Acer Predator XB273K 4K 144Hz Monitor Review: The Next Best Thing

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Grayscale, Gamma & Color

The XB273K truly is a monitor that can be called “factory calibrated.” The Standard and User picture modes require zero adjustment to achieve perfect color accuracy.

Grayscale & Gamma Tracking

We describe our grayscale and gamma tests in detail here.

Our three grayscale and gamma charts look identical regardless of whether we choose the DCI-P3 or sRGB color gamut. Grayscale also isn't visibly affected by the brightness setting. This is the way it should be; controls that don’t interact and accuracy that remains consistent regardless of color mode. The difference in grayscale error between the XB273K at max brightness versus 200 nits is well below the visible point. Gamma is equally consistent with just a small dip at the 10 percent brightness level. The result is slightly clearer shadow detail, so we don’t consider it a problem.


The XB273K wins this out-of-box test by a comfortable margin. The X27 also comes with a factory calibration but can’t quite reach the same high levels found in our review subject. The other screens have slightly visible grayscale errors before calibration.

We didn’t calibrate the XB273K, but we did record a slightly higher average grayscale error after setting the backlight to 200 nits. This is well within the acceptable range, as there was no visible difference when viewing actual content (or test patterns).

The dip in gamma at 10 percent brightness spoils the gamma range result slightly, but the average value is right on the standard at 2.2. This is essentially perfect luminance with a tiny bit of extra shadow detail boost, not a bad thing. And the gamma tracking is good enough to ensure excellent results in the color gamut test.

Color Gamut Accuracy

For details on our color gamut testing and volume calculations, click here.

You can view SDR content in either the sRGB or DCI-P3 gamuts. For accuracy’s sake, we chose sRGB, but some prefer the extra color afforded by DCI. Either way, expect spot-on color. All sRGB color points are either inside of or in contact with their target boxes. The DCI gamut adds a bit of bonus red and blue with a slightly under-saturated green primary. The errors are still well below the visible threshold, so we can chalk this up as another win. Remember, no adjustments were necessary to achieve these results.


The XB273K delivers superb color right out of the box in both sRGB and DCI-P3 modes. It performs as well, if not better, than any premium professional monitor we’ve tested. Both modes have no visible errors, and DCI offers just a bit of extra punch for blue and red. Again, we have to emphasize this is reference-level performance.

Acer claims 90 percent DCI-P3 coverage and manages to come close at 87.65 percent. That is a miniscule difference, and when compared to other premium DCI screens, it competes with them impeccably. The same is true in sRGB mode, and we have no issues with what we’re seeing here. The XB273K is a high-quality, reference monitor equally justifiable for high-end professional graphics and video applications as it is for gaming.

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Christian Eberle
Contributing Editor

Christian Eberle is a Contributing Editor for Tom's Hardware US. He's a veteran reviewer of A/V equipment, specializing in monitors. Christian began his obsession with tech when he built his first PC in 1991, a 286 running DOS 3.0 at a blazing 12MHz. In 2006, he undertook training from the Imaging Science Foundation in video calibration and testing and thus started a passion for precise imaging that persists to this day. He is also a professional musician with a degree from the New England Conservatory as a classical bassoonist which he used to good effect as a performer with the West Point Army Band from 1987 to 2013. He enjoys watching movies and listening to high-end audio in his custom-built home theater and can be seen riding trails near his home on a race-ready ICE VTX recumbent trike. Christian enjoys the endless summer in Florida where he lives with his wife and Chihuahua and plays with orchestras around the state.