Acer Predator X27U bmiipruzx  Monitor Review

The Acer X27U has a stylish design with an all-black plastic body and a silver tripod stand. It has a thin panel, with a thicker section on the back that houses the internal components, similar to other OLED monitors.

The build quality is excellent. The plastic materials feel good and well-made, and there aren't any obvious issues. The stand supports the screen well and doesn't wobble much.

The Acer Predator X27U has incredible ergonomics. You can adjust it in many different ways, making it easy to place in an ideal viewing position, and adjusting the screen on the stand feels nice. At the stand's minimum height, the top of the screen is 16.9" (42.8 cm) from the desk. The inputs are all down-facing, and because they're set into the back housing, they can be difficult to access with the stand on. The back of the stand also has a small clip that you can use for cable management.

The stand has wide-set feet, so it takes up a lot of space, but there's enough space to place your keyboard and mouse.

There's a single joystick underneath the center of the monitor to control the on-screen display.

• DisplayPort cable
• HDMI cable
• USB-C cable
• USB-B to USB-A cable
• Power supply and cable
• User documentation, including calibration report

The Acer Predator X27U has a near-infinite contrast ratio that makes it display perfect blacks next to bright highlights.

OLED panels like this one don't have a backlight, so they don't require a local dimming feature. However, with a near-infinite contrast ratio, there isn't any blooming around bright objects, and it's the equivalent of a perfect local dimming feature. We still film these videos on the monitor so you can see how the screen performs and compare it with a monitor that has local dimming.

The SDR brightness is okay. It gets brighter with some small highlights than other OLEDs, but its overall brightness is still limited, and it isn't bright enough to fight glare in a well-lit room. If you're looking for an OLED monitor that gets brighter, look at the LG 27GS95QE-B. The Acer's Automatic Brightness Limiter (ABL) isn't aggressive, especially for an OLED, but it's still strong enough that you can see the brightness change when maximizing and minimizing windows. If this bothers you, there's a Constant Brightness setting that limits the brightness to minimize the effect of ABL, and you can see the results with it on below:

• Real Scene 176 cd/m²
• Peak 2% Window 194 cd/m²
• Peak 10% Window 203 cd/m²
• Peak 25% Window 207 cd/m²
• Peak 50% Window 208 cd/m²
• Peak 100% Window 208 cd/m²
• Sustained 2% Window 193 cd/m²
• Sustained 10% Window 202 cd/m²
• Sustained 25% Window 205 cd/m²
• Sustained 50% Window 206 cd/m²
• Sustained 100% Window 207 cd/m²
• ABL 0.005
• Minimum Brightness 14 cd/m²

Each set of these results are from after calibration in the 'User' Color Mode with the Brightness at its max of '100'.

The Acer X27U has okay peak brightness, which is similar to the Corsair XENEON 27QHD240 but isn't as bright as the ASUS ROG Swift OLED PG27AQDM. While small highlights get brighter than the rest of the image, it isn't bright enough for a vivid HDR experience. The EOTF is a bit darker than the target PQ curve, and because there's a slow roll-off, highlights don't get the brightest they could. These results are with HDR set to 'Auto', Color Space to 'HDR', and the Brightness locked to its max.

Like in SDR, the Constant Brightness setting limits the ABL by dimming the entire screen, as you can see with the results below.

• Real Scene 167 cd/m²
• Peak 2% Window 368 cd/m²
• Peak 10% Window 329 cd/m²
• Peak 25% Window 213 cd/m²
• Peak 50% Window 212 cd/m²
• Peak 100% Window 212 cd/m²
• Sustained 2% Window 364 cd/m²
• Sustained 10% Window 324 cd/m²
• Sustained 25% Window 212 cd/m²
• Sustained 50% Window 210 cd/m²
• Sustained 100% Window 211 cd/m²
• ABL 0.042

The horizontal viewing angle is outstanding. While it technically isn't perfect, you won't notice any issues when viewing from the sides.

The Acer Predator X27U has a remarkable vertical viewing angle, and you won't notice any problems when standing up and looking down at the monitor.

The gray uniformity with medium and light grays is excellent. There aren't any noticeable issues, and there's minimal dirty screen effect in the center, which is great. That said, the uniformity is worse with darker grays. You can see thin vertical lines, and while this is normal for most OLEDs, it's worse on this monitor as you can see here and here. This is most noticeable in full-screen content with dark grays, like gaming menus, but you don't see it with pure blacks.

The Acer X27U has perfect black uniformity thanks to its OLED panel. There isn't any blooming around bright objects on dark backgrounds.

The accuracy before calibration is very good in the sRGB mode. Setting Color Space to 'sRGB' limits colors well enough to the sRGB color space, but reds and greens are still slightly oversaturated. The white balance is also slightly off, and the color temperature is on the warm side, resulting in a slightly red tint. Gamma doesn't follow the target sRGB curve perfectly either, as most scenes are too dark. The sRGB mode locks some picture settings and dims the screen, so if you want to customize those settings and get higher brightness, you need to use another mode that has more oversaturated colors, as you can see here.

The accuracy after calibration is fantastic. It fixes most issues, and you get a brighter image than in the sRGB mode.

The SDR color gamut is fantastic. It has perfect coverage of the common sRGB color space, and it has great coverage in the wider Adobe RGB color space. However, it oversaturates most colors in Adobe RGB, except for blues and greens, which are undersaturated.

The SDR color volume is remarkable. It displays bright and dark colors without any issues.

The HDR color gamut is excellent. It displays a wide range of colors in the commonly-used DCI-P3 color space, but it doesn't tone map well, as most colors are off. These results are with a 75% stimulus, but it tone maps better with a 50% stimulus, as you can see here, meaning brighter colors are inaccurate. That said, that's the case with most monitors anyway. Additionally, it has more limited coverage of the wider Rec. 2020 color space and has the same tone mapping issues. If you're looking for a monitor with an even better HDR color gamut, check out the Dell Alienware AW2725DF.

This monitor has an HDR setting that you can set to 'Off' or 'Auto.' However, the 'Auto' setting isn't a true automatic setting because it stays on even when you disable HDR from your source. Colors are inaccurate in this situation as it tries to emulate an HDR signal, so you need to change the Color Mode to something other than 'HDR' to get an accurate image in SDR and change it back when you enable HDR again

The Acer X27U has an okay HDR color volume. It's mainly limited by its low peak brightness, as it can't display bright and vivid colors like QD-OLED monitors. If you want a monitor with much better HDR color volume, check out the MSI MPG 271QRX QD-OLED.

The reflection handling is fantastic. It has an aggressive matte screen coating that reduces glare from strong light sources well, but it still struggles in bright rooms because of its low peak brightness.

The Acer Predator X27U has alright text clarity. Computer programs don't render text well with its RWBG subpixel layout, causing color fringing around text, as you can see with ClearType enabled (top photo). The same issue occurs even in Windows 11 with ClearType on and with ClearType off. The matte screen coating also negatively impacts the text clarity, as text is hazier than on monitors with a less aggressive screen finish.

Due to its RWBG subpixel layout, all four subpixels are never on at the same time. You can see more examples of the pixels in the LG 27GR95QE-B review, which uses the same panel.

The gradient handling is fantastic, as you won't see any banding in scenes with shades of similar colors, like a sunset.

As the Acer Predator X27U is limited to HDMI 2.0 bandwidth, you can only reach its max refresh rate over a DisplayPort connection. With 10-bit signals over DP, you need a graphics card that supports Display Stream Compression (DSC), which any NVIDIA 16 Series or AMD RX 5000 Series and newer graphics card supports.

The Acer X27U supports FreeSync and G-SYNC over a wide refresh rate range, and both work over DisplayPort. However, only FreeSync works over HDMI, and up to a max of 144Hz. Like some other OLEDs, there's some flicker in dark scenes with VRR enabled, as you can see here. It only occurs with certain content, but it's better to disable VRR if it distracts you.

The Acer Predator X27U has a near-instantaneous response time at its max refresh rate, resulting in minimal motion blur. However, because of the sample-and-hold method on OLEDs, there's still persistence blur.

The response time at 120Hz is outstanding. It has a near-instantaneous response time, so there's minimal motion blur with fast-moving objects.

The response time at 60Hz is remarkable. While there's a bit more overshoot with dark transitions, it's still minimal and not enough to be noticeable.

The Acer Predator X27U doesn't have an optional black frame insertion feature to reduce persistence blur.

This monitor technically isn't flicker-free because there's a slight dip in brightness that corresponds to the 240Hz refresh rate. However, it isn't the same as pulse width modulation because it isn't a full screen on and off, and you won't notice this flicker.

The Acer X27U has low input lag for a responsive feel at its max refresh rate. However, the input lag increases at lower refresh rates, and while it isn't high enough to be noticeable for desktop use, it's disappointing for competitive gaming.

As the monitor is limited to HDMI 2.0 bandwidth, it can't take full advantage of the PS5 with VRR or 4k @ 120Hz. However, it still works with other signals and downscales 4k signals, which results in a more detailed image than native 1440p.

The Acer Predator X27U has some limitations with the Xbox Series X|S. It doesn't support 1440p @ 120Hz, no matter the combination of settings, and VRR doesn't properly work with any resolution or refresh rate. Even if the console says it's on, it doesn't actually work, and the refresh rate stays fixed in games. The same issue occurs with different Xbox units as well. Essentially, you can only get a 120Hz refresh rate with a 1080p resolution, or you can get a higher 1440p resolution with a lower 60Hz refresh rate.

The USB-C port delivers enough power to charge most laptops while you're using them, and it also serves as an upstream port, so you can connect your mouse and keyboard to the monitor and use them with your laptop connected over USB-C.

The Acer X27U works well with macOS. Using the USB-C port, the max refresh rate is 120Hz, and you can get VRR and HDR simultaneously. However, HDR is dim, even darker than in SDR, and because the brightness is locked to its max in HDR, there's no way to fix this. If you're using a MacBook and close the lid, the image stays on the screen, but you can't control anything. When using a DisplayPort to USB-C cable, you can get the max refresh rate of 240Hz, but the same issues in HDR are present.

The Acer Predator X27U has a few extra features. Its KVM switch works well and allows you to easily switch between two sources and use the same keyboard and mouse connected to the monitor. It has other features, including:

• Black Boost: Adjusts gamma so that you can see opponents more easily in games.
• Constant Brightness: Minimizes the aggressiveness of the Automatic Brightness Limiter by making the screen dimmer. If you don't see this option, update the monitor's firmware.
• Game Assistant: Includes gaming options like a timer and virtual crosshairs.
• Image Retention Refresh: This is the only setting available to help reduce the risk of burn-in. When you manually start it, it runs a pixel refresh cycle. The refresh will run automatically when you turn the monitor off after more than four hours of use. A pop-up reminding you about image retention can also appear. Users have reported that it pops up with varying frequency and sometimes appears before users have used it for four hours.
• Power-Off USB Charge: When enabled, it still provides power to the USB ports even with the monitor off.
• Refresh Rate Num: Displays the current refresh rate of the display.