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

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

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. 

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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.

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.

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.

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.

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.