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Samsung C34F791/CF791 MONITOR REVIEW

Usage Ratings - Version 1.0
6.9
Mixed Usage
6.9
Office
7.5
Gaming
6.7
Multimedia
6.9
Media Creation
5.4
HDR Gaming
Size : 34"
Resolution : 3440x1440
Refresh Rate : 100 Hz
LCD Type
:
VA
Variable Refresh Rate
:
FreeSync

The Samsung CF791 is a decent ultrawide monitor. It has a VA panel which can produce deep dark scenes which is good for those in a dark room. It also has great gray uniformity, which is good for watching videos or browsing the web. Unfortunately, the image degrades when viewed at an angle, but the curvature of the display helps to mitigate this. The C34F791 also has great motion handling with a fast 100Hz refresh rate.

Test Results
Design 8.0
Picture Quality 6.3
Motion 8.7
Inputs 7.9
Pros
  • Can produce deep dark scenes
  • Colors appear uniform
  • Great motion handling
Cons
  • Image degrades when viewed at an angle
  • Higher input lag than other monitors
  1. Update 1/17/2019: We tested the monitor's compatibility with NVIDIA's new FreeSync driver. See our full investigation into NVIDIA's FreeSync Drivers here.
  2. Update 1/7/2019: The gradient score has been updated, as it was scored incorrectly at the time of the review.
  3. Update 11/6/2018: There was an error with the curve radius scoring which has been fixed. This has not changed the usage scores for this monitor.

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8.0

Design

Curved : Yes
Curve radius : 1500R
Weight (without stand)
:
13.2 lbs (6.0 kg)
Weight (with stand)
:
16.5 lbs (7.5 kg)

The design of the Samsung CF791 is very good. The stand supports it well and the monitor feels sturdy. Due to the stand design, the monitor looks thick when viewed from the side. In general, it has an elegant look and nice cable management that adds to its premium feel. The build quality is good and you should have no problems with it. 

Stand
Width
:
9.7" (24.6 cm)
Depth
:
12.2" (31.0 cm)

The Samsung C34F791 has a round stand that supports the monitor well.

4.7 Ergonomics
Height Adjustment
:
3.9" (9.9 cm)
Switch portrait/landscape : No
Swivel Range : N/A
Tilt Range : -20° to 15°

The tilt range varies along the height adjustment positions:
@ top: 15° to -20°
@ bottom: 2.5° to -30°

The ergonomics of the monitor are inadequate. For a large monitor like this, the provided positioning options are not enough to allow you to place it in a comfortable position.

Back
Wall Mount : VESA 100x100

The back of the monitor is plain. Most of the inputs are housed in a compartment (that comes with a cover) and are pointing downwards so as not to protrude, except the USB ports and the headphones jack.

It is nice that both 100x100 & 200x200 (using the included adapter) VESA wall mounts options are available.

The cable management through the stand is very nice and makes the monitor look clean on the back.

Borders
Borders
:
0.3" (0.8 cm)

The borders are thin and elegant. This is good for those who want to use multiple monitors as they can be placed together without much gap.

Thickness
Thickness (with stand)
:
8.1" (20.6 cm)
Thickness (without stand)
:
4.6" (11.7 cm)

The monitor is quite thick. This is mainly due to its stand and less due to the curvature of the screen, which does mean it has to sit back quite far from a wall. If you VESA mount it, it will not protrude too much given its size.

8.0 Build Quality

The build quality of the Samsung CF791 is great. There are no gaps or loose ends and you should have no issues.

6.3

Picture Quality

The picture quality of the Samsung CF781 is decent. It has a good contrast ratio and great gray uniformity, good color accuracy, and no color bleed. Reflection handling is good but the monitor cannot get very bright to be suitable for very bright rooms. It has poor viewing angles, typical of VA panels, and some banding is visible in the darker shades. 

7.6 Contrast
Native Contrast
:
2527 : 1
Contrast with local dimming
:
N/A

The Samsung CF791 has very good contrast. When placed in a dark room, blacks look deep and this helps the picture quality.

0 Local Dimming
Local Dimming
:
No
Backlight
:
Direct

The Samsung C34F791 does not have a local dimming feature. The video is for reference only.

7.0 SDR Peak Brightness
SDR Real Scene
:
264 cd/m²
SDR Peak 2% Window
:
247 cd/m²
SDR Peak 10% Window
:
246 cd/m²
SDR Peak 25% Window
:
246 cd/m²
SDR Peak 50% Window
:
245 cd/m²
SDR Peak 100% Window
:
244 cd/m²
SDR Sustained 2% Window
:
246 cd/m²
SDR Sustained 10% Window
:
246 cd/m²
SDR Sustained 25% Window
:
245 cd/m²
SDR Sustained 50% Window
:
245 cd/m²
SDR Sustained 100% Window
:
244 cd/m²
SDR ABL
:
0.001

Decent SDR peak brightness for this monitor. It keeps the same level of brightness across the various bright window sizes and this is great. This is fine for most rooms, but may not be bright enough to overcome glare in a bright room.

0 HDR Peak Brightness
HDR Real Scene
:
N/A
HDR Peak 2% Window
:
N/A
HDR Peak 10% Window
:
N/A
HDR Peak 25% Window
:
N/A
HDR Peak 50% Window
:
N/A
HDR Peak 100% Window
:
N/A
HDR Sustained 2% Window
:
N/A
HDR Sustained 10% Window
:
N/A
HDR Sustained 25% Window
:
N/A
HDR Sustained 50% Window
:
N/A
HDR Sustained 100% Window
:
N/A
HDR ABL
:
N/A

HDR is not supported.

4.9 Horizontal Viewing Angle
Color Shift from Left
:
33 °
Color Shift from Right
:
32 °
Brightness from Left
:
45 °
Brightness from Right
:
45 °
Black Level from Left
:
12 °
Black Level from Right
:
11 °
Curve Radius : 1500 R

The horizontal viewing angles are poor. Blacks wash out as soon as you deviate from the center axis and a few degrees later, colors shift and brightness fades. This is mitigated a bit by the curvature of the display, which means that the sides of the screen face towards a central seating position.

4.4 Vertical Viewing Angle
Color Shift from Below
:
26 °
Color Shift from Above
:
26 °
Brightness from Below
:
33 °
Brightness from Above
:
33 °
Black Level from Below
:
5 °
Black Level from Above
:
5 °

The vertical viewing angles are bad. In this case, too, blacks are the first ones to lose accuracy, almost immediately off the center axis. And then followed by a shift in colors and loss of brightness as the viewing angle increases.

8.3 Gray Uniformity
50% Std. Dev.
:
4.408 %
50% DSE
:
0.103 %
5% Std. Dev.
:
1.800 %
5% DSE
:
0.061 %

The gray uniformity of the Samsung CF791 is very good. Very little clouding is visible on our test image and almost no dirty screen effect can be observed when surfing the web.

5.2 Black Uniformity
Native Std. Dev.
:
2.554 %
Std. Dev. w/ L.D.
:
N/A

The black uniformity is disappointing. There is some clouding in the picture in the very dark scenes that some will pick up when seated in a dark room.

7.2 Pre Calibration
Picture Mode
:
Custom
Luminance
:
242 cd/m²
Luminance Settings
:
100
Contrast Setting
:
75
RGB controls
:
Cool1
Color Temperature
:
6346 K
White Balance dE
:
3.46
Color dE
:
3.09
Gamma
:
2.26

The out-of-the-box color accuracy of the Samsung C34F791 is good. The Custom picture mode gave us the best out of the box results. Both the white balance dE and the color dE were above our target of 3, thus some people will pick up gray and color inaccuracies. Color temperature was slightly warm giving the picture a very slight red-yellowish tone. Gamma was slightly above our 2.2 target and shades look slightly brighter.

9.5 Post Calibration
Picture Mode
:
Custom
Luminance
:
99 cd/m²
Luminance Settings
:
23
Contrast Setting
:
75
RGB Controls
:
35-44-50
Color Temperature
:
6432 K
White Balance dE
:
0.63
Color dE
:
0.84
Gamma
:
2.19

The color accuracy after post calibration is excellent. White balance dE and Color dE are well below the threshold of 3, and it is highly unlikely that you will notice any inaccuracies. At the same time, Gamma was measured almost on the target of 2.2 and color temperature remained just slightly warmer than our target, but this is not noticeable.

You can download our ICC profile calibration here.

8.8 SDR Color Gamut
sRGB xy
:
95.6 %
Adobe RGB xy
:
80.8 %

s.RGB Picture Mode: Custom (calibrated)
Adobe RGB Picture Mode: Custom

Excellent coverage of the s.RGB colorspace for the Samsung CF791. On the other hand the coverage of the wider Adobe s.RGB colorspace used by professionals in graphics and printing applications is about 80% covered, which isn't really enough for those editing photos in the Adobe RGB color space.

9.3 SDR Color Volume
sRGB in ICtCp
:
98.5 %
Adobe RGB in ICtCp
:
88.2 %

s.RGB Picture Mode: Custom
Adobe RGB Picture Mode: Custom

Excellent results in our color volume test. The monitor is able to display a wide range of SDR colors across its full range of brightness levels.

0 HDR Color Gamut
Wide Color Gamut
:
No
DCI P3 xy
:
N/A
Rec. 2020 xy
:
N/A

HDR is not supported.

0 HDR Color Volume
DCI-P3 in ICtCp
:
N/A
Rec. 2020 in ICtCp
:
N/A

HDR is not supported.

7.7 Image Retention
IR after 0 min recovery
:
0.11 %
IR after 2 min recovery
:
0.00 %
IR after 4 min recovery
:
0.00 %
IR after 6 min recovery
:
0.00 %
IR after 8 min recovery
:
0.00 %
IR after 10 min recovery
:
0.00 %

The Samsung C34F791 has a good image retention performance. However, some slight signs of image retention are present immediately after the exposure of our test image. This is unlikely to be noticeable in most content.

8.1 Gradient
Color Depth
:
8 Bit

The Samsung CF791 has decent gradient performance. 8-bit banding is present along with some artifacts, especially in dark color shades. This, however, should not be an issue for most usages.

Update 01/07/2019: The gradient score has been updated (7.3 -> 8.1), as it was scored incorrectly at the time of the review.

10 Color Bleed
Pixel row error
:
0.001 %
Pixel column error
:
0.001 %

Perfect color bleed performance as nearby colors are not affected by large uniform shades and this is good for accuracy.

7.5 Reflections

The Samsung CF791 has good reflection handling. The matte finish reduces the reflection intensity by diffusing them on the screen. For most situations this is ok, but in a bright room, reflections might become distracting.

8.7

Motion

The Samsung CF791 has excellent motion handling. It has a very fast response time and the backlight does not flicker when it dims. It supports the FreeSync implementation of the variable refresh rate (VRR) technology to smooth out gameplay on graphics intensive games.

8.9 Motion Blur
80% Response Time
:
4.0 ms
100% Response Time
:
13.7 ms
Best Overdrive Setting
:
Faster

Response Time Standard
Response Time Faster
Response Time Fastest

The Samsung CF791 has an excellent response time. Setting the Response Time overdrive option to Faster provides the shortest response time. The Fastest settings has a better 80% response time, but it adds some considerable overshoot so we recommend the Faster setting.

7.5 Image Flicker
Flicker-free : Yes
PWM Dimming Frequency
:
0 Hz
Black Frame Insertion (BFI)
:
No
BFI Maximum Frequency
:
N/A
BFI Minimum Frequency
:
N/A

The Samsung CF791 dims the backlight without using any PWM flickering. This helps motion be smooth and creates blur. On the other hand, there isn't any black frame insertion option available to add flicker in order to remove blur and make the image look crispier.

8.8 Refresh Rate
Native
:
100 Hz
Factory Overclock
:
N/A
Variable Refresh Rate
:
FreeSync
G-SYNC Compatible
:
Partial
VRR Maximum
:
100 Hz
VRR Minimum
:
< 20 Hz
VRR Maximum With OC
:
N/A
VRR Supported Connectors : DisplayPort, HDMI

The Samsung CF791 has a remarkable refresh rate of 100 Hz, which is better than the common 60 Hz most monitors have but not as good as the 144 Hz of high-end gaming monitors. It also supports FreeSync so as to adjust the screen's refresh rate to the frame rate of a compatible graphics card and prevent tearing.

The monitor's FreeSync Ultimate Engine setting has a range of 100-48 Hz, which is wide enough for FreeSync's Low Framerate Compensation (LFC) feature to extend its effective range to below 20 Hz. Unfortunately the FreeSync Standard Engine setting only has a narrow 100-80 Hz range.

Unfortunately this monitor's FreeSync implementation has some bugs with how it interacts with some GPUs and graphics drivers. On our Radeon RX 580 test PC it was impossible to make FreeSync work properly over DisplayPort, even though it worked fine over HDMI, and worked fine over DisplayPort on our PC with an AMD Ryzen 3 2200G APU. Also the number of support forum threads about CF791 FreeSync issues is greater than for most monitors of similar popularity, with numerous reports of problems with certain Radeon driver versions and other issues (see our recommendations for the best Freesync monitors).

Update 01/15/2019: We have tested the Samsung CF791 with NVIDIA's new FreeSync drivers, on an NVIDIA GTX 1060 6 Gb. Unfortunately, there were a few issues. With the refresh rate set to 100 Hz, there was no signal when launching any Fullscreen games. It worked fine when we set the refresh rate to 60 Hz. It appears that NVIDIA ignores the window's refresh rate though, as the test pattern was then tear-free up to 100 Hz. We retested the CF791 on a Radeon card, and did not have the same issues.

7.9

Inputs

The input lag of this monitor is okay, although most recent monitors like the CJ791 have lower input lag. On the other hand, this is a 34",  21:9 monitor with great resolution that will give you plenty of space and enough detail to work without issues.

7.2 Input Lag
Native Resolution
:
20.7 ms
Non-Native Res @ Native Refresh
:
N/A
Native Resolution @ 60 Hz
:
26.9 ms
Variable Refresh Rate
:
23.6 ms
10 bit HDR
:
N/A
Black Frame Insertion (BFI)
:
N/A

Variable Refresh Rate tested over HDMI, all others tested over DisplayPort.

The input lag is worse than most monitors.

No non-native resolution is able to run at 100 Hz without using a custom resolution, though nearly all can run at 60 Hz. This isn't usually an issue though because most graphics cards upscale non-native resolutions by default.

The Game mode did not reduce input lag significantly as it was only 0.1 ms shorter with this setting enabled, so we recommend leaving the Game mode disabled for the better picture quality.

The Variable Refresh Rate (VRR) input lag was measured using the HDMI port, because our test PC had trouble with sending FreeSync over DisplayPort with this monitor; see the Refresh Rate box for more detail. We expect the DisplayPort to have the same VRR input lag, because with FreeSync disabled the input lag was the same (20.7 ms via DP, 21.7 ms via HDMI).

8.8 Resolution and Size
Native Resolution : 3440 x 1440
Aspect Ratio : 21:9
Megapixels : 5.0 MP
Pixel Density : 110 PPI
Screen Diagonal : 34.0 inches
Screen Area : 411 sq inches

The Samsung C34F791 is a large 34-inch wide aspect ratio monitor. It has a great resolution that provides you with enough detail to do your work or gameplay.

Inputs

All the monitor's inputs are on the back.

Total Inputs
DisplayPort : 1 (DP 1.2)
Mini DisplayPort : No
HDMI : 2 (HDMI 2.0)
DVI : No
VGA : No
DisplayPort Out : No
USB : 2 (USB 3.0)
USB C : No
Analog Audio Out 3.5mm : 1
Microphone In 3.5mm : No
Digital Optical Audio Out : No
Analog Audio Out RCA : No
Power Supply : External Brick

The monitor's full 3440x1440x100Hz native resolution is supported over both DisplayPort and HDMI, which is great.

During testing we encountered some bugs with the monitor's HDMI ports. When changing between the monitor's HDMI 1.4 and HDMI 2.0 modes, sometimes the increased bandwidth of HDMI 2.0 wasn't detected by our PC until after the resolution was changed once. Also sometimes our PC became stuck at 640x480 or 1080p resolution when the HDMI mode was changed, though after a factory reset this issue never recurred.

Features

The Samsung CF791 On-Screen Display (OSD) is easy to navigate due to a small joystick on the back of the monitor. The OSD has all the standard features of a monitor such as color settings and adjustable overdrive, etc. The monitor has internal speakers and this is a helpful feature.  

Additional Features
Speakers
:
Yes
HDR10 : No
Multiple input display
:
PIP + PBP

The monitor is equipped with 2 internal speakers but does not support HDR.

Note: During general usage we noticed a bug with one of our PCs: when the PC made the monitor go to sleep it consistently made the PC crash (Blue Screen Of Death, BSOD). We didn't notice this problem on other PCs though.

On-Screen Display (OSD)

The on-screen display is easy to navigate using the small joystick on the back of the monitor.

Controls

All of the OSD is accessed by using a joystick at the back of the monitor. This can be inconvenient for people who sit farther away from the monitor. The joystick works well and the menus are easy to navigate.

In The Box

  • Manual and drivers
  • Power cable
  • HDMI cable
  • DisplayPort cable
  • USB cable
  • Mini DisplayPort to DisplayPort adapter

Differences between Sizes and Variants

The CF791 we bought is the 34" model (Samsung LC34F791WQNXZA).

Model Alternative Name Size Refresh rate Resolution
CF791 C34F791 34" 100Hz 3440x1440

If someone's CF791 doesn't correspond to our review, let us know and we will update the review. Note that some tests such as the gray uniformity may vary between individual units.

Compared to other Monitors

Left: LG 34UC79G-B. Middle: Samsung CF791. Right: Asus PG348Q
Unlike our other photographs, this picture wasn't taken under a controlled environment, so do not draw conclusions from it.

The Samsung CF791 is a decent, large screen ultrawide monitor. See our recommendations for the best curved gaming monitors, the best gaming monitors for Xbox One X and the best ultrawide gaming monitors.

Samsung C34J791/CJ791
SEE PRICE
Amazon.com

The Samsung CJ791 is better than the Samsung CF791. The two monitors have very similar picture quality. The Samsung CJ791, however, has a much lower input lag that makes it more responsive to your actions, and this is great regardless if you're a gamer or not. It also has Thunderbolt 3 support.

Dell U3417W
SEE PRICE
Amazon.com

If you've got a large room with wide seating, then the Dell U3417W is a better choice, but if you're interested in gaming in a dark room while sitting directly in front, then the Samsung CF791 is better. The Dell U3417W has an IPS panel, giving you better viewing angles, whereas the CF791 has a slightly better refresh rate and a slightly faster response time resulting in clearer motion.

LG 34UC79G-B
SEE PRICE
Amazon.com

The LG 34UC79G-B is a better monitor than the Samsung CF791 for almost every use, unless you'll be using it in a dark room. The Samsung CF791 has better resolution giving you more details on the screen, but the LG34UC79G has better viewing angles and you'll enjoy gaming more as it has significantly better input lag and marginally better image flicker to clear blur.

Samsung CHG70
SEE PRICE
Amazon.com

The Samsung CHG70 is much better than the Samsung CF791. The CHG70 has much lower input lag, supports HDR, and is equipped with local dimming to make blacks even deeper. You can position it according to your liking and you'll enjoy it in every use. The CF791, on the other hand, is larger, giving you more screen area and more resolution to work with.

LG 34WK95U-W
SEE PRICE
Amazon.com

The two monitors are different types. For most people, the IPS panel LG 34WK95U is better than the VA panel Samsung CF791. The LG supports HDR, has better viewing angles, and has a lower input lag. On the other hand, the Samsung CF791 has better blacks and will perform better in a dark room.

ASUS ROG Swift PG279Q
SEE PRICE
Amazon.com

The ASUS ROG PG279Q is a much better monitor than the Samsung CF791. If you play a lot of games, the ASUS has significantly better input lag, slightly better motion blur and supports G-SYNC to smooth out tearing. Also, the ASUS has better viewing angles, which is great if you wish to use it at the office.

LG 32GK850G-B
SEE PRICE
Amazon.com

The LG 32GK850G is better than the Samsung CF791. The LG 32GK850G has a faster pixel response time, and thus the blur trail in fast action content is smaller. The LG 32GK850G has a faster refresh rate and better input lag, and this is great if you play games. The LG 32GK850G also has better ergonomics that make it easy to place comfortably. The Samsung CF791, on the other hand, supports 4k resolution, is 2 inches larger, and has a curve.

Dell D3218HN
SEE PRICE
Amazon.com

The Samsung CF791 is somewhat better than the Dell D3218HN. The Dell has better viewing angles and is more suitable for collaborative work whereas the Samsung is larger and has a much better resolution that allows you to multitask better. The Dell D3218HN has lower input lag if you play casual video games, but the Samsung has a faster pixel response time that leaves a shorter motion blur, and faster refresh rate with FreeSync support to eliminate tearing.

BenQ EW3270U
SEE PRICE
Amazon.com

The BenQ EW3270U is significantly better than the Samsung CF791. The BenQ EW3270U has better resolution, can display more detail on its screen, and supports HDR content. The EW3270U also has lower input lag and more uniform blacks. The Samsung, on the other hand, has a slightly faster pixel response time that leaves a smaller motion blur, and much better ergonomics to help you position it to your liking.

Acer Predator XB271HU
SEE PRICE
Amazon.com

If you want to work on the same monitor side-by-side with your colleagues at the office, then the Acer Predator XB271HU is a better choice than the Samsung CF791 as it has better viewing angles. The Acer is also better for gaming as it has better input lag, better image flicker to clear blur, and you can easily position it to match your liking. On the other hand, the Samsung CF791 is a larger monitor with higher resolution, giving you more area and more detail to work with.

+ Show more
6.9 Mixed Usage

This is a decent monitor for mixed usage. It has a mediocre picture quality that can display nice dark scenes but the image degrades at an angle. It has great motion handling and excellent color accuracy for professionals.

6.9 Office

This is a decent monitor for office use. Its large screen and excellent resolution give you enough room and detail to work. Unfortunately, the image degrades at an angle and the poor ergonomics will not allow you to easily work side-by-side with a colleague.

7.5 Gaming

The Samsung C34F791 is a good monitor for gaming. It has an ok input lag, fast response time for a smooth image, and the FreeSync implementation of the variable refresh rate technology to prevent tearing. The large size and the excellent resolution of the monitor, give you more screen area and more detail to immerse yourself in your favorite game.

6.7 Multimedia

It is an ordinary monitor for multimedia usage. Its large size and excellent resolution, along with its good reflection handling are its main advantages. On the other hand, the poor viewing angles and the bad ergonomics make it difficult to position it in a comfortable position to enjoy the best picture quality.

6.9 Media Creation

The Samsung C34F791 is decent monitor for media creation. Due to its size and resolution professionals will find it very comfortable for working. However, the coverage of the Adobe RBG color space might not be enough for those who will be using it for publishing or printing applications.

5.4 HDR Gaming

Unfortunately, the Samsung CF791 does not support HDR like the Samsung CHG70.

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