KYY X90D Triple Portable Monitor Review: A screaming dual-screen bargain at $250

It’s been a year since we looked at KYY’s X90A portable monitor, but the company is back with a new variant called the X90D. The X90D seems strikingly similar to its elder sibling, but has slightly larger display panels, each measuring 15.6 inches across.

The resolution stays the same at 1920 x 1080, and KYY includes what we loved about the original: the integrated kickstand and multiple operating modes to suit your needs. Even better, the X90D is available for well below the $400 price of the X90A we reviewed in early 2024. Does the X90D now allow KYY to strike it big on the list of the best portable monitors? Read on to find out.

Design of the KYY X90D Triple Portable Monitor

The KYY X90D looks just like the X90A, albeit with slightly larger display panels (15.6 inches versus 14 inches). The similarities pay off regarding build quality, as this is a solid, well-built unit with a chassis made entirely of aluminum. It's also hefty, weighing 3.2 pounds, but that’s the price you must pay to lug around two 15.6-inch display panels and the accompanying hardware.

The X90D’s displays both feature a 360-degree hinge. In the Extended mode, both displays flank your laptop's built-in display. You can adjust the hinge to achieve your desired viewing angle for both. In Presentation mode, you can swing both displays backward to share your screens with people sitting across from you.

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

There are also in-between modes, which make use of only one panel. Depending on how you position the stand and/or built-in kickstand, you can use just one display mounted horizontally or vertically.

The kickstand is also constructed of aluminum and features a stiff hinge. It can support the full weight of the X90D and is highly adjustable to achieve an ideal viewing angle with the dual displays.

According to KYY, the X90D is optimized to work with 12- to 16-inch laptops. I primarily used the X90D with a 14-inch MacBook Pro, which nestled perfectly between the twin panels. In addition, the black finish of the X90D nearly matched the Space Black of my laptop.

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

(Image credit: Tom's Hardware)

Each display panel has a set of controls on the bottom bezel. The right display panel features +/-, Menu, and Power buttons, while the left panel features +/- and Menu. There are also only two ports on the monitor, both USB-C.

The X90D will connect with laptops that support Thunderbolt or USB-C with DisplayPort Alt-Mode. If your laptop provides enough juice, the X90D will operate with a single USB-C cable. However, if you need auxiliary power, KYY wisely includes an additional USB-C to USB-A cable and a USB-A wall adapter in the box.

Unfortunately, unlike the Limink LK14, the X90D doesn’t come with a case or screen protectors. This makes transporting the portable monitor, with its rotating screens just dangling loosely in space when stowed, highly susceptible to damage. I would gladly pay an extra $5 or $10 to get a decent carrying case specifically designed for the X90D in the box from the factory.

KYY X90D Triple Portable Monitor Specifications

Connecting the KYY X90D Triple Portable Monitor

Given the lack of HDMI ports on the X90D, you're out of luck if your laptop lacks Thunderbolt ports or support for DisplayPort Alt-Mode over USB-C. This is disappointing for users with older laptops or anyone with a Raspberry Pi who wants to partake in some dual-screen action.

However, since my MacBook Pro has three Thunderbolt 4 ports, it was fully equipped to accommodate the X90D. Better yet, the MacBook Pro can power the X90D with a single cable, which cuts down on the cable clutter that can sometimes arise with competing dual-screen portable monitor solutions.

I'm used to just plugging in a monitor and it being instantly recognized by the operating system. That wasn't the case here. I plugged the X90D into my MacBook Pro, and it powered on. Then, it gave me "No Signal" warnings on both displays. It next showed, "Entering Low Power Mode" and then shut down. In my haste, I hadn't bothered to look at the quick start guide, which said I first needed to install a display driver for the monitor. Luckily, KYY provides a thumb drive that has both USB-A and USB-C connectors for universal support. I plugged the thumb drive in, selected the version of the driver that supports macOS Sequoia, and installed it on my system.

At that point, I plugged the X90D's USB-C cable back into the MacBook Pro and both displays fired up as expected. MacOS Sequoia defaulted to extend my desktop on the right display and mirror my laptop's internal display on the left display. After navigating to display settings and flipping a couple of switches, I had the X90D operating as an extended display on both panels, expanding my workspace on either side of my MacBook Pro's internal display.

OSD on the KYY X90D Triple Portable Monitor

Each display on the X90D has its own on-screen display (OSD) and set of controls for navigation. This can come in handy, as you can choose from five preset display modes: Standard, Game, Movie, Photo, and Vivid. If you want to devote one screen to watching a movie and one for gaming, you can dial in settings specifically to suit the needs of each.

It takes a while to become acclimated with the OSD. You first press the Menu button to bring up the OSD, then use the + or – buttons to navigate right or left. You then press the Menu button again to go deeper into a submenu. Once you’ve landed on an actionable item, you can use the +/- buttons to increase or decrease the value (i.e., brightness, contrast, black level, sharpness, etc.).

Besides the usual color and brightness settings, there are controls for the OSD time, and vertical/horizontal positioning of the OSD window. Unfortunately, KYY hasn’t fixed my main gripe with the OSD controls from the X90A. The X90D still positions the controls on the lower right corner (left display) and lower left corner (right display). That places the controls precariously close to the hinge and where your laptop meets the central spine of the X90D. It makes navigating the OSD awkward as you must angle your fingers into the narrow nook to make adjustments.

Image Quality on the KYY X90D Triple Portable Monitor

The X90D is a dual-screen IPS portable monitor, with each Full HD (1920 x 1080) display measuring 15.6 inches across. The monitor has a claimed maximum brightness of 300 nits, a contrast ratio of 1,200:1, and a 60Hz refresh rate. The display panels also have a matte finish, which helps to cut down on reflections.

According to our colorimeter testing, the X90D improved upon the X90A in color performance. In the Standard picture setting (the default mode), we measured 81.3 percent coverage of sRGB and 57.6 percent of DCI-P3. While those are appreciable gains over its predecessor, things took a step backwards regarding overall brightness.

We measured 181.4 nits maximum panel brightness for both panels on the X90D. For comparison, the X90A achieved 227.8 nits with default settings, which was already at the bottom of the class. If there's any consolation, the Game and Vivid modes boosted maximum brightness to 201.2 nits and 203.6 nits, respectively.

I noticed slightly more accurate colors, particularly in the reds and greens, compared to the disappointing performance of the elder X90A. I watched several movies with the left display while going through my daily work routine with my laptop’s internal display and the right display. The 2002 Leonardo DiCaprio flick Catch Me if You Can looked great on the monitor with its 1960’s aesthetic and bright color palette, as did the first three episodes of Marvel’s Daredevil: Born Again. My only major complaint about the monitor is regarding brightness.

With spring approaching, and daytime temperatures in the mid-70s here in the southern states, I like to spend part of the afternoon working on my back porch to get some fresh air and listen to nature. However, the displays weren’t as bright as I wanted them to be to counteract the ambient light. Of course, it’s hard to make fair comparisons when X90D is flanking the far superior (and much brighter) internal Mini-LED display on my MacBook Pro, but KYY could do better here.

Honestly, most people will likely stick to using the X90D indoors, where its brightness was more than adequate under the overhead LED lighting in my home. Whether I was watching movies, working on Word documents, or bashing around in Pixelmator Pro, the dual 1920 x 1080 displays were more than up to the task of handling those tasks.

Bottom Line

The KYY X90D is an impressive piece of kit. It has a well-built and sleek aluminum chassis, and its color performance improves upon the X90A that came before it. However, the X90D isn’t perfect – no product is. Maximum brightness regressed, and KYY still hasn’t changed the awkward positioning of the OSD controls. In addition, KYY doesn’t provide a case in the box to protect the display panels from damage when not in use.

But those foibles can be overlooked given the X90D’s price tag. When we reviewed the X90A last year, it had a street price of around $400. The X90D, with its larger displays, costs just $250 on Amazon (in black or grey). That’s a game-changer for a dual-display portable monitor of this caliber, and it’s definitely worthy of your attention if you’re in the market.