UX463FA-AI039T
Intel Core i5-10210U, Intel UHD Graphics 620
51.6 (44.1min) fps ∼98% +17%
Average Intel UHD Graphics 620
  (33.7 - 57.1, n=74)
44.5 fps ∼85% +1%
Fujitsu Lifebook U939X
Intel Core i5-8265U, Intel UHD Graphics 620
44.1 (40min) fps ∼84%
Average of class Convertible
  (11.9 - 102, n=49)
42.6 fps ∼81% -3%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U, Intel UHD Graphics 620
40.2 (35.6min) fps ∼76% -9%
1280x720 min (0/3) fastest
Asus ZenBook Flip 14 UX463FA-AI039T
Intel Core i5-10210U, Intel UHD Graphics 620
83.2 (69.6min) fps ∼100% +21%
Lenovo ThinkPad X1 Yoga 20SA000GUS
Intel Core i7-10510U, Intel UHD Graphics 620
78.2 (69.4min) fps ∼94% +14%
Average Intel UHD Graphics 620
  (45.1 - 90, n=74)
72.5 fps ∼87% +6%
Fujitsu Lifebook U939X
Intel Core i5-8265U, Intel UHD Graphics 620
68.7 (60.3min) fps ∼83%
HP Elite Dragonfly-8MK79EA
Intel Core i5-8265U, Intel UHD Graphics 620
66.4 (59min) fps ∼80% -3%
Average of class Convertible
  (18.3 - 113, n=49)
65.8 fps ∼79% -4%
low med. high ultra
The Witcher 3 (2015) 12.4 fps
Dota 2 Reborn (2015) 68.7 44.1 20 17.9 fps
X-Plane 11.11 (2018) 26.2 17.2 fps

Emissions and Power Management - A good battery life and an active fan

Noise Emissions

The fan of the Lifebook U939X likes to run and at times turns on audibly already when opening an Internet browser. The basic sound is an even whirring, which is not suitable for noise-sensitive surroundings. However, since the fan noise is even and does not vary, it can be ignored easily.

Noise Level

Idle
29.8 / 29.8 / 29.8 dB(A)
Load
33.5 / 36.3 dB(A)
  red to green bar
 
 
30 dB
silent
40 dB(A)
audible
50 dB(A)
loud
 
min: dark, med: mid, max: light   Audix TM1, Arta (15 cm distance)   environment noise: 29.8 dB(A)
dB(A) 0102030405060708090Deep BassMiddle BassHigh BassLower RangeMidsHigher MidsLower HighsMid HighsUpper HighsSuper Highs2029.73032.233.330.82527.927.329.126.827.43133.234.733.728.835.24030.535.739.527.932.95026.926.930.127.630.36323.123.927.524.829.98024.924.325.323.226.210026.825.225.425.728.512523.223.524.42324.416023.823.623.922.823.120022.52323.123.222.825022.622.62322.223.83152221.921.521.322.540021.621.121.120.721.150022.120.32119.920.563021.320.420.419.820.180021.519.320.819.319.4100021.919.120.718.319.1125024.419.521.21819.9160026.220.323.217.221.4200027.421.824.516.822.5250027.718.625.116.820.631502717.120.816.518.1400023.517.119.316.317.5500020.216.417.716.416.6630020.116.516.916.416.680001816.416.616.316.41000016.616.316.316.316.31250016.216.216.116.116.11600015.915.915.915.916SPL36.331.133.529.831.7N2.31.51.81.31.6median 22.1median 19.5median 21median 18median 20.1Delta1.82.92.22.62.5hearing rangehide median Fan NoiseFujitsu Lifebook U939X

Temperatures

Stress test
Stress test

In our test, the Fujitsu Lifebook U939X reaches surface temperatures up to 46.7 °C (116°F). The warmest spot is at the bottom in the center towards the back, causing the convertible to feel merely warm on the sides, so you can still hold it comfortably even under load.

During our stress test that lasted about one hour, the temperatures inside the Fujitsu convertible rose up to 95 °C (203 °F). Even though the fans were able to lower this value to an average of about 83 °C (181°) until the end of the test, at barely above 1 GHz, the clock speeds of the CPU remained significantly below the basic clock speed of 1.6 GHz. However, since the system was able to recover quickly after the end of our demanding test, users should not have to expect any limitations due to the temperatures being too high.

Max. Load
 41.1 °C
106 F
43.5 °C
110 F
39.7 °C
103 F
 
 37.5 °C
100 F
39.3 °C
103 F
29.8 °C
86 F
 
 27.9 °C
82 F
30.1 °C
86 F
27.6 °C
82 F
 
Maximum: 43.5 °C = 110 F
Average: 35.2 °C = 95 F
44.2 °C
112 F
46.7 °C
116 F
40.8 °C
105 F
29.4 °C
85 F
39.6 °C
103 F
36.6 °C
98 F
26.6 °C
80 F
28.3 °C
83 F
28.7 °C
84 F
Maximum: 46.7 °C = 116 F
Average: 35.7 °C = 96 F
Power Supply (max.)  35.2 °C = 95 F | Room Temperature 22.1 °C = 72 F | Voltcraft IR-900
(±) The average temperature for the upper side under maximal load is 35.2 °C / 95 F, compared to the average of 30.3 °C / 87 F for the devices in the class Convertible.
(±) The maximum temperature on the upper side is 43.5 °C / 110 F, compared to the average of 35.3 °C / 96 F, ranging from 21.8 to 55.7 °C for the class Convertible.
(-) The bottom heats up to a maximum of 46.7 °C / 116 F, compared to the average of 36.5 °C / 98 F
(+) In idle usage, the average temperature for the upper side is 25.9 °C / 79 F, compared to the device average of 30.3 °C / 87 F.
(+) The palmrests and touchpad are cooler than skin temperature with a maximum of 30.1 °C / 86.2 F and are therefore cool to the touch.
(±) The average temperature of the palmrest area of similar devices was 28.9 °C / 84 F (-1.2 °C / -2.2 F).
Heat map under load - top
Heat map under load - top
Heat map under load - bottom
Heat map under load - bottom

Speakers

The speakers of the Fujitsu Lifebook U939X produce a medium volume and a sound spectrum that is dominated by higher mids. While this makes them suitable for reproduction of voice content, users should choose external speakers or headphones for media content. Those can be connected to the Windows convertible using the available 3.5-mm audio port as well as other methods.

dB(A) 0102030405060708090Deep BassMiddle BassHigh BassLower RangeMidsHigher MidsLower HighsMid HighsUpper HighsSuper Highs2033.330.92526.8273128.832.64027.929.65027.628.66324.829.38023.225.910025.725.81252324.216022.825.320023.231.325022.23931521.342.340020.745.150019.94763019.851.580019.360.3100018.361.912501868.1160017.266.9200016.860.3250016.859.8315016.558.9400016.363.1500016.456.4630016.452.7800016.3471000016.346.81250016.141.51600015.936.6SPL29.873.9N1.327.4median 18median 47Delta2.611.535.335.132.931.831.83236.535.132.428.93328.936.328.848.32761.52752.924.860.92462.822.763.32269.521.267.82174.82075.919.472.718.97117.770.117.86917.671.817.668.117.671.417.673.717.670.417.571.617.671.617.669.617.459.717.583.630.662.51.5median 69.6median 17.84.62.4hearing rangehide median Pink NoiseFujitsu Lifebook U939XApple MacBook 12 (Early 2016) 1.1 GHz
Frequency diagram (checkboxes can be checked and unchecked to compare devices)
Fujitsu Lifebook U939X audio analysis

(±) | speaker loudness is average but good (73.9 dB)
Bass 100 - 315 Hz
(-) | nearly no bass - on average 15.7% lower than median
(±) | linearity of bass is average (11.4% delta to prev. frequency)
Mids 400 - 2000 Hz
(±) | higher mids - on average 11.1% higher than median
(±) | linearity of mids is average (14.5% delta to prev. frequency)
Highs 2 - 16 kHz
(±) | higher highs - on average 8% higher than median
(±) | linearity of highs is average (10.8% delta to prev. frequency)
Overall 100 - 16.000 Hz
(-) | overall sound is not linear (38.2% difference to median)
Compared to same class
» 95% of all tested devices in this class were better, 2% similar, 3% worse
» The best had a delta of 10%, average was 22%, worst was 53%
Compared to all devices tested
» 98% of all tested devices were better, 1% similar, 1% worse
» The best had a delta of 3%, average was 21%, worst was 65%

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, 1% similar, 97% worse
» The best had a delta of 8%, average was 20%, worst was 50%
Compared to all devices tested
» 2% of all tested devices were better, 0% similar, 98% worse
» The best had a delta of 3%, average was 21%, worst was 65%

Power Consumption

Our measurements attest the Fujitsu Lifebook U939X with an average power consumption of 5.9 watts during idle operation and up to 50.5 watts under load. This makes the convertible a device with slightly high power consumption for its class.

The included 65-Watt power supply is sufficiently large to ensure enough power for the device.

Power Consumption
Off / Standbydarklight 0.17 / 0.55 Watt
Idledarkmidlight 3.4 / 5.9 / 9.2 Watt
Load midlight 34.1 / 50.5 Watt
 color bar
Key: min: dark, med: mid, max: light        Metrahit Energy

Battery Life

In our realistic WLAN test, the Lifebook U939X demonstrates that it is able to make good use of its 50-Wh battery. With a battery life of about 10.5 hours, it is able to move ahead of our test field, leaving even competing devices with slightly higher capacities behind.

Battery Runtime - WiFi Websurfing 1.3
Fujitsu Lifebook U939X
i5-8265U, UHD Graphics 620, 50 Wh
627 min ∼24%
HP Elite Dragonfly-8MK79EA
i5-8265U, UHD Graphics 620, 56.2 Wh
605 min ∼23% -4%
Lenovo ThinkPad X1 Yoga 20SA000GUS
i7-10510U, UHD Graphics 620, 51 Wh
553 min ∼21% -12%
Average of class Convertible
  (153 - 1141, n=290)
467 min ∼18% -26%
Asus ZenBook Flip 14 UX463FA-AI039T
i5-10210U, UHD Graphics 620, 50 Wh
461 min ∼17% -26%
Battery Runtime
NBC WiFi Websurfing Battery Test 1.3
10h 27min

Pros

+ very good, non-reflective touchscreen
+ input stylus included
+ many connections
+ good system performance
+ LTE module

Cons

- mediocre keyboard
- touchpad makes slight clattering noises
- no Wi-Fi 6
- working memory cannot be expanded

Verdict - Fujitsu's Lifebook U939X could be even better

In review: Fujitsu Lifebook U939X. Test unit provided by Fujitsu Germany.
In review: Fujitsu Lifebook U939X. Test unit provided by Fujitsu Germany.

While the Fujitsu Lifebook U939X leaves a good impression with us, there are also some reasons for complaints. On the positive side, there is a very good touchscreen that not only stands out with its good display values but also with its non-reflective surface. The connection equipment already offers basically a good selection, but with the two Thunderbolt 3 ports, users get the additional freedom to create their own connections by using adapters. The whole package is also rounded by a good battery life.

The Lifebook U939X would be an almost perfect convertible, if Fujitsu would improve on the touchpad and keyboard.

Starting in July, there should be processors of the Comet Lake generation available in Fujitsu's Lifebooks, so the fact that the CPU is currently not up to date anymore does not matter that much. The performance is at a good level and it might still be a good choice for buyers of remainders if the price is right. Despite the lack of Wi-Fi 6 support, the WLAN performance is also still suitable for everyday operation.

However, the otherwise very good convertible has to accept significant negative marks for its keyboard and the touchpad. The soft feedback while typing and the easily clattering noise of the mouse replacement do not leave a good impression for a device in this price range. Users therefore need to weigh whether the positive characteristics of the Fujitsu Lifebook U939X are more important to them than the negative points mentioned.

Fujitsu Lifebook U939X - 06/29/2020 v7
Mike Wobker

Chassis
79 / 98 → 81%
Keyboard
72%
Pointing Device
82%
Connectivity
65 / 75 → 87%
Weight
75 / 20-75 → 99%
Battery
88%
Display
86%
Games Performance
44 / 78 → 56%
Application Performance
83 / 85 → 98%
Temperature
90%
Noise
97%
Audio
48 / 91 → 53%
Camera
37 / 85 → 44%
Average
73%
85%
Convertible - Weighted Average

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> Notebook / Laptop Reviews and News > Reviews > Fujitsu Lifebook U939X Review: A business convertible with a lot of functionalities
Mike Wobker, 2020-07- 6 (Update: 2020-07- 7)
Mike Wobker
Editor of the original article: Mike Wobker - Editor
I made my first IT walking attempts on a 386 with 4 MB of RAM. After that followed various PCs and notebooks, which I looked after and repaired in my circle of friends and acquaintances. After an apprenticeship as a telecommunications systems engineer and several years of professional experience, I graduated with a bachelor's degree in industrial engineering. Today I live out my fascination for IT, technology and mobile devices by writing test reports. In my free time I like to devote myself to vegan cooking and spend time with my family, which includes a whole range of animal roommates.