• Editors' Choice

Asus PQ321Q Review

The Asus PQ321Q is a professional display, and it acts like one.

$5,249.99 at Amazon

Behind the Screens

The Asus PQ321Q is an odd bird, even for a 4K panel. Instead of a single, 32-inch 3,840 x 2,160 panel, this monitor is actually two 1,920 x 1,080 panels, side-by-side—it only looks like one panel.

The panels obviously do everything in tandem, but can also be split to display two 16-inch 1080p images. What's even more impressive is how high-quality this Asus looks, right out of the box. Whether it's handling two 1080p images or a single 4K image, it's right on target.

Color Gamut

The PQ321Q flaunts a color depth of 10 bits, which means it's capable of more color saturation than many other computer monitors, most of which utilize 8-bit color. Thus, this Asus covers a little more than the sRGB color gamut, the current digital color standard.

The Asus PQ321Q's red, blue, and green primaries weren't completely flawless, but they were well within acceptable error margins for digital color production—likewise with the cyan, magenta, and yellow secondaries. I was also very impressed with the PQ321Q's white/gray points, which were almost perfect.


Grayscale Error

When dealing with display devices, the grayscale refers to the spectrum of black/gray/white along video intensity inputs. Computer monitors create gray and white by combining red, green, and blue sub-pixels—this is called "additive color." Ideally, each point along the grayscale should correspond to the same x- and y- coordinates in the color space, to ensure that the color temperature of the grays and whites is the same. When the color temperature sways from the D65 ideal, a sum of error is recorded in DeltaE.

After a short warm-up period, the PQ321Q tested with a grayscale DeltaE of 2.27, which is quite low. Grayscales with a DeltaE of 3 or below are generally considered acceptable by modern display standards, so this is a good result.


RGB Balance

RGB balance refers to the input level of a display's red, green, and blue sub-pixels relative to one another. Ideally, the monitor will neither over-emphasize nor under-emphasize any one sub-pixel across the grayscale intensity range, which is what helps to maintain an even correlated color temperature or white point.

I measured a very well-maintained RGB balance while testing the PQ321Q—the blue sub-pixel is favored slightly, but not overmuch, and never to the point of visibility. This isn't a perfect result, but it is very good nonetheless.


Gamma Sum

Gamma refers to the light intensity allocation to each step along the grayscale. A higher number, such as 2.6, refers to a gamma curve that very gradually leaves black and enters middle-gray and white. A lower number, such as 1.8, refers to a much faster gamma curve, one that exits black almost immediately.

We measured an almost perfect 2.4 gamma, the ideal slope for a dark or black room—which is exactly where the PQ321Q was tested. This was the pre-set in sRGB mode, so users looking for a brighter gamma (such as 2.2 or 2.0) may want to set the monitor up in Standard mode so that gamma can be tweaked more easily.


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