Acer ConceptD CM3271K 4K Monitor Review: Colorful and Bright 27-Incher

Color gamut options that'll make pros smile

Acer ConceptD CM3271K
(Image: © Acer)

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We performed all calibration tests in the CM3271K’s User mode. We also measured the gamut presets corresponding to the most commonly used standards, Adobe RGB, DCI-P3 and sRGB.

Grayscale and Gamma Tracking

We describe our grayscale and gamma tests in detail here.

Regardless of the chosen gamut, default grayscale tracking was the same. We could see a slight purple tint from 30% on up and the average error was around 5.8 Delta E (dE). Gamma stays close to the 2.2 mark in every case with a slight drop at 70-90%. This means higher brightness levels are a tiny bit too high. The error is hard to spot in actual content.

Calibration in the User mode produces excellent grayscale tracking with no visible errors. Gamma remains the same. The CM3271K includes other gamma presets, all of which measure correctly. If you set 2.4, you get 2.4.


Though the CM3271K is aimed at creative professionals, its out-of-box grayscale accuracy is a little below par. We would expect default numbers to be around 3dE or less. The 5.89dE value shown above represents the User mode though all other gamut modes measured within 0.2dE of that. Calibration in the User mode makes a visible improvement but then you are restricted to the General gamut which is nearest to Rec.2020.

Gamma accuracy is good with a tight range of values and tracking that averages 2.11, 4.09% off the 2.2 spec. This is solid performance.

Color Gamut Accuracy

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

The CM3271K’s native color gamut is best measured against the Rec.2020 standard. You can see in the first chart that it is on or close to most targets with a linear rise in saturation. It only comes up a little short of the full gamut which is impressive. This is a seriously colorful display. When viewed next to a typical sRGB screen, the difference is quite obvious.

Calibration lowers the average error to 2.48dE when compared to Rec.2020. Other gamut modes measure very close to their targets as well with average errors around 3.1dE and full coverage. We’ve measured Adobe RGB, DCI-P3 and sRGB for today’s tests.


(Image credit: Tom's Hardware)

The CM3271K’s 2.48dE score represents the calibrated User mode with the General (Rec.2020) color gamut in place. Other gamut modes have average errors around 3.1dE so it’s safe to say that color performance is similar in all presets. We wish there were more calibration options in the various gamut modes to correct grayscale tracking. But at this monitor’s price point, it delivers solid accuracy. One could correct the grayscale flaws with a software solution like CalMAN and a software lookup table.

We’ve charted the gamut volumes for sRGB (97.59%) and DCI-P3 (89.49%). These are measured in their respective color modes. Adobe RGB volume was calculated at 98.21% while Rec.2020 coverage is an impressive 74.9%. The CM3271K is qualified for color-critical work when a software profile is used. If you’re working in Rec.2020, you can calibrate in the OSD and forgo the need for additional lookup tables.

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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.

  • ingodwestream
    Is this a better pick for video/photo/office vs BenQ PD2700U? 4K and color accurate is top priority.
  • kkruecke
    Thanks for the CM3271K review and for the suggested User mode settings mentioned in the review.
  • Pro.swe
    Thanks a lot for this great review. I have one of this and a colorimeter. Which are the differencies is using "Acer Calibrator" software for calibration or the colorimeter software with icc profile? Does this monitor support hardware calibration? I cannot find clear information about this