In this article, I’m comparing four 27-inch 1440p 240Hz OLED gaming monitors to determine the best option and which one is worth for you. The four contenders are the LG 27GR95QE, the Asus ROG Swift OLED PG27AQDM, the Corsair Xeneon 27QHD240, and the Acer Predator X27U. I’ve extensively tested all four of these monitors, so I’ll provide detailed and in-depth thoughts on their comparisons.
Specs
All four of these gaming monitors use the same LG Display WOLED panel, which is 27 inches in size and boasts a 2560 by 1440 resolution. They all operate the panel at a maximum refresh rate of 240Hz and support adaptive sync technologies. Some are branded as FreeSync, some as G-Sync Compatible, and some have both. However, in the end, you’ll enjoy perfect variable refresh rate support on all of these monitors, regardless of whether you’re using an AMD or Nvidia graphics card. Whether it’s branded as FreeSync or G-Sync has little to no difference for current generation monitors.
Design and Build Quality
Each of the four variants has a unique design, but all follow a similar template, differing in elements such as the stand to match the respective company’s design language. The display section across all models has roughly the same bezel size on all four edges, so the part you’ll be looking at most frequently is virtually identical regardless of the variant you choose. The back of each monitor features what I like to call the central box design, where a central section houses all the display processing hardware, with the thin OLED panel extending from it. This design is consistent across all four models, giving them a sleek and thin appearance at the edges.
As for the aesthetic aspect, that’s a matter of personal preference. All the well-built models primarily use dark plastic. The LG and Asus models incorporate RGB LED lighting on the rear, whereas the Corsair and Acer models do not. Nevertheless, regardless of your choice, you’ll get a monitor that looks appealing. This is also true for the stands; they are quite similar in appearance and functionality, supporting height, tilt, swivel, and pivot adjustments. However, some designs might offer more practicality than others. The LG and Corsair models have ports that protrude directly from the rear panel, making them easier to access. On the other hand, the Asus and Acer models have downward-pointing ports. It’s a minor distinction, but I find the LG and Corsair’s approach to be more convenient.
Ports and Connectivity
The port selection varies among the four models. All of them have DisplayPort 1.4 with DSC, providing the full 1440p 240Hz experience. Additionally, all four have two HDMI ports. Only the LG model boasts the full HDMI 2.1 experience, featuring 48-gigabit-per-second ports that allow uninterrupted 1440p 240Hz output. The Corsair model comes next with 24-gigabit-per-second HDMI 2.1, which provides the same experience as the LG for PC users but might be slightly less compatible with other devices. In contrast, the Acer and Asus models are disappointing as they only feature HDMI 2.0, limiting the HDMI ports to 144Hz instead of the full 240Hz.
There are also variations in USB connectivity. Corsair and Acer offer USB-C inputs with DP Alt Mode. The Corsair provides 65 watts of power delivery, while the Acer offers 90 watts, making both models suitable for single-cable laptop usage. Corsair also offers four USB-A ports in a hub, the highest among all models. The other three models have only two USB Type-A ports. Additionally, the Corsair and Acer models include a KVM switch, while the LG and Asus do not.
Three of the four models (Acer, Corsair, and Asus) use a directional toggle to control the on-screen display (OSD), whereas the LG model employs an easy-to-use remote with controls directly on the display housing. The Corsair variant also features a useful proximity sensor that displays a guide on the screen, making it easy to locate the OSD controls. Regarding OSD features, there isn’t a significant standout; the range of gaming features is quite similar across each model, with some differences in color controls that I’ll discuss further in this comparison.
Screen Coating, Subpixel Layout and Burn In
All four variants use the same panel, and this includes the application of a matte anti-glare coating. Currently, there is no glossy variant available on the market. However, the matte finish works well to minimize mirror-like reflections in brighter environments while still preserving black levels in other situations. It does have a slightly heavier feel, which some people might not prefer. Nevertheless, this finish is consistent across all models. So, if you’re opting for this overall hardware package, you’re bound to have this finish.
Similarly, the RBGW subpixel layout is uniform across all models. Text rendering appears the same across the four models due to this unique layout. Ultimately, I don’t believe any of these products excel in terms of text clarity. Furthermore, due to the use of OLED technology, all models are susceptible to permanent burn-in. Consequently, no variant here is highly suitable for productivity usage. I generally wouldn’t recommend any of these monitors for desktop applications involving extended periods of static content on the screen. However, all of them perform perfectly well for content consumption, where subpixel layout and burn-in concerns are not problematic.
It’s interesting to note that Corsair is the only company offering a burn-in warranty for their unit. In contrast, LG, Asus, and Acer have all chosen not to cover burn-in as part of their warranty. Therefore, if you prioritize peace of mind regarding burn-in, Corsair provides that assurance.
Response Time Performance
| LG 27GR95QE (27″ 1440p 240Hz WOLED) | 2.8% 0.20 |
| Asus ROG Swift OLED PG27AQDM (27″ 1440p 240Hz WOLED) | 0.7% 0.27 |
| Acer Predator X27U (27″ 1440p 240Hz WOLED) | 0.7% 0.27 |
| Corsair Xeneon 27QHD240 (27″ 1440p 240Hz WOLED) | 0.0% 0.35 |
Motion performance is highly similar across these four OLED monitors, so if you’re curious about response times and motion clarity, there’s minimal distinction among these models due to their shared panel. The LG variant exhibits slightly more overshoot than the other three, but this discrepancy is challenging to perceive except in instances of lower refresh rate gaming. The Corsair, Acer, and Asus models all deliver virtually indistinguishable performance, resulting in an exceptional 240Hz refresh rate gaming experience. In simple terms, speed will not play a pivotal role in choosing between these four variants.
| Monitor | Maximum Refresh Rate, Adaptive Sync On, SDR Mode |
|---|---|
| Asus ROG Swift OLED PG27AQDM (27″ 1440p 240Hz WOLED) | 0.1 | 2.2 | 2.4 |
| Acer Predator X27U (27″ 1440p 240Hz WOLED) | 0.1 | 2.2 | 2.5 |
| Corsair Xeneon 27QHD240 (27″ 1440p 240Hz WOLED) | 0.2 | 2.3 | 2.5 |
| LG 27GR95QE (27″ 1440p 240Hz WOLED) | 0.3 | 2.4 | 2.5 |
Likewise, input lag won’t be a determining factor because all four models provide essentially the same performance. Whether we’re discussing SDR or HDR latency, there’s a mere 0.2-millisecond gap in measured latency between the best and worst performers, which is practically identical. It’s important to note that none of these models support black frame insertion, meaning there’s no option for producing a strobed-like image to enhance clarity.
Color Performance
| Monitor | Peak Gamut Coverage Measured (CIE1976) |
|---|---|
| LG 27GR95QE (27″ 1440p 240Hz WOLED) | 72.9 |
| Acer Predator X27U (27″ 1440p 240Hz WOLED) | 72.8 |
| Corsair Xeneon 27QHD240 (27″ 1440p 240Hz WOLED) | 72.1 |
| Asus ROG Swift OLED PG27AQDM (27″ 1440p 240Hz WOLED) | 72.1 |
In terms of color quality, as they all utilize the same WOLED panel, we encounter identical color space coverage: approximately 97% DCI-P3 and about 72% Rec. 2020. There are no differences in color space coverage among the models. However, variations arise in terms of factory calibration. Out of the box, with no adjustments made, the Acer and Corsair models exhibit notably better grayscale accuracy compared to the LG and Asus models. The latter two models display a noticeable blue or cold tint. In contrast, the Acer and Corsair models approach the accurate 6500K point, resulting in improved Delta E values for SDR sRGB content. This difference also has a minor impact on saturation, though none of the four models come with an sRGB clamp enabled by default, resulting in similar oversaturation levels.
All four models feature an sRGB mode for grayscale, with the Corsair 27 QHD240 leading in terms of Delta E values. It’s followed by the Acer, LG, and Asus models, which are all positioned similarly. For Color Checker evaluations, the Acer model slightly outperforms the Corsair, followed by the Asus variant and then the LG model. If you intend to use these monitors for SDR desktop tasks, the Corsair and Acer variants are the ones to consider, with a preference for the Corsair model.
Nevertheless, all four models can be calibrated using software, leading to highly similar results. The LG model holds an advantage here, as it also supports hardware calibration through its PC app. However, the results from this approach aren’t as effective as proper software calibration and necessitate additional hardware. Despite this, it’s a unique feature supported by the LG model.
Brightness, Contrast, and Uniformity
| Monitor | Calibrated, SDR Mode, Max Brightness at 100% White |
|---|---|
| Asus ROG Swift OLED PG27AQDM (27″ 1440p 240Hz WOLED) | 243 |
| LG 27GR95QE (27″ 1440p 240Hz WOLED) | 198 |
| Acer Predator X27U (27″ 1440p 240Hz WOLED) | 136 |
| Corsair Xeneon 27QHD240 (27″ 1440p 240Hz WOLED) | 131 |
One of the primary distinctions among the four models lies in their brightness levels, particularly evident when considering SDR brightness. The Asus PG27AQDM stands out as the top choice for desktop app usage in brighter environments, capable of reaching a peak brightness of 240 nits. While not exceptionally high, it surpasses the LG model by approximately 23%, which achieves 198 nits. Falling significantly short in terms of brightness are the Acer and Corsair units, only offering 130 to 140 nits, rendering them less suitable for users who prefer a brighter display.
This concern is exacerbated by the absence of the option to disable the automatic brightness limiter (ABL). Consequently, brightness constantly fluctuates as you move around or resize desktop applications, a particularly vexing issue. However, on the Corsair and Asus models, a setting known as uniform brightness or something similar can be activated to disable this behavior and maintain brightness levels consistent with those shown in the chart. On the other hand, the LG model lacks any ABL, but it permanently limits SDR brightness to roughly 200 nits.
For those using their monitors in dimly lit environments, the Acer and LG models are ideal choices. The Asus and Corsair models also offer respectable results, albeit not quite as impressive. All four models produce true black levels due to their utilization of OLED technology, resulting in an effectively infinite contrast ratio. Furthermore, they all share excellent viewing angles.
Regarding uniformity, there are minimal differences among the various panels. The Asus model exhibited slightly superior uniformity in my experience, but the variance was minor when compared to the other models. Similarly, all four models exhibit the same peculiar issue with gray uniformity, wherein dark gray tones appear slightly uneven or ‘dirty.’ This problem is not unique to a single variant; unfortunately, all of them suffer from this drawback.
HDR Performance
In terms of HDR performance, all units exhibit the same inherent OLED qualities, such as per-pixel or local dimming, true black levels, precise control over bright and dark regions, and excellent shadow detail. These attributes hold true across all four models. However, significant differences arise in HDR accuracy and brightness, which are worth exploring.
To begin with, only the LG and Asus models accurately adhere to the HDR10 PQ EOTF curve. As seen in both these models, the measured gray performance line aligns perfectly with the expected curve represented by the yellow line. The Acer model displays elevated brightness for certain segments of its curve, while the Corsair model exhibits both raised and lowered sections. If your goal is to display HDR content with the highest accuracy on your screen (bearing in mind that calibrating HDR is notably more challenging than SDR), the LG and Asus models are the top choices.
Moreover, there are variations in HDR brightness. Similar to SDR content, the Asus model shines as the brightest in HDR, reaching up to 196 nits for full-screen Windows. Conversely, the other three models hover around 140 nits, giving the Asus model a 40-nit advantage. This distinction also holds for 10-window brightness, where the Asus model reaches 906 nits compared to approximately 665 nits for both the LG and Corsair models, and 633 nits for the Acer variant. Consequently, the Asus model significantly outshines its competitors in terms of HDR brightness.
This discrepancy becomes evident when examining brightness versus window size. This brightness advantage isn’t solely apparent in synthetic tests; it’s also observable during gaming. In a real-world gaming scene, I recorded a peak brightness of 850 nits on the Asus model compared to 616 nits on the Corsair, 591 nits on the Acer, and 585 nits on the LG model. Once again, the Asus model boasts around a 40% brightness advantage.
Although the Asus model isn’t consistently brighter in all scenarios, it generally holds this advantage in our real-world testing. Some models exhibit certain peculiarities in HDR performance. For instance, when transitioning between SDR and HDR modes, the Acer model necessitates adjusting a setting in the OSD every time. Ideally, these settings should switch automatically for the optimal experience. If you’re using the uniform brightness setting with the Corsair model, you must manually disable it when switching to HDR mode, repeating the process each time. Similarly, both the LG and Asus models require firmware updates for optimal HDR performance. Fortunately, all four variants support firmware updates, so it’s possible that some of these issues, particularly those affecting the Acer and Corsair models, could be addressed in future updates.
Final Thoughts
After thoroughly examining all four 27-inch 1440p 240Hz OLED gaming monitors, it’s clear that there are only a few distinctions between each unit. This is to be anticipated, considering they all employ the same LG Display WOLED panel. Yet, these differences are substantial enough to allow for a conclusive evaluation of the best model, at least in my view. Here’s how I would rank these models from least to best:
In last place is the Acer Predator X27U. It boasts the lowest peak brightness among the tested models, exhibits less accurate HDR presentation, and suffers from bothersome firmware quirks like the inability to disable the automatic brightness limiter and challenges in switching between HDR and SDR modes. Priced at $1000 USD, it’s also on the higher end in terms of cost. Although Acer has some notable features, like 90 watts of USB-C power delivery (making it laptop-friendly) and a well-calibrated sRGB mode, these aspects alone are insufficient to warrant a recommendation from me.
In third position, I place the Corsair Xeneon 27QHD240. Its brightness aligns with that of the Acer model, indicating a lackluster performance. Similarly, it faces challenges with HDR accuracy. However, it is less burdened by firmware issues, and the automatic brightness limiter can be deactivated. In terms of ports, it’s the most well-equipped, featuring HDMI 2.1, USB-C with 65 watts of power delivery, and a four-port USB hub. Its SDR factory calibration is also impressive, surpassing the LG and Asus models. Notably, Corsair distinguishes itself by offering burn-in coverage with their warranty. Priced at $999 USD, the Corsair model is worth considering, though I can’t rank it higher.
In second place, I have the LG 27GR95Q8, which only slightly surpasses the Corsair model. It offers superior SDR brightness and better HDR accuracy. It’s the sole model with full bandwidth 48 gigabits per second HDMI 2.1 ports and Hardware calibration support. Competitively priced at around $900 USD, with occasional sales dropping it to $800, it’s an enticing choice. However, certain trade-offs prevent it from ranking higher. For example, its SDR mode calibration falls behind the Corsair and Acer variants, and it lacks USB-C input or a KVM switch. It also exhibits slightly more overshoot at lower refresh rates, and its overall brightness lags behind the Asus model.
At the top spot, I name the Asus ROG Swift OLED PG27AQDM. The key factor influencing this decision is its significantly higher SDR and HDR brightness, combined with excellent HDR accuracy post a firmware update. Typically 30% to 40% brighter, this model’s OLED advantage provides a distinct edge. While this extra brightness could contribute to faster panel degradation, I don’t foresee it being a major issue for gaming or content consumption. Notably, Asus doesn’t include burn-in coverage in their warranty, which is disappointing. Despite this, the Asus model doesn’t exhibit any significant issues that would deter me from recommending it. Its SDR and HDR brightness advantages, combined with solid HDR accuracy, place it at the forefront of this comparison. However, it’s worth considering the $1000 USD price tag and weighing it against the LG model’s competitive pricing.
In summary, after thorough evaluation, the Asus ROG Swift OLED PG27AQDM emerges as the winner in my opinion. Its superior brightness and HDR accuracy set it apart, despite the trade-offs. Ultimately, your decision should consider the price difference, additional features, and specific requirements you have for a gaming monitor. You can also explore individual reviews for more detailed insights on each product.
