AOC Q27G4ZR Review: A Fast QHD 240 Hz Gaming Monitor

The market for QHD gaming monitors has never been so competitive. Several manufacturers now manage to offer this kind of specification as Full HD screens gradually give way.

The AOC Q27G4ZR carries a 27-inch IPS panel with a definition of 2560 x 1440 pixels and a refresh rate of 240 Hz. That combination is a good compromise for PC players today: the definition is fine enough for a detailed image, while the high frequency guarantees excellent fluidity in competitive titles.

It lines up directly against references such as the Asus TUF VG27AQML5A, the ROG Strix XG27ACS and the Iiyama G-Master GB2791QSU-B1.

AOC keeps the now familiar design of its gaming range here. There is a black body lifted by a few red touches at the rear, all made in fairly simple plastic. The materials do not exude high-end quality, but the assembly is serious and the screen does not give any impression of fragility.

A pleasant surprise is that the stand is fully adjustable. It allows the height to be set, the screen to be tilted, swivelled laterally and even rotated into portrait mode, a versatility that is not always present.

Connections stick to the essentials, with two HDMI ports, one DisplayPort and a mini-jack headphone output. There is no USB port at all: no USB-A, no USB-C, and therefore no charging function and no hub. Not every user will necessarily need those connectors.

AOC also fits two speakers. As is often the case on this type of product, they will mainly serve as a stopgap for watching a few videos or for occasional office use, while players will obviously prefer a headset or a dedicated audio system.

Navigating the menus is handled by buttons placed under the screen. The absence of a joystick is regrettable, since that solution proves considerably more convenient day to day. The menu tree stays easy to grasp, but moving around it with separate keys can quickly become tedious.

AOC has visibly paid particular attention to calibrating this screen. An average delta E of only 1.7 was measured in SDR, an excellent figure for a gaming monitor. Every colour stays below the threshold of 3, and most below 2, which is the value at which drift becomes visible to the naked eye.

Average gamma comes to exactly 2.2, the expected reference. It cannot be said that the monitor reproduces grey levels faithfully, however, because dark areas prove far too light. The average colour temperature, measured at 6180 K, is for its part slightly below the 6500 K target. The image therefore appears a little warmer than the standard, but the gap is small and will not trouble most users.

As is often the case with an IPS panel, contrast remains limited. A ratio of 1023:1 was recorded, a result in line with what this technology usually offers, but low all the same. Blacks appear less deep than on a VA panel and are obviously a long way from OLED performance. In exchange, viewing angles are excellent and the image keeps its quality even when you are not sitting perfectly square to the screen.

The panel has a matte treatment, so reflections are limited. Reflectance was measured at 20.2%, a value close to that observed on most current monitors. Reflections are diffused correctly, even if the best screens on the market manage to drop below 15%, including in a bright room.

The Q27G4ZR is HDR10 compatible but supports neither HDR10+ nor Dolby Vision. EOTF curve tracking proves fairly poor and mirrors what was observed with gamma: the screen is brighter than it ought to be. The whole thing also lacks precision in the highlights.

A peak brightness of 412 cd/m² was measured on a 10% window. The screen therefore reaches the performance expected of an HDR400-certified monitor, but that remains fairly modest for a genuinely striking presentation. It was in fact slightly brighter in SDR, climbing to 480 cd/m². Outside Mini-LED, few screens do meaningfully better today.

HDR colorimetry is the main weakness of this monitor. An average delta E of 9.6 was recorded, which translates into very marked drift, so colours lose their accuracy once HDR is enabled.

Colour space coverage is nonetheless satisfactory, at 100% of Rec.709, 94.8% of DCI-P3 and 71.3% of Rec.2020.

This is obviously the ground on which the AOC Q27G4ZR gives its best. With a maximum frequency of 240 Hz it suits enthusiasts of competitive first-person shooters such as Counter-Strike 2, Valorant, Apex Legends, Call of Duty and Battlefield. Such a frequency demands a relatively muscular PC to be exploited fully in QHD, but it guarantees remarkable fluidity.

Input lag was measured at only 8.7 ms in 1080p at 60 Hz, and 4.4 ms at 120 Hz. In practice that display lag is imperceptible: actions performed with a mouse or a controller are reflected on screen immediately.

Persistence of 10 ms is correct for an IPS panel, without equalling the best models on the market. A slight ghosting effect can therefore be observed in certain situations, notably during very fast movement, an area where OLED remains the reigning technology.

The screen is compatible with Adaptive Sync to avoid tearing in games, although it does not carry official FreeSync or G-Sync certification.

With brightness set to 150 cd/m², the Q27G4ZR draws only 15.9 W on the test pattern used. Related to its display area, that value corresponds to 79.1 W/m².

It is therefore among the most frugal gaming monitors in its category, a result that is all the more welcome because it sacrifices neither brightness nor refresh rate.

Against the Iiyama G-Master GB2791QSU-B1, its main rival in this bracket, the AOC benefits from better calibration, but the Iiyama keeps the advantage with a 320 Hz refresh rate and far richer connectivity thanks to its USB-C and USB-A ports.

The Asus TUF VG27AQML5A climbs to 300 Hz and enjoys exemplary colorimetry. The ROG Strix XG27ACS, finally, remains an excellent all-rounder thanks to its more careful finish and irreproachable ergonomics; its refresh rate, limited to 180 Hz, makes it less interesting for competitive players.