Dell UltraSharp 32 6K Monitor U3224KB review: a big monitor for pro use

This 6K resolution monitor from Dell offers excellent colour accuracy and wide dynamic range – but it doesn't come cheap

(Image credit: Dell)
T3 Verdict

6K resolution is a pretty niche spec at the moment, but the Dell UltraSharp 32 doesn't half live up to its name and look superb! Add super-convenient Thunderbolt 4 connectivity and a smart design and this monitor has a lot going for it. It’s not really one for general users at this price, but those pros staring at a screen for work all day will definitely appreciate it.

Reasons to buy
  • +

    Accurate colour and plenty of screen real-estate

  • +

    Built-in KVM features for multiple computers

  • +

    Thunderbolt 4 connectivity is a blessing

  • +

Reasons to avoid
  • -

    Very expensive!

  • -

    Not really for gaming

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Sometimes things aren’t about size. For computer monitors, the more critical thing is resolution, because you sit close to one. That's why the best 4K monitors are revered, but just how much more detail can you pack onto a screen? 

The Dell U3224KB has one answer: this is a relatively small 32-inches across, but has an ultra-high 6144 x 3446 pixel resolution, typically called 6K. Multiply that out and it's greater than a massive 21-million pixels – which makes 4K's just-over-8-million-pixels sound paltry!

Using the aptly-named Dell UltraSharp means that you can have a full-resolution view of 4K video on screen, but still have plenty of room for the controls of your video editing programme. It also means you can view 6K videos shot by many professional video cameras at full resolution. It supports pro colour as well, with 100% Rec.709 and 99% P3. But given the price, can it really claim to be one of the best Dell monitors? Let's find out.

Dell U3224KB: Price & availability

Are you sitting down? You might want to. The Dell U3224KB will set you back a hefty $3,199/£2,542/AU$3,759 from Dell's own website. 

This is a 32-inch monitor, let's not forget, and you can buy many of the best 4K TVs for less than that at 65-inch scale! They serve different functions, though, and for many this Dell monitor will be worth its asking price in a pro setup.

Dell UltraSharp U3224KB review: Design & features

Dell UltraSharp 6K 32-inch U3224KB

(Image credit: Future)

The U3224KB has an attractive, clean design with a bezel around the 32-inch screen and a flat metal base. It’s a rather corporate-looking design, but it is functional: a hole in the back of the column routes the cables from the computer to the display, so they are hidden from view. 

The stand can tilt the monitor back and forth by about 25 degrees, and left and right by 60 degrees. It can also be rotated to portrait mode, although it is a tight squeeze if you have anything on your desk in front. The base can be replaced by a VESA 100 stand or mount too.

The main input for the U3224KB is a Thunderbolt 4 port on the base behind the display panel. This single connection carries the video signal, power, audio, and connects other devices. It can supply up to 180W of power to a laptop too.

As well as the Thunderbolt 4 input, the U3224KB includes HDMI 2.1 and mini DisplayPort 2.1 inputs, plus two USB-C upstream and five USB-A ports, which means there is no shortage of ways to connect devices. A gigabit Ethernet port is also present. 

These can all be switched between with the Auto KVM (keyboard, video, mouse) feature, which switches between the video and other inputs from the keyboard, so you can connect two devices to the monitor and control them both from one keyboard and mouse, switching between them with a key combination you set in the Dell Display Manager. That’s an incredibly useful feature if you have a work laptop and a personal computer. 

Dell UltraSharp 6K 32-inch U3224KB

(Image credit: Future)

The U3224KB can also display the image from two inputs side-by-side or show one image as a picture-in-picture preview. That’s handy if you're waiting for a video to render for example: you can switch to your laptop but still see how the render is progressing.

Including Mini DisplayPort rather than the more commonly used larger type is odd, but the port is used in many workstations and high-end PCs. A cable is included (which also has a locking bolt at both ends) but at just 40 inches long, it wouldn’t stretch far enough to reach my computer under my desk: I had to move it onto the top of my desk, which already has enough junk on it. Fortunately, DisplayPort cables (including ones that go from the larger type of socket to the mini type) are pretty cheap.

A 4K webcam is built into the top of the monitor frame. It’s more prominent than most, built into a circular enclosure that can be tilted up or down by about 20 degrees: useful for getting you right in the centre of the frame when you are sitting closer to the screen. It can’t be tilted left or right, but it does include software-switchable viewing angles of 65-, 75-, and 90-degrees.

Dell UltraSharp 6K 32-inch U3224KB

(Image credit: Future)

Two 14W speakers beside the camera produce decent sound, although it lacks the punch and bass feel of a decent set of desktop speakers. It is also odd to hear the sound coming from the top of the monitor rather than the bottom, but it works well for video conferencing.

The dual microphones next to the camera captured voices adequately in my testing, but my captured voice sounded rather flat, and the microphone picked up some background noise. That would be fine for video conferencing in a quiet environment, but if you are working in a noisy office or appearing on CNN, get a headset.

One nice touch here is a series of touch buttons on the frame to hang up a call, control the volume, and disable the camera and microphone: a plus for the paranoid and cautious. When the camera turns off, an internal shutter drops into place with a satisfying click.

Underneath these buttons on the bottom edge of the monitor is another nice touch: a slide-out panel with two USB-C and one USB-A port, perfect for devices like thumb drives that you want to plug in occasionally without reaching around the back of the display.

Dell UltraSharp U3224KB review: Image Quality

Dell UltraSharp 6K 32-inch U3224KB

(Image credit: Future)

I was very impressed with the image quality of the U3224KB. Monitors like this aren’t about producing the garishly bright colours of 3D games, but instead, focus on colour accuracy and dynamic range. 

The dynamic range of this monitor is excellent: I found that it could produce deep, solid blacks right next to bright whites. I measured the maximum brightness of the screen at an impressive 509 Cd/m2, which is very bright for a monitor this size, so it would have no problems cutting through office lighting. 

This is the first 32-inch monitor to use Dell’s IPS Plus panel, which uses a thicker panel inside the display to block more of the backlight and produce deeper black. It’s an effective technique that seems to work well: even with the brightness at maximum, I measured a patch of black on the screen at 0.33 CD/m2, meaning that Dell’s claim of a 2000:1 contrast ratio is pretty much spot on. 

The same was true of the colour gamut: it reproduces the entire Rec.709 colour gamut and managed most of the much wider professional DCI-P3 gamut, only missing a small piece of the green axis. It supports DisplayHDR 600 but does not support other HDR standards. With a refresh rate limited to 60Hz, this isn't going to be one of the best gaming monitors, but it'll be good enough for most.

Even without calibration, the colour accuracy of my review model was almost perfect, with excellent reproduction across the spectrum. I also calibrated it with my Spyder X but found that the custom profile was almost identical to the one that came with the monitor.

And yes, before you ask, I did try games on it. Doom Eternal running at the full 6K resolution was an impressive sight, albeit one that had steam coming out of the back of my graphics card. 

Dell UltraSharp 32 6K Monitor U3224KB review: Verdict

Dell U3224KB

(Image credit: Dell)

So is the Dell UltraSharp 32 6K Monitor worth it? For most people, the answer is no. The U3224KB is a great monitor, no doubt, but it is very expensive. Those who can justify it are those who make a living on their computer in front of a screen that requires these kinds of credentials.

Video editors and photographers can see more of an image at once or fill the extra space with controls or buttons that are normally hidden away. Coders can see more code on the screen simultaneously, especially with this big monitor in portrait mode. The built-in webcam and speakers aren’t strictly necessary for these users, but they are a great bonus if you do a lot of video conferencing.

Also consider

There are lots of 4K monitors available, but 6K models are a bit thinner on the ground. Mac users may want to look at Apple’s own Studio Display, which offers 5K resolution and more svelte styling than the Dell. It costs about the same, though, and is more integrated with Apple’s own styling. 

If 4K will do then we rate the DELL U2723QE as the best 4K monitor for most people and the LG 27GP950-B as the best 4K monitor overall, as the latter also has a higher refresh rate which is more suitable for gaming. 

Richard Baguley

Richard Baguley has been writing about technology since the 1990s, when he left a promising career in high finance to work on Amiga Format magazine for Future. It has been downhill for him ever since, writing for publications such as PC World, Wired and He has tested gadgets as diverse as 3D printers to washing machines. For T3, he covers laptops, smartphones, and many other topics. He lives near Boston in the USA with his wife, one dog, and an indeterminate number of cats.