Cooler Master launched the GM27-CQS in early 2023. This is a 27-inch curved monitor offering QHD resolution at a reasonable price. This 27-inch gaming monitor is also DisplayHDR True Black 400 certified.
Let’s see in real life how this MGM27-CQS monitor from Cooler Master performs, which will cost you €219.
Cooler Master GM27-CQS specifications:
- Ultra-Speed VA
- QHD resolution (2560×1440)
- HDR400-certified brightness – up to 90% P3 color coverage
- 4000:1 contrast
- 178° viewing angles
- 0.5ms response rate
- Maximum frequency of 170Hz
- FreeSync Premium
- VESA 100x100mm
- 1x DisplayPort 1.4a
- 2x HDMI 2.0
- 130mm height adjustment
Design
The GM27-CQS adopts a very gaming design. The edges are slim, measuring approximately 9 mm. The foot, in the shape of Cooler Master’s hexagonal logo, is wide and solid. The fixing system is solid, the stand is stable and features a quick-release system . There’s also a VESA 100×100 mm mounting system. In terms of ergonomics, the screen is also height-adjustable (13cm). Cooler Master offers a very aggressive design on the rear of the screen, but without RGB .
To adjust the screen, there’s a mini joystick on the back of the screen, which simplifies settings in the OSD. No software for Cooler Master, which offers a simple, effective screen.
[nextpage title=”Test methodology”]
Test methodology
We want our monitor tests to be as objective as possible. We therefore do not use subjective comments in our scoring. The scores are derived from numerical analyses. We use Datacolor’s SpyderX Elite probe to assess display quality. And we use a custom-made probe to test input lag at the screen’s maximum refresh rate. These results add extra utility to our tests, enabling us to compare features more accurately.
For the tests, we don’t touch the screen’s default settings. We just adjust the brightness for the test of this one, as the vast majority of buyers will change the default values little or not at all, and don’t own a calibration probe. This also shows how much time the brand spends making the screen look good right out of the box.
[nextpage title=”Backlight leakage”]As far as backlight leakage is concerned, there was nothing notable with the screen switched on against a black background in a room with as little light as possible. A good result.
In the photo, we’ve sharply increased contrast to show the uniformity of blacks. To the naked eye, differences are hardly perceptible.
Please note: this subjective observation is not taken into account in our rating system, which is designed to be as objective as possible.
[nextpage title=”Viewing angle”]Being a VA panel, viewing angles are generally very good. The GM27-CQS is no exception to the rule, and does very well indeed..
Please note: this subjective observation is not taken into account in our rating system, which is designed to be as objective as possible.
[nextpage title=”Ghosting”]For this test, a certain methodology must be applied. You can perform the tests yourself on your screen by following these instructions.
At 170Hz, sharpness is rather average. Ghosting is most noticeable on dark backgrounds.
Please note: this subjective observation is not taken into account in our rating system, which is intended to be as objective as possible.
[nextpage title=”Color range & accuracy”]
Color range / Gamut
Gamut is the set of colors that a device can display. Note that any score above 90% P3 is excellent. A high refresh rate and adaptive synchronization are nice features to have, but gamut and color shouldn’t be sacrificed either. SRGB coverage : 99%; AdobeRGB: 84%; DCI-P3: 90% (exactly the score announced in the specs).
Color accuracy
For this measurement, we want Delta-E to be as low as possible. An average Delta-E of less than 2 is considered good. The average score of the Cooler Master GM27-CQS is 1.37, which ensures good color quality.
[nextpage title=”Color uniformity / Luminance”]
Color uniformity
Uniformity varies between tiles in the same production run, so always take its values as a trend. We generally aim for a color variance of less than five. Obviously, the larger the screen, the more difficult this becomes. The GM27-CQS once again achieves a very good score, below 3.1.
Luminance uniformity
Luminance uniformity is generally expected with a maximum score of around 10%, but the larger the screen, the more difficult the task. The Cooler Master GM27-CQS displays a maximum of 13% at the bottom of the screen, clearly this display’s weak point.
[nextpage title=”Brightness levels and contrast ratio”]
We measured 301.9 nits using the screen’s default settings. Whites are stable and perfect at around 80% brightness.
VA panels have good blacks, obviously not at the level of OLED screens. Contrast is 2310:1 (without enabling HDR) and blacks are 0.10 at 200 nits, which is a decent score for a VA panel.
[nextpage title=”Input lag”]Measuring input lag is very different from measuring refresh rate. Input lag is the time taken by the video signal between input to the video port (HDMI/DisplayPort) and display of the image on the screen. Few manufacturers communicate this value, even though it is crucial for gamers. A refresh rate of 1ms is useless if input lag is high. It’s important to note that the more pixels there are to display, the greater the input lag. It will therefore be hard to find very good results on a 4K screen.
Another important piece of information is that not all pixels are displayed at the same time: refresh is from top to bottom. So we’ll find a much better response time at the top of the screen than at the bottom. We take 3 measurements (top, center, bottom) and calculate the average for our rating.
Notation :
- 5 stars – Less than 4ms lag – excellent, e-sport screen
- 4 stars – From 4ms to 8.33 ms – equivalent to one frame lag at 120 Hz refresh rate – good for competitive gamers
- 3 stars – 8.33 to 12.33 ms – more than one frame lag at 120 Hz refresh rate – good for most gamers
- 2 stars – From 12.33 to 16.66 ms – less than two frames at 120 Hz refresh rate – good for most gamers, not recommended for FPSs
- 1 stars – More than 16.66 ms – equivalent to more than 2 frames at 120 Hz refresh rate – noticeable lag in everyday use, not optimal for fast games
The Cooler Master GM27-CQS scores well (5 stars) with 0.5 ms at the top of the screen, 3.6 ms in the middle and 6.7 ms at the bottom. An average of 3.6ms, which explains the 5 stars.
[nextpage title=”Conclusion”]
The Cooler Master GM27-CQS is on the market for €219. In short, this monitor’s performance is clearly up to scratch, with only the screen’s luminance uniformity lacking. A very good gaming monitor, it offers gamers the best performance for QHD resolution at a good price. Last but not least, calibration is the strength of this screen, which is almost flawless.
Cooler Master GM27-CQS
We liked:
- The price
- Excellent input lag
- Factory settings
- Very stable stand
Our least favorite :
- Luminance variation at the bottom of the screen
- Imposing stand
On arrival, the Cooler Master GM27-CQS hits the mark in a highly competitive market. With 170 Hz on a QHD screen, FreeSync Premium and HDR400, it’s ideal for gamers. All with a very good factory setting, this screen has a lot to please. We choose to award Gold to the GM27-CQS.