Dell UltraSharp U3224KB 32-inch 6K Monitor Review: 21 Megapixels Of Flexible Productivity

Dell’s UltraSharp U3224KB is a 6K (6144x3456, 21.23MP) IPS 32-inch monitor with wide gamut color, HDR 600, KVM functions and a built-in webcam with microphone.

Dell UltraSharp U3224KB
(Image: © Tom's Hardware)

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The U3224KB is intended to be a setup-and-forget monitor. It doesn’t need calibration in any of its picture modes. I tested the Standard, Color Space and Custom Color presets.

Grayscale and Gamma Tracking

Our grayscale and gamma tests use Calman calibration software from Portrait Displays. We describe our grayscale and gamma tests in detail here.

Right out of the box, the U3224KB meets the numbers on its included calibration data sheet. In my test, only 80 and 100% brightness show any DeltaE values over 3, which is the visible threshold. You won’t see these errors in actual content. The gamma run shows a slight rise (too dark) from 60 to 90%, which is extremely hard to spot. I have no complaints here.

Calibration of the Custom Color mode improves grayscale tracking but makes the 80 and 90% gamma values a little darker. This is minor, and the images look nearly identical in a side-by-side comparison.

Should you choose the Color Space mode, you can shrink the gamut to sRGB if you want that color space for video or photography work. Grayscale and gamma tracking are almost perfect except for a light luminance value at 10% brightness. This minor error will be hard to see in actual content.


Compared to the other screens, the U3224KB runs with the pack. Only the PA32DC will show a visible error. The others look identical in a direct comparison of test patterns and real content. With calibration, the results do not change visually but the ViewSonic has the best numbers. However, none of the monitors have a visible issue.

Gamma performance is also very close among all six displays. Only the Samsung has a significant deviation from the 2.2 standard. It runs a tad dark in tone compared to the others. The U3224KB has visually perfect gamma with all values on or close to 2.2 in a very tight range.

Color Gamut Accuracy

Our color gamut and volume testing use Portrait Displays’ Calman software. For details on our color gamut testing and volume calculations, click here.

The U3224KB’s color gamut tests revealed a very accurate display. By default, the gamut errors are well below the visible threshold. Calibration makes no visual difference but improves the measurements by a small amount. With 100% coverage of DCI-P3, no color comes up short of its saturation targets. Most wide-gamut screens are slightly deficient in green but not this Dell. It hits all the marks.

In sRGB mode, red is a tad under-saturated on the chart, but the actual errors are less than 3dE, below the visible level. This is excellent performance.


The U3224KB would place third in this group, whether calibrated or not. That says a lot for Dell’s quality control. You are paying a premium for this monitor, but you’re getting one of the best screens available today. It truly doesn’t get better than this.

Though the ViewSonic and Asus displays have larger color gamuts, a professional workflow benefits most from 100% coverage of a gamut standard, no more, no less. The U3224KB checks that box. And it’s only a tad short of 100% in the sRGB mode as well. This is a pro monitor in all respects. Given the cost of some high-end monitors, the Dell’s price is very competitive.

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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.