AOPEN 27ML1U Review: 27″ 1440p FreeSync IPS Gaming Monitor

The AOPEN 27ML1U is an affordable 27" 1440p IPS gaming monitor with AMD FreeSync up to 75Hz, motion blur reduction, and more cool features!

Bottom Line

The AOPEN 27ML1U is an outstanding monitor for its price. It is great for gaming, office use, and everything in-between. If you don’t care for 144Hz and competitive shooters, it’s the best monitor under $250.


The AOPEN 27ML1U is an affordable 27″ 1440p IPS display, which provides exceptional image quality for the price. It offers vibrant colors, wide viewing angles, clear details, and plenty of screen space. 

Plus, it has a motion blur reduction technology, AMD FreeSync up to 75Hz, and a quick response time speed, which makes it a great monitor for gaming.

Although you may not have heard of AOPEN, they actually used to be a sub-Acer company. You will find many similarities to Acer’s monitors such as the same naming scheme (AOPEN 27ML1U bmiipx), OSD/user manual layout, “ZeroFrame” design, etc.

In other words, it’s not an off-brand company that uses second-grade panels, and the AOPEN 27ML1U is the proof of that.

Image Quality

The AOPEN 27ML1U monitor is based on an IPS panel with 10-bit color depth (8-bit + 2-bit FRC) and 100% sRGB color gamut. You get accurate, consistent, and vibrant colors.

IPS panels also offer wide 178-degree viewing angles, which ensure that the picture won’t shift in color when you look at the screen from different angles.

Other panel-related specifications include a 350-nit peak brightness, a 1,000:1 contrast ratio, a 75Hz refresh rate, and WQHD (2560×1440) screen resolution.

On the 27″ screen of the AOPEN 27ML1U, 1440p resolution provides the ideal pixel-per-inch ratio, which means that you get plenty of screen space and sharp details without scaling necessary.

Moving on, we didn’t detect any defects such as dead/stuck pixels or excessive IPS glow/backlight bleeding on our unit.

The monitor has a flicker-free backlight and a low blue light filter, which prevents eye fatigue and headaches caused by looking at the screen for extended periods.


Aopen 27ml1u Bmiipx Review

A 75Hz refresh rate provides a small boost in motion clarity and gameplay fluidity, but don’t expect a significant improvement over the standard 60Hz displays. For fast-paced and competitive games, we recommend getting a 1080p 144Hz monitor instead.

However, if you mostly play the latest AAA titles and more graphically-oriented games (or games that are locked to 60FPS), the AOPEN 27ML1U 1440p gaming monitor is a better option for you.

The AOPEN 27ML1U input lag is only ~10ms, which makes for imperceptible delay between your actions and the result on the screen.

Further, the response time speed is around 4ms, which is enough to eliminate all prominent trailing of fast-moving objects.

For CRT-like motion clarity, you can enable the TVR (Turbo Visual Response) feature, which via backlight strobing reduces the perceived ghosting and motion blur.

Backlight strobing also decreases the monitor’s maximum brightness while active, so use it only in fast-paced games if you prefer it; otherwise, make sure it’s disabled.


27 Inch 1440p Ips Freesync

The AOPEN 27ML1U 27″ 1440p IPS gaming monitor supports AMD FreeSync.

If you have a FreeSync-compatible graphics card by AMD or NVIDIA, FreeSync will provide you with a variable refresh rate (VRR), which eliminates screen tearing and stuttering without affecting input lag.

FreeSync works without issues with compatible NVIDIA cards, too.

The VRR range of the AOPEN 27ML1U is only 48-75Hz/FPS, so LFC (Low Framerate Compensation) is not supported, meaning that under 48FPS, VRR won’t work.

Using CRU, you should be able to increase the VRR range to ~40-75Hz and maybe even further depending on your particular unit of the display.

Note that you cannot use FreeSync and TVR simultaneously.

Further, if you enable FreeSync, you can only use the ‘Normal’ response time option, not ‘Extreme’ which is actually common for Acer’s FreeSync monitors and not a big issue for the AOPEN 27ML1U as there isn’t any particularly noticeable ghosting even with the ‘Normal’ response time overdrive setting.

Other gaming features include Black Boost (increases visibility in dark games), Aim Point (custom crosshair overlays), and three customizable picture presets. The monitor also offers advanced picture adjustments, including gamma and 6-axis hue/saturation.

Design & Connectivity

Aopen 27ml1u Amazon

As far as the ergonomics are concerned, you can only tilt the screen by -5°/15°. Luckily, the stand is easily detachable, allowing you to effortlessly mount the screen on a third-party stand via the 100x100mm VESA pattern.

Connectivity options include two HDMI 2.0 ports, DisplayPort 1.2, a headphone jack, and an audio line-in for the 2x2W integrated speakers. FreeSync works over both HDMI and DP, so you can use it with Xbox One consoles as well.

The monitor has the common ZeroFrame design that’s found on modern Acer displays.

The bezels are very thin, which makes it perfect for multi-monitor setups, but there’s also a narrow black border around the screen, which is standard for these ‘bezel-less’ monitors.

Price & Similar Monitors

The AOPEN 27ML1U price goes for around $230-$250, which is well worth the price considering that there aren’t many 27″ 1440p IPS monitors with FreeSync available.

Sadly, it’s no longer available. We recommend checking out the LG 27QN600 as the alternative; it’s based on the same panel and offers similar features.

However, for gaming, you should get a 144Hz gaming monitor instead, such as the Acer XV272U which is available for $250 – $300.

For a mix of color-critical work and light gaming, we recommend the ASUS PA278QV IPS monitor with excellent factory-calibration and FreeSync up to 75Hz.

To learn more about monitors and ensure you’re getting the model most suited for your personal preference, visit our comprehensive and always up-to-date best gaming monitor buyer’s guide.


27″ 1440p monitors provide the perfect screen size/resolution ratio while IPS panels offer a good balance of image quality/performance in comparison to TN and VA panels.

Until now, there weren’t any 27″ 1440p non-144Hz IPS models available that were tuned for gamers. So, AOPEN finally gave us a choice of an excellent yet affordable 1440p gaming monitor.

Screen Size27-inch
Resolution2560×1440 (WQHD)
Panel TypeIPS
Aspect Ratio16:9 (Widescreen)
Refresh Rate75Hz
Response Time4ms (GtG)
Motion Blur Reduction1ms (MPRT)
Adaptive SyncFreeSync (48Hz-75Hz)
PortsDisplayPort 1.2, 2x HDMI 2.0
Other PortsHeadphone Jack
Brightness350 cd/m2
Contrast Ratio1000:1 (static)
Colors1.07 billion (8-bit + FRC)
VESAYes (100x100mm)

The Pros:

  • Excellent value for the price
  • Vibrant colors, clear details, and plenty of screen space
  • Plenty of gaming features including FreeSync and TVR

The Cons:

  • Tilt-only stand
  • Narrow FreeSync range out of the box

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Rob Shafer

Rob is a software engineer with a Bachelor’s degree from the University of Denver. He now works full-time managing DisplayNinja while coding his own projects on the side.