AOC CU34G2X Curved Gaming Monitor Review: Speed, Immersion and HDR

The speed you need, but HDR’s lacking.

AOC CU34G2X Curved Gaming Monitor
(Image: © Shutterstock, AOC)

Tom's Hardware Verdict

The AOC CU34G2X isn’t the brightest monitor out there, but its high native contrast and super-accurate color deliver an excellent image. With 144 Hz and FreeSync and G-Sync (unofficially) with HDR, game performance is among the best we’ve seen at its current price point. It’s definitely worth serious consideration for ultra-wide seekers.


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    Blur-reduction up to 144 Hz

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    Extended color

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    Accurate out of the box


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    Low light output

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    DCI-P3 color gamut volume slightly smaller than similar monitors

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    HDR doesn’t look much better than SDR

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HDR support is becoming increasingly important to having the best gaming monitor. We all agree that AMD FreeSync or Nvidia G-Sync is a must regardless of a display’s max refresh rate. But more games are appearing that take advantage of HDR and the extended color of the DCI-P3 gamut. To fully realize the creator’s intent, one must consider adding these features to their shopping list.

AOC has produced many high-performance gaming screens, and today we’re looking at one with HDR and FreeSync, the AOC CU34G2X. It’s an ultra-wide curved VA panel, 34-inches diagonal, 3440x1440 resolution and the promise of high performance, thanks to a 144 Hz refresh rate and a claimed 1ms response time. 

 AOC CU34G2X Specs

Swipe to scroll horizontally
Panel Type & BacklightVA / W-LED, edge array
Screen Size & Aspect Ratio34 inches / 21:9
Curve radius1500mm
Max Resolution & Refresh3440x1440 @ 144 Hz
FreeSync48-144 Hz
Native Color Depth / Gamut8-bit / DCI-P3, HDR10 
Response Time (GTG)1ms
Brightness300 nits
Video Inputs2x DisplayPort 1.2; 2x HDMI 2.0
Audio3.5mm headphone output
USB 3.21x up, 4x down
Power Consumption47w, brightness @ 200 nits
Panel Dimensions31.8 x 15.6-20.6 x 10.5 inches
WxHxD w/base(808 x 396-523 x 267mm)
Panel Thickness4 inches (102mm)
Bezel WidthTop/sides: 0.3 inch (8mm), Bottom: 0.9 inch (24mm)
Weight17.9 pounds (8.1kg)
Warranty3 years

AOC starts with a 1500mm radius curved panel. It features a claimed 300 nits of brightness, and although AOC’s product page doesn’t advertise the CU34G2X as an HDR monitor, it supports HDR with HDR10 and an extended color gamut. FreeSync is the adaptive refresh tech of choice, but we confirmed in our tests that the CU34G2X will also run G-Sync (follow our instructions on how to run G-Sync on a FreeSync monitor), and both flavors worked with HDR. Color depth is 8-bits, so 10-bit HDR signals are compressed, but this is common practice in all but the most expensive 10-bit native monitors.

It also features the latest connectivity with DisplayPort 1.4 and HDMI 2.0 (see our DisplayPort vs. HDMI analysis for comparison), and the USB ports are version 3.2. For purists who would rather do without Adaptive-Sync, there is a blur-reduction option similar to G-Sync’s ULMB called MBR, and it works at speeds up to the max refresh of 144 Hz. The lower limit for FreeSync is 48Hz. You won’t need the best graphics card or even a high-end one to drive it, but you will want enough power to keep the action above 48 frames per second (fps). 

The CU34G2X is a bit pricier than 27-inch 16:9 1440p screens with similar feature sets but that extra screen width and its tight 1500R curvature should deliver a more immersive experience in first-person games and flight simulators. 

Unpacking and Accessories

AOC provides a quality stand and solid base for the CU34G2X that attaches to the panel without tools. The carton also includes DisplayPort, HDMI and USB cables. An IEC power cord provides the necessary electrons for a panel that draws 47 watts when the backlight is set to 200 nits. 

One thing we rarely see bundled with gaming monitors is a calibration data sheet. AOC provides color error information of a Delta E (dE) of less than 3 and a screen uniformity measurement as well. Our tests agreed with the data; this monitor is very accurate out of the box. 

Product 360

The CU34G2X has a thin bezel with a flush-mounted anti-glare layer that appears frameless when the power is off. The image shows an 8mm border with a wider trim strip across the bottom. The front layer has almost no air gap, which eliminates any grain from the picture and renders it very sharply. Uniformity is excellent with no bleed, glow or hotspots visible in our sample.

Styling is clearly gaming oriented, but AOC has left out RGB lighting. The red trim seems to glow in the photos, but that is simply its reflective surface in action. The only LED lighting is a miniscule power indicator that glows white in operation and orange in standby. The red trim extends around back with two large chevrons that accent the panel and a vertical stripe on the upright.

The stand is solid and features a 5-inch height adjustment with 30-degree  swivel to either side and 21.5-degree back tilt. Movements are firm and sure with no play. If you’d rather use an aftermarket mount solution, the stand unsnaps to reveal a 100mm VESA bolt pattern. You’ll have to supply your own fasteners though.

The control buttons are in the expected place underneath on the right, but AOC chose to make them very small and recessed. Though they click firmly, they are hard to operate by feel. On a positive note, they don’t stick out visibly, but we really wish they were larger -- or better yet, replaced with a joystick.

There aren’t any side-mounted USB ports, but you’ll find one upstream and four downstream v3.2 connections on the input panel. You also get two each of DisplayPort 1.4 and HDMI 2.0. FreeSync with HDR will work through any video input but to run G-Sync (unofficially) requires DisplayPort as usual. All support the CU34G2X’s full native resolution at 144 Hz.

OSD Features

The OSD is AOC’s usual strip across the bottom of the screen. It’s divided into seven sections and includes everything needed for calibration and gaming. You’ll have little need for the color controls though. The CU34G2X is very accurate by default.

(Image credit: Tom's Hardware)

The Luminance menu has brightness and contrast sliders along with eight picture modes (Eco Modes) and three gamma presets. The HDR Mode options are only available with HDR signals, meaning there is no emulation here for SDR content. We settled on DisplayHDR as the best choice for all HDR games and video.


(Image credit: Tom's Hardware)

You can calibrate the CU34G2X by selecting the User color temp, but in our tests, we couldn’t improve upon the monitor’s default grayscale or gamma tracking. Among the color temp options is an sRGB mode that’s accurate and the only way to reduce the monitor’s gamut from its native DCI-P3. The brightness slider is still available, so this mode is useful to those wishing to view their SDR content in the correct color space.

(Image credit: Tom's Hardware)

The Game Setup menu has all the necessary features to tweak gameplay, including an Adaptive-Sync toggle, blur-reduction (MBR), a frame rate counter and overdrive. For overdrive, any setting above Weak produced ghosting, but at frame rates above 80 fps, there wasn’t any blur to speak of anyway. Additionally, you must turn off Adaptive-Sync to access the MBR feature, which has 20 levels of control. Each one gets darker as blur reduces. Also here is a slider to adjust color saturation and a low blue mode for reading.

Setup and Calibration

The CU34G2X’s Standard picture mode with Warm color temp and Gamma 1 is the default and best setting. Our tests showed it to be very accurate, and we were unable to improve upon the initial numbers in the User color temp mode. If you want a darker gamma, Gamma 3 looked good too, thanks to the VA panel’s high contrast. The backlight doesn’t peak at a high level and will go down to a dim 38 nits if you zero the brightness slider. 

For HDR content, we suggest the DisplayHDR mode for the best contrast and color fidelity. Here are the brightness settings for commonly used output levels in SDR mode. When an HDR signal is detected, the backlight is locked to its maximum setting.

Swipe to scroll horizontally
Picture ModeStandard
Brightness 200 nits70
Brightness 120 nits26
Brightness 100 nits20
Brightness 80 nits14
Brightness 50 nits4
Minimum brightness38 nits
HDR ModeDisplayHDR

Gaming and Hands-on

Without a doubt, the CU34G2X excelled when playing SDR games like Tomb Raider. With its extra color and contrast, details like rock faces and metallic textures just popped off the screen. You can tell AOC engineered the color well here because reds never looked oversaturated, and the all-important flesh tones appeared perfectly natural. Highlights were nice and bright with deep shadows that retained their detail. We didn’t have to employ the shadow control option to easily see everything in the game’s darkest places.

With FreeSync on and Tomb Raider at medium settings, frame rates clocked in at 65-70 fps with an AMD Radeon R9 285-powered system. Even though the AOC CU34G2X isn’t officially G-Sync Compatible, we ran G-Sync on it with an Nvidia GeForce GTX 1080 Ti and hit 120-130 fps with details maxed out. We also tried the various overdrive settings and settled on Weak as the best option. It added a bit of motion resolution without ghosting.

Switching Windows to HDR proved interesting. The CU34G2X isn’t terribly bright, so we maxed the control panel luminance slider, then loaded up Call of Duty: WWII. A few tweaks of the in-game controls produced decent highlights and deep blacks with good shadow detail. This title is particularly well-designed to deliver a great image on any monitor when you use the provided adjustments.

Frame rates settled at around 50 fps with FreeSync and a Radeon R9 285 and 100 fps with G-Sync and a 1080 Ti. Call of Duty: WWII demands a bit more processing power, and HDR slowed things down a little. In either case, the picture looked fantastic. We spent some time exploring a Paris office building with rooms that were either brightly lit or cast in dark lamp shadows. The extra color helped bring murky details out of the fog, while highlights shined out. We wished for a bit more brightness, but once our eyes adjusted, the view was very engaging. That’s the magic of a tightly curved monitor like the CU34G2X. Its 1500mm radius wrapped the image to the edge of our peripheral vision when sitting about 3 feet away. Pixel density was never an issue with 109ppi available.

Like all curved monitors with good video processing and a fast refresh rate, the CU34G2X provides a game experience beyond what any 16:9 flat panel can deliver. While we’ve been more than satisfied with flat screens of 32 inches and larger, the ultra-wide is still our favorite gaming tool.

Christian Eberle
Contributing Editor

Christian Eberle is a Contributing Editor for Tom's Hardware US. He's a veteran reviewer of A/V equipment, specializing in monitors. Christian began his obsession with tech when he built his first PC in 1991, a 286 running DOS 3.0 at a blazing 12MHz. In 2006, he undertook training from the Imaging Science Foundation in video calibration and testing and thus started a passion for precise imaging that persists to this day. He is also a professional musician with a degree from the New England Conservatory as a classical bassoonist which he used to good effect as a performer with the West Point Army Band from 1987 to 2013. He enjoys watching movies and listening to high-end audio in his custom-built home theater and can be seen riding trails near his home on a race-ready ICE VTX recumbent trike. Christian enjoys the endless summer in Florida where he lives with his wife and Chihuahua and plays with orchestras around the state.

  • DookieDraws
    I thought for sure I had already read a review on Tom's for this monitor, not long ago. Hmmmmmmmmm. I've also been looking at this monitor very hard lately. But there are others I'm looking at as well. This seems to be a well like monitor, from what I have read around the web.
  • colson79
    Some of the quotes make me laugh. Such as

    "While the best VR headsets still provide a greater sense of sensory deprivation, a curved 21:9 screen manages to capture much of that feeling without a bulky apparatus on your head"

    I have a widescreen monitor and a VR headset. While I love widescreen monitors they don't even come close to the impressiveness of VR. Not even a little bit.
  • MaCk0y
    It seems all the stock for this monitor went to reviewers. I bought this monitor in February and I think I won't get it before next year.
  • cchant00
    did I miss it or were the recommended settings not listed?
  • MaCk0y
    Monitor arrived. :)
  • Meerov84
    Admin said:
    The AOC CU34G2X combines a 34-inch 21:9 curved VA panel with 144Hz, Adaptive-Sync and HDR. It promises high performance for gamers seeking the immersion of an ultra-wide display.

    AOC CU34G2X Curved Gaming Monitor Review: Speed, Immersion and HDR : Read more
    I got this monitor and it is good, however I notice the slower pixel response and some ghosting, do you recommend I get the VIOTEK GNV34DBE instead? If the Viotek has a better and faste r panel I can live with the nonadjustable stand until I get a monitor arm. Thank you