Notebookcheck

CAT S31 Smartphone Review

Mike Wobker (translated by Karim Allaoui), 01/03/2018

Smart industry phone. The rugged smartphones from Caterpillar, a manufacturer of construction equipment, are entering the next round. On the outside everything stays as it is, but on the inside some improvements have been made. In our test we found out what exactly is new about the extreme outdoor smartphone Cat S31.

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For more than five years, the licensee "Catphone Mobile Ltd" has been producing rugged smartphones with the logo of the Caterpillar construction machinery company. The company's phones are certified to industry standard IP68 and military standard MIL-SPEC 810G. The manufacturer even claims that the standards of certification are exceeded in its own laboratories. However, as our test of the CAT S40 from 2015 showed, these devices are by no means indestructible.

However, CAT is not alone in the market of rugged outdoor phones and with a price of over 300 Euros (~$360), the S31 is not exactly among the cheaper competitors either. In addition to the Blackview BV8000 Pro, the CAT S31 has to compete with the Samsung Galaxy XCover 4, the S30 from Nomu and the AGM A8. The prices of competing devices range from a relatively inexpensive 180 Euros (~$216) (AGM A8) to 330 Euros (~$399) (CAT and Blackview).

CAT S31
Graphics adapter
Memory
2048 MB 
Display
4.7 inch 16:9, 1280 x 720 pixel 312 PPI, capacitive, IPS, glossy: yes
Storage
16 GB eMMC Flash, 16 GB 
, 13 GB free
Connections
1 USB 2.0, Audio Connections: 3.5 mm jack connection, Card Reader: microSD, Brightness Sensor, Sensors: Accelerometer, Proximity Sensor, Ambient Light Sensor, Compass
Networking
802.11 b/g/n (b/g/n), Bluetooth 4.1, GSM, GPRS, EDGE, WCDMA, UMTS, HSPA, HSPA+, LTE (Cat. 4), Dual SIM, LTE, GPS
Size
height x width x depth (in mm): 12.6 x 146 x 74.4 ( = 0.5 x 5.75 x 2.93 in)
Battery
4000 mAh Lithium-Ion, Talk time 3G (according to manufacturer): 30 h, Standby 3G (according to manufacturer): 912 h
Operating System
Android 7.1 Nougat
Camera
Primary Camera: 8 MPix
Secondary Camera: 2 MPix
Additional features
Speakers: Mono, Keyboard: onscreen, Keyboard Light: yes, 24 Months Warranty, fanless, ruggedized
Weight
200 g ( = 7.05 oz / 0.44 pounds), Power Supply: 85 g ( = 3 oz / 0.19 pounds)
Price
330 Euro

 

With a diagonal screen size of 4.7-inches, the CAT S31 is the smallest device in the reference group, but its robust case makes it very bulky. This is typical for such stable devices and should therefore not be considered negative. The smartphone is just as thick as larger devices in this class, not least because of the generously sized battery.

With IP68 certification and the military standard MIL-SPEC 810G, the S31 is suitable for almost all environments. It is dustproof, at 1.20 meters water depth up to 35 minutes waterproof and fall-proof from heights of up to 1.80 meters. With many ripples and edges, it is almost impossible for the smartphone to slip out of your hand. The manufacturer Catphone calls the appearance of the S31 an Easy-Grip-Design.

The device also feels very sturdy in the hand and has no flaws in its workmanship. Each port is equipped with a rubberized closure and the physical buttons are firmly seated in their respective positions.

Size Comparison

Features

Like in the CAT S40 from two years ago, a Qualcomm Snapdragon 210 MSM8909 with the Adreno 304 graphics unit is used in the CAT S31. This entry-level SoC is sufficient to operate the Android 7.1 Nougat system smoothly. But for demanding applications, the chip was not suitable even in the year of its release. Therefore users should choose simpler apps. With 2 GB of memory and 16 GB flash memory, there is enough capacity for most applications. Only graphically demanding games should be avoided. A microSD card can be used to expand the internal memory up to 128 GB.

Memory and SIM-card slots are accessible from the outside and are protected by flaps. The SIM-card slot in particular is very tightly closed and can only be opened with a flat screwdriver. The buttons on the left and right sides of the device can also easily be felt when wearing gloves. The feedback for these buttons is very clear. In addition to the power button and volume control, the S31 is equipped with a freely assignable button. In the respective menu, different actions can be selected for both short and long presses of the button. For example, apps can be started, calls answered or notifications sent. Alternatively, the button can also receive a push-to-talk assignment.


Left side: power button, programmable button
Left side: power button, programmable button
Top side: headset connection
Top side: headset connection
Right side: microSD, dual-SIM, volume buttons
Right side: microSD, dual-SIM, volume buttons
Bottom side: 1x Micro-USB (main power supply)
Bottom side: 1x Micro-USB (main power supply)
Right side: microSD (opened), dual-SIM (opened), volume buttons
Right side: microSD (opened), dual-SIM (opened), volume buttons
Bottom side: 1x Micro-USB (main power supply, open)
Bottom side: 1x Micro-USB (main power supply, open)

Software

The CAT S31 is shipped with Android 7.1 Nougat and provides the user with a very tidy interface. In addition to a few preinstalled programs, Catphone provides the company's own app Toolbox. This is an app store in which the manufacturer has collected apps sorted into categories that are specifically tailored to the construction industry, outdoor pursuits or sports. Of course, the Google Play Store is also available. We could not find any information about an update to Android 8.0 Oreo though.

Communication and GPS

Only a slow b/g/n WLAN adapter is available in our test device. This means that the S31 only achieves below-average transmission rates, but it is still able to place itself in the mid-range of the comparison devices. The situation is slightly better with mobile radio reception. This smartphone can cope with almost any network, with 4G availability depending on the region. There is an extra model for the North American region. The reception is fine in all networks and the voice quality is very good. We particularly liked the speaker for hands-free talking. Volume and sound quality are also suitable for louder environments.

Networking
iperf3 Client (receive) TCP 1 m 4M x10
Nomu S30
Mali-T860 MP2, Helio P10 MT6755, 64 GB eMMC Flash
101 MBit/s ∼100% +143%
Blackview BV8000 Pro
Mali-T880 MP2, Helio P20 MT6757, 64 GB eMMC Flash
101 MBit/s ∼100% +143%
Samsung Galaxy XCover 4
Mali-T720, 7570 Quad, 16 GB eMMC Flash
49.2 MBit/s ∼49% +18%
CAT S31
Adreno 304, 210 MSM8909, 16 GB eMMC Flash
41.6 MBit/s ∼41%
AGM A8
Adreno 306, 410 MSM8916, 32 GB eMMC Flash
26.9 MBit/s ∼27% -35%
iperf3 Client (transmit) TCP 1 m 4M x10
Nomu S30
Mali-T860 MP2, Helio P10 MT6755, 64 GB eMMC Flash
102 MBit/s ∼100% +160%
Blackview BV8000 Pro
Mali-T880 MP2, Helio P20 MT6757, 64 GB eMMC Flash
96.1 MBit/s ∼94% +145%
CAT S31
Adreno 304, 210 MSM8909, 16 GB eMMC Flash
39.3 MBit/s ∼39%
Samsung Galaxy XCover 4
Mali-T720, 7570 Quad, 16 GB eMMC Flash
37.9 MBit/s ∼37% -4%
AGM A8
Adreno 306, 410 MSM8916, 32 GB eMMC Flash
18.4 MBit/s ∼18% -53%
Outdoor GPS reception
Outdoor GPS reception
GPS reception in buildings
GPS reception in buildings

The GPS receiver of the S31 offers a relatively accurate location determination in open air. Only with jagged curves and abrupt changes of direction does the distance recording become somewhat inaccurate. At the end of our test track, the smartphone measures only 20 meters less than the Garmin 500 navigation device.

But the S31 does not only rely on GPS, it also uses GLONASS, aGPS and Beidou. In closed rooms, however, this does not change the bad satellite reception. Using the "GPS-Test" tool, our test device only has an accuracy of 80 meters.

GPS Cat S31
GPS Cat S31
GPS Cat S31
GPS Cat S31
GPS Cat S31
GPS Cat S31
GPS Garmin Edge 500
GPS Garmin Edge 500
GPS Garmin Edge 500
GPS Garmin Edge 500
GPS Garmin Edge 500
GPS Garmin Edge 500

Phone Functions and Voice Quality

In the S31, the standard Android phone app is used. The virtual keys are just big enough to be operated while wearing gloves. Called parties clearly understand the person they are talking to and our test device also distinctly reproduces speech. Using the supplied headset, calls can be made clearly and precisely as well.

Cameras

8 MP main camera
8 MP main camera
2 MP front camera
2 MP front camera

The cameras of the S31 remain at the same level as those of the CAT S40 from 2015. With an 8 MP main and 2 MP front camera, our test device is only below average. Most comparable models offer at least 13 megapixels. 

Even in poor lighting conditions, the main camera can take suitable pictures. However, a steady hand is absolutely necessary, otherwise noise and blurred edges can be seen on the photos. As a webcam, the 2-MP front camera is barely usable. Colors appear very pale and the camera can only transmit movements properly in very good light. 

Image Comparison

Choose a scene and navigate within the first image. One click changes the position on touchscreens. One click on the zoomed-in image opens the original in a new window. The first image shows the scaled photograph of the test device.

Scene 1Scene 2Scene 3
click to load images

With the main camera, the S31 does not match any color of our ColorChecker Passport perfectly. Light colors are displayed too dark and dark colors are too bright. However, objects in the center of the image are sharply displayed. Borders and structures are visible even with reflections. A slight blurring occurs at the edges of our test images.

Accessories and Warranty

The scope of delivery of the S31 includes a headset in addition to the power supply. Some accessories are also available on the manufacturer's website. In addition to a car mount, car charger cable and a leather holster, Catphone also offers a rugged power bank in the style of robust outdoor smartphones. With a capacity of 10,000 mAh, it has two-and-a-half times the battery capacity of the S31.

Input Devices & Operation

Using the virtual keyboard, the S31 offers the usual range of functions of an Android system. Rotations of the device are carried out with a slight delay, but they do not interfere with general operation. The virtual keys are not easy to hit on the small display, even in the horizontal view. The input of long texts could be a stressful task, especially when wearing gloves. The touchscreen responds very well to touch. The system is also directly suitable for operation with gloves. The physical keys sit firmly in the case of the S31 and create the impression that they can be pressed very firmly. The triggering behavior is direct and the feedback from the buttons is also fine.

Display

Subpixel
Subpixel

Catphone equips the S31 with an IPS display which displays screen content at a resolution of 1280x720 pixels. With a screen diagonal of only 4.7-inches, this resolution is sufficient and pixelated edges can only be detected with very close inspection. Corning Gorilla Glass 3 is designed to protect the display. We took a risk and dropped the S31 several times, sometimes at waist height, sometimes from a position in front of the chest. Our test device could parry every fall without scratches. It did not matter whether the fall occurred on tiled floors or pavement slabs. The display of the CAT S40 could not withstand a fall.

722
cd/m²
773
cd/m²
751
cd/m²
726
cd/m²
784
cd/m²
754
cd/m²
728
cd/m²
779
cd/m²
736
cd/m²
Distribution of brightness
X-Rite i1Pro 2
Maximum: 784 cd/m² Average: 750.3 cd/m² Minimum: 36.9 cd/m²
Brightness Distribution: 92 %
Center on Battery: 784 cd/m²
Contrast: 1742:1 (Black: 0.45 cd/m²)
ΔE Color 4.28 | 0.4-29.43 Ø6.3
ΔE Greyscale 6.1 | 0.64-98 Ø6.5
98.1% sRGB (Calman 2D)
Gamma: 2.49
CAT S31
IPS, 1280x720, 4.7
AGM A8
IPS, 1280x720, 5
Nomu S30
IPS, 1920x1080, 5.5
Blackview BV8000 Pro
IPS, 1920x1080, 5
Samsung Galaxy XCover 4
IPS, 1280x720, 5
CAT S40
IPS, 960x540, 4.7
Screen
4%
-33%
-64%
-36%
-8%
Brightness middle
784
356
-55%
423
-46%
434
-45%
445
-43%
607
-23%
Brightness
750
343
-54%
421
-44%
414
-45%
437
-42%
579
-23%
Brightness Distribution
92
93
1%
93
1%
86
-7%
88
-4%
90
-2%
Black Level *
0.45
0.21
53%
0.26
42%
0.64
-42%
0.67
-49%
0.5
-11%
Contrast
1742
1695
-3%
1627
-7%
678
-61%
664
-62%
1214
-30%
Colorchecker DeltaE2000 *
4.28
3.7
14%
7.8
-82%
9.8
-129%
6.5
-52%
4.25
1%
Colorchecker DeltaE2000 max. *
8.75
8.3
5%
14.5
-66%
19.2
-119%
10.6
-21%
Greyscale DeltaE2000 *
6.1
1.9
69%
9.8
-61%
9.9
-62%
7.2
-18%
4.09
33%
Gamma
2.49 96%
2.5 96%
2.32 103%
2.64 91%
2.53 95%
2.61 92%
CCT
7175 91%
6412 101%
9828 66%
9219 71%
8274 79%
6959 93%
Color Space (Percent of AdobeRGB 1998)
71.2034
Color Space (Percent of sRGB)
94.1292

* ... smaller is better

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: 54 % of all tested devices do not use PWM to dim the display. If PWM was detected, an average of 8882 (minimum: 43 - maximum: 142900) Hz was measured.

Measurements confirm our subjective impression of the S31. Especially the outstanding brightness value provides an easily legible image outdoors and in sunny conditions. In combination with the good contrast, our test device only has to surrender to the overall display rating of the AGM A8, although the outdoor phone from AGM can only offer a considerably lower brightness value.

While the resolution of the S31 is lower than those of the comparable devices, screen content is displayed sharply. The slightly increased black value has no noticeable influence on the color representation. All in all, we received a positive impression of the display.

CalMAN - grayscale
CalMAN - grayscale
CalMAN - color space
CalMAN - color space
CalMAN - saturation
CalMAN - saturation
CalMAN - mixed colors
CalMAN - mixed colors

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
24.4 ms ... rise ↗ and fall ↘ combined↗ 13.6 ms rise
↘ 10.8 ms fall
The screen shows good response rates in our tests, but may be too slow for competitive gamers.
In comparison, all tested devices range from 0.8 (minimum) to 240 (maximum) ms. » 37 % of all devices are better.
This means that the measured response time is similar to the average of all tested devices (25.9 ms).
       Response Time 50% Grey to 80% Grey
42 ms ... rise ↗ and fall ↘ combined↗ 21 ms rise
↘ 21 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. » 53 % of all devices are better.
This means that the measured response time is similar to the average of all tested devices (41.4 ms).

Especially outdoors, the S31's display shines. This is not because of the glass surface, but because of its excellent visibility. Screen content is clearly visible from every angle and in all conceivable lighting conditions. None of the outdoor smartphones tested by us can even reach close to the brightness of our test device.

Stable viewing angles
Stable viewing angles
Outdoor use
Outdoor use

Performance

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The S31 is a purely practical device. The Qualcomm Snapdragon 210 MSM8909 with Adreno 304 as the graphics unit is over two years old and was only used as an entry-level SoC in 2015. However, with 2 GB of memory, Android 7.1 Nougat runs smoothly and for the intended purpose no more performance is required.

Compared to its rival devices, the S31 achieves below-average results. With regard to the CAT S40 in particular, it is clear that the current model would only be classified as an entry-level model in 2015.

AnTuTu v6 - Total Score (sort by value)
CAT S31
24865 Points ∼11%
AGM A8
26753 Points ∼12% +8%
Nomu S30
50904 Points ∼22% +105%
Blackview BV8000 Pro
64833 Points ∼28% +161%
Samsung Galaxy XCover 4
35379 Points ∼15% +42%
PCMark for Android
Work 2.0 performance score (sort by value)
CAT S31
2300 Points ∼22%
AGM A8
3701 Points ∼36% +61%
Nomu S30
3405 Points ∼33% +48%
Blackview BV8000 Pro
3801 Points ∼37% +65%
Samsung Galaxy XCover 4
3446 Points ∼33% +50%
Work performance score (sort by value)
CAT S31
3080 Points ∼30%
AGM A8
2920 Points ∼28% -5%
Nomu S30
3175 Points ∼31% +3%
Blackview BV8000 Pro
4477 Points ∼44% +45%
Samsung Galaxy XCover 4
4508 Points ∼44% +46%
CAT S40
2927 Points ∼29% -5%
BaseMark OS II
Web (sort by value)
CAT S31
10 Points ∼1%
AGM A8
557 Points ∼33% +5470%
Nomu S30
618 Points ∼36% +6080%
Blackview BV8000 Pro
736 Points ∼43% +7260%
Samsung Galaxy XCover 4
661 Points ∼39% +6510%
CAT S40
616 Points ∼36% +6060%
Graphics (sort by value)
CAT S31
256 Points ∼3%
AGM A8
306 Points ∼3% +20%
Nomu S30
670 Points ∼7% +162%
Blackview BV8000 Pro
1118 Points ∼12% +337%
Samsung Galaxy XCover 4
253 Points ∼3% -1%
CAT S40
260 Points ∼3% +2%
Memory (sort by value)
CAT S31
328 Points ∼7%
AGM A8
757 Points ∼16% +131%
Nomu S30
942 Points ∼20% +187%
Blackview BV8000 Pro
1236 Points ∼26% +277%
Samsung Galaxy XCover 4
1066 Points ∼22% +225%
CAT S40
408 Points ∼9% +24%
System (sort by value)
CAT S31
899 Points ∼9%
AGM A8
1161 Points ∼11% +29%
Nomu S30
2216 Points ∼22% +146%
Blackview BV8000 Pro
3052 Points ∼30% +239%
Samsung Galaxy XCover 4
1396 Points ∼14% +55%
CAT S40
792 Points ∼8% -12%
Overall (sort by value)
CAT S31
1 Points ∼0%
AGM A8
622 Points ∼14% +62100%
Nomu S30
964 Points ∼22% +96300%
Blackview BV8000 Pro
1327 Points ∼31% +132600%
Samsung Galaxy XCover 4
706 Points ∼16% +70500%
CAT S40
477 Points ∼11% +47600%
Geekbench 4.1/4.2
Compute RenderScript Score (sort by value)
Blackview BV8000 Pro
2929 Points ∼20%
64 Bit Multi-Core Score (sort by value)
CAT S31
1135 Points ∼4%
AGM A8
1383 Points ∼5% +22%
Blackview BV8000 Pro
4053 Points ∼14% +257%
Samsung Galaxy XCover 4
1855 Points ∼6% +63%
64 Bit Single-Core Score (sort by value)
CAT S31
437 Points ∼7%
AGM A8
515 Points ∼9% +18%
Blackview BV8000 Pro
851 Points ∼14% +95%
Samsung Galaxy XCover 4
629 Points ∼11% +44%
3DMark
2560x1440 Sling Shot Extreme (ES 3.1) Physics (sort by value)
CAT S31
560 Points ∼15%
Nomu S30
1182 Points ∼32% +111%
Blackview BV8000 Pro
1757 Points ∼48% +214%
Samsung Galaxy XCover 4
952 Points ∼26% +70%
2560x1440 Sling Shot Extreme (ES 3.1) Graphics (sort by value)
CAT S31
0 Points ∼0%
Nomu S30
351 Points ∼7%
Blackview BV8000 Pro
628 Points ∼12%
Samsung Galaxy XCover 4
85 Points ∼2%
2560x1440 Sling Shot Extreme (ES 3.1) (sort by value)
CAT S31
0 Points ∼0%
Nomu S30
416 Points ∼9%
Blackview BV8000 Pro
733 Points ∼15%
Samsung Galaxy XCover 4
107 Points ∼2%
2560x1440 Sling Shot OpenGL ES 3.0 Physics (sort by value)
AGM A8
739 Points ∼20%
Nomu S30
1114 Points ∼31%
Blackview BV8000 Pro
1764 Points ∼48%
Samsung Galaxy XCover 4
955 Points ∼26%
CAT S40
454 Points ∼12%
2560x1440 Sling Shot OpenGL ES 3.0 Graphics (sort by value)
AGM A8
43 Points ∼1%
Nomu S30
522 Points ∼6%
Blackview BV8000 Pro
905 Points ∼11%
Samsung Galaxy XCover 4
157 Points ∼2%
CAT S40
29 Points ∼0%
2560x1440 Sling Shot OpenGL ES 3.0 (sort by value)
AGM A8
54 Points ∼1%
Nomu S30
592 Points ∼9%
Blackview BV8000 Pro
1015 Points ∼16%
Samsung Galaxy XCover 4
193 Points ∼3%
CAT S40
37 Points ∼1%
1280x720 offscreen Ice Storm Unlimited Physics (sort by value)
CAT S31
6396 Points ∼8%
AGM A8
9082 Points ∼11% +42%
Nomu S30
12394 Points ∼16% +94%
Blackview BV8000 Pro
16603 Points ∼21% +160%
Samsung Galaxy XCover 4
11459 Points ∼15% +79%
CAT S40
6789 Points ∼9% +6%
1280x720 offscreen Ice Storm Unlimited Graphics Score (sort by value)
CAT S31
5042 Points ∼1%
AGM A8
3808 Points ∼1% -24%
Nomu S30
10373 Points ∼2% +106%
Blackview BV8000 Pro
14001 Points ∼3% +178%
Samsung Galaxy XCover 4
3985 Points ∼1% -21%
CAT S40
4014 Points ∼1% -20%
1280x720 offscreen Ice Storm Unlimited Score (sort by value)
CAT S31
5291 Points ∼3%
AGM A8
4372 Points ∼2% -17%
Nomu S30
10763 Points ∼5% +103%
Blackview BV8000 Pro
14506 Points ∼7% +174%
Samsung Galaxy XCover 4
4661 Points ∼2% -12%
CAT S40
4415 Points ∼2% -17%
GFXBench (DX / GLBenchmark) 2.7
1920x1080 T-Rex HD Offscreen C24Z16 (sort by value)
CAT S31
5.6 fps ∼0%
AGM A8
2.8 fps ∼0% -50%
Nomu S30
17 fps ∼1% +204%
Samsung Galaxy XCover 4
6.8 fps ∼0% +21%
CAT S40
5.2 fps ∼0% -7%
T-Rex HD Onscreen C24Z16 (sort by value)
CAT S31
9.8 fps ∼2%
AGM A8
9.5 fps ∼2% -3%
Nomu S30
17 fps ∼4% +73%
Samsung Galaxy XCover 4
11 fps ∼2% +12%
CAT S40
12 fps ∼3% +22%
GFXBench 3.0
off screen Manhattan Offscreen OGL (sort by value)
CAT S31
1.9 fps ∼0%
AGM A8
1.8 fps ∼0% -5%
Nomu S30
7.1 fps ∼1% +274%
Blackview BV8000 Pro
10 fps ∼2% +426%
Samsung Galaxy XCover 4
2.6 fps ∼0% +37%
CAT S40
1.8 fps ∼0% -5%
on screen Manhattan Onscreen OGL (sort by value)
CAT S31
4.3 fps ∼1%
AGM A8
4 fps ∼1% -7%
Nomu S30
7.1 fps ∼2% +65%
Blackview BV8000 Pro
11 fps ∼3% +156%
Samsung Galaxy XCover 4
5.4 fps ∼1% +26%
CAT S40
6.2 fps ∼2% +44%

Legend

 
CAT S31 Qualcomm Snapdragon 210 MSM8909, Qualcomm Adreno 304, 16 GB eMMC Flash
 
AGM A8 Qualcomm Snapdragon 410 MSM8916, Qualcomm Adreno 306, 32 GB eMMC Flash
 
Nomu S30 Mediatek Helio P10 MT6755, ARM Mali-T860 MP2, 64 GB eMMC Flash
 
Blackview BV8000 Pro Mediatek Helio P20 (LP4) MT6757, ARM Mali-T880 MP2, 64 GB eMMC Flash
 
Samsung Galaxy XCover 4 Samsung Exynos 7570 Quad, ARM Mali-T720, 16 GB eMMC Flash
 
CAT S40 Qualcomm Snapdragon 210 MSM8909, Qualcomm Adreno 304, 16 GB eMMC Flash

Depending on the browser benchmark used, the result is mediocre to below average. In daily operation, the low performance is not noticeable though. Elaborately designed websites may take a little longer to load. For most Internet activities, the S31 offers enough performance.

JetStream 1.1 - 1.1 Total Score
Blackview BV8000 Pro (Crome Version 51)
24.288 Points ∼100% +95%
Nomu S30 (Chrome 57)
24.234 Points ∼100% +95%
Samsung Galaxy XCover 4 (Chrome 58)
20.988 Points ∼86% +69%
AGM A8 (Chrome 58.0.3029.83)
16.897 Points ∼70% +36%
CAT S31
12.442 Points ∼51%
Octane V2 - Total Score
Blackview BV8000 Pro (Crome Version 51)
3609 Points ∼100% +80%
Nomu S30 (Chrome 57)
3279 Points ∼91% +63%
Samsung Galaxy XCover 4 (Chrome 58)
3133 Points ∼87% +56%
AGM A8
2733 Points ∼76% +36%
CAT S31
2010 Points ∼56%
Mozilla Kraken 1.1 - Total Score
Nomu S30 (Chrome 57)
23913.5 ms * ∼100% -34%
Blackview BV8000 Pro (Crome Version 51)
23223.7 ms * ∼97% -30%
CAT S31
17827.9 ms * ∼75%
AGM A8 (Chrome 58.0.3029.83)
12247.9 ms * ∼51% +31%
Samsung Galaxy XCover 4 (Chrome 58)
11130 ms * ∼47% +38%
WebXPRT 2015 - Overall Score
Samsung Galaxy XCover 4 (Chrome 58)
61 Points ∼100%

* ... smaller is better

Our reference card Toshiba Exceria Pro SDXC 64 GB UHS-II enables the S31 to achieve average read and write rates. This means our test device can at least be placed near the better comparison devices. The internal memory, on the other hand, is accessed much more slowly. The 16 GB flash memory can be expanded to 128 GB with a memory card and installed apps can be outsourced to it.

CAT S31AGM A8Nomu S30Blackview BV8000 ProSamsung Galaxy XCover 4
AndroBench 3-5
-21%
65%
119%
31%
Sequential Write 256KB SDCard
59.5
20.46 (Toshiba Exceria Pro M401)
-66%
21.52 (Toshiba Exceria Pro M401)
-64%
68.65 (Toshiba Exceria Pro M501)
15%
55.66 (Toshiba Exceria Pro M401)
-6%
Sequential Read 256KB SDCard
81.8
22.01 (Toshiba Exceria Pro M401)
-73%
36.94 (Toshiba Exceria Pro M401)
-55%
79.34 (Toshiba Exceria Pro M501)
-3%
68.97 (Toshiba Exceria Pro M401)
-16%
Random Write 4KB
14.81
3.73
-75%
8.84
-40%
15.05
2%
11.9
-20%
Random Read 4KB
14.28
11.44
-20%
27.99
96%
52.74
269%
21.8
53%
Sequential Write 256KB
62.13
69.47
12%
194.95
214%
177.09
185%
73.6
18%
Sequential Read 256KB
71.06
140.67
98%
241.97
241%
246.42
247%
181.6
156%

Games

Qualcomm's built-in Adreno-304 graphics unit is only suitable for modest games. Therefore, users should limit themselves to older or simple games. The older first-person shooter Dead Trigger runs very smoothly on the S31 and can also be easily handled on the small screen. The touchscreen reacts reliably to inputs. Recent casual games such as South Park: Phone Destroyer also run smoothly and load quickly. In the active game, however, there may be small lags. The outdoor phone is therefore also suitable for the occasional gaming session.

South Park: Phone Destroyer
South Park: Phone Destroyer
Dead Trigger
Dead Trigger

Emissions

Temperature

During idle and in everyday operation, the S31 remains cool. Surface temperatures rarely exceed 30 °C, with the hotspots on the front of the unit. Our test device heats up noticeably under load but does not get hot.

Max. Load
 34.5 °C
94 F
33.9 °C
93 F
31.7 °C
89 F
 
 36.4 °C
98 F
34.9 °C
95 F
31.9 °C
89 F
 
 35.4 °C
96 F
34.9 °C
95 F
31.6 °C
89 F
 
Maximum: 36.4 °C = 98 F
Average: 33.9 °C = 93 F
29.4 °C
85 F
32.2 °C
90 F
30.3 °C
87 F
30.1 °C
86 F
33.5 °C
92 F
31.7 °C
89 F
29.9 °C
86 F
33.9 °C
93 F
32.8 °C
91 F
Maximum: 33.9 °C = 93 F
Average: 31.5 °C = 89 F
Power Supply (max.)  34.2 °C = 94 F | Room Temperature 21.9 °C = 71 F | Voltcraft IR-350
Front
Front
Back
Back

Speakers

A clear, powerful sound is provided by the S31 speaker. The volume is subjectively sufficient to produce audible sounds even in louder environments. According to our measurements, the maximum volume is only moderate. In addition, our test device lacks basses. Since these are relatively flat, there is no abrupt loss of sound. The slightly muffled sound of the loudspeaker also compensates for the missing bass.

dB(A) 0102030405060708090Deep BassMiddle BassHigh BassLower RangeMidsHigher MidsLower HighsMid HighsUpper HighsSuper Highs2025.926.325.9252527253126.529.626.54031.131.631.15032.734.632.76326.728.326.78025.628.325.610026.530.926.512532.823.932.816032.322.432.320037.222.537.225039.824.139.831544.222.844.240047.521.247.550051.819.351.863054.116.554.180060.115.660.1100064.716.364.7125065.21565.2160066.214.866.2200067.214.567.2250066.614.366.6315067.51467.5400067.413.967.4500065.413.965.4630061.813.961.8800060.313.860.31000057.213.857.21250053.613.853.61600053.413.853.4SPL76.928.176.9N35.71.135.7median 57.2CAT S31median 15median 57.2Delta11.24.111.239.638.233.633.131.232.130.832.130.734.3343530.939.428.736.426.247.92651.925.354.82557.223.359.622.362.521.164.820.167.719.568.120.166.219.669.318.8731874.817.877.317.67617.675.517.773.517.873.81871.417.765.417.853.517.848.531.285.31.661.7median 19.5Apple iPhone Xmedian 66.23.29.2hearing rangehide median Pink Noise
CAT S31 audio analysis

(±) | speaker loudness is average but good (76.9 dB)
Bass 100 - 315 Hz
(-) | nearly no bass - on average 21.7% lower than median
(±) | linearity of bass is average (7.8% delta to prev. frequency)
Mids 400 - 2000 Hz
(±) | higher mids - on average 7% higher than median
(+) | mids are linear (6.8% delta to prev. frequency)
Highs 2 - 16 kHz
(±) | higher highs - on average 6.5% higher than median
(+) | highs are linear (4% delta to prev. frequency)
Overall 100 - 16.000 Hz
(±) | linearity of overall sound is average (24.6% difference to median)
Compared to same class
» 44% of all tested devices in this class were better, 11% similar, 44% worse
» The best had a delta of 14%, average was 25%, worst was 44%
Compared to all devices tested
» 68% of all tested devices were better, 7% similar, 25% worse
» The best had a delta of 3%, average was 21%, worst was 53%

Apple iPhone X audio analysis

(+) | speakers can play relatively loud (85.3 dB)
Bass 100 - 315 Hz
(±) | reduced bass - on average 14.9% lower than median
(±) | linearity of bass is average (9.4% delta to prev. frequency)
Mids 400 - 2000 Hz
(+) | balanced mids - only 3.4% away from median
(+) | mids are linear (5.1% delta to prev. frequency)
Highs 2 - 16 kHz
(±) | higher highs - on average 7.3% higher than median
(+) | highs are linear (4.6% delta to prev. frequency)
Overall 100 - 16.000 Hz
(±) | linearity of overall sound is average (18.4% difference to median)
Compared to same class
» 5% of all tested devices in this class were better, 5% similar, 90% worse
» The best had a delta of 14%, average was 25%, worst was 44%
Compared to all devices tested
» 34% of all tested devices were better, 6% similar, 60% worse
» The best had a delta of 3%, average was 21%, worst was 53%

Frequency diagram in comparison (checkboxes above can be turned on/off!)

Energy Management

Power Consumption

In comparison, the S31 is a relatively efficient device. Especially under load, it achieves the lowest consumption rate of all comparable devices. In idle mode, however, the measurement result is only good enough for a medium ranking.

Power Consumption
Off / Standbydarklight 0.21 / 0.33 Watt
Idledarkmidlight 0.73 / 2.21 / 2.25 Watt
Load midlight 2.99 / 4.12 Watt
 color bar
Key: min: dark, med: mid, max: light        Metrahit Energy
CAT S31
4000 mAh
AGM A8
4050 mAh
Nomu S30
5000 mAh
Blackview BV8000 Pro
4180 mAh
Samsung Galaxy XCover 4
2800 mAh
CAT S40
 mAh
Power Consumption
-23%
-27%
-16%
-4%
-24%
Idle Minimum *
0.73
0.86
-18%
0.93
-27%
0.85
-16%
0.56
23%
1.2
-64%
Idle Average *
2.21
1.97
11%
2.31
-5%
1.56
29%
1.57
29%
2
10%
Idle Maximum *
2.25
2.04
9%
2.35
-4%
1.67
26%
1.68
25%
2.1
7%
Load Average *
2.99
4.86
-63%
4.57
-53%
4.37
-46%
4.6
-54%
4.3
-44%
Load Maximum *
4.12
6.43
-56%
6.1
-48%
7.06
-71%
5.92
-44%
5.3
-29%

* ... smaller is better

Battery Life

Our test device delivers superior battery life. Almost 18 hours in a wireless LAN with the display switched on and active browser is a very good performance. None of the comparable devices achieved a similarly high value. The standby time is accordingly longer. In everyday life, the battery lasts for almost a week with moderate use of the device. However, we did not check the 30-day standby time promised by the manufacturer.

If the battery life of the S31 is not enough, you can order a suitable 10,000 mAh powerbank in the Catphone shop for 55 Euros (~$66).

Battery Runtime
NBC WiFi Websurfing Battery Test 1.3
17h 54min
CAT S31
4000 mAh
AGM A8
4050 mAh
Nomu S30
5000 mAh
Blackview BV8000 Pro
4180 mAh
Samsung Galaxy XCover 4
2800 mAh
CAT S40
 mAh
Battery Runtime
WiFi v1.3
1074
654
-39%
832
-23%
688
-36%
668
-38%
611
-43%

Pros

+ Robust case
+ Water- and dust-proof
+ Freely assignable key
+ Operation in gloves possible
+ Excellent battery life
+ Very high brightness

Cons

- Battery not replaceable
- Weak SoC
- Mediocre cameras

Verdict

The Cat S31 was provided by: CAT Phones Germany
The Cat S31 was provided by: CAT Phones Germany

In our tests, the CAT S31 proves to be the device that the manufacturer promises: A rugged smartphone that can cope with almost any environment. The fact that the technical internals are not up to date with the latest developments can be accepted, but potential customers could choose the far cheaper competitor AGM. As a pure smartphone, the S31 is an entry-level device with a stable system and solid performance. Simple apps and browser activities are no problem with the device. If you like, you can even control it in gloves.

The CAT S31 is a solid smartphone whose main task is not to break. It achieves this in any case, but users have to do without demanding applications.

Buying such a robust device is often a gut decision. Certifications and rough, angular designs are offered by all suppliers of such devices. Whether the CAT S31 can really withstand the most extreme conditions can only be seen through an endurance test in the respective application area of its user. The S31 makes a very solid impression on us, but the high price cannot be justified by the performance and the case alone.

CAT S31 - 12/29/2017 v6
Mike Wobker

Chassis
86%
Keyboard
67 / 75 → 90%
Pointing Device
89%
Connectivity
37 / 60 → 62%
Weight
88%
Battery
100%
Display
87%
Games Performance
4 / 63 → 7%
Application Performance
21 / 70 → 31%
Temperature
92%
Noise
100%
Audio
59 / 91 → 65%
Camera
54%
Average
68%
79%
Smartphone - Weighted Average

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> Notebook / Laptop Reviews and News > Reviews > CAT S31 Smartphone Review
Mike Wobker, 2018-01- 3 (Update: 2018-01-23)