Acer Predator XB321HK Gaming Monitor Review

Why you can trust Tom's Guide Our writers and editors spend hours analyzing and reviewing products, services, and apps to help find what's best for you. Find out more about how we test, analyze, and rate.

Gaming at 4K often comes at the cost of smoothness, but Acer's hoping to make that trade-off a thing of the past. The company's Predator XB321HK gaming monitor backs up its ultra-HD resolution with Nvidia G-Sync technology, allowing you to play your 4K games without worrying about stutters or screen tears.

Naturally, that premium experience comes at a premium price, at $1,299. While it's not for everyone, the Predator XB321HK's gorgeous picture quality and handy feature-set offer a lot to love for those who play on high-end, Nvidia-powered PCs.


At a whopping 32 inches, Acer's 4K display straddles the line between small TV and huge monitor. However, it's unquestionably a gaming peripheral, sporting the charcoal chassis and deep-red highlights that define all of Acer's extra-aggressive Predator products. I was immediately drawn to the Predator's otherworldly looking base, which features two long, red, metal legs that look like they're anchoring an alien spaceship.

As far as articulation goes, you can tilt the Predator's display 25 degrees backward or 5 degrees forward, as well as raise it up or down about 5 inches. Unfortunately, you can't swivel the monitor left to right. The Predator is wall-mountable, so long as you've got a VESA-compliant mount.

Photo: Acer

Photo: Acer

You should also set the XB321HK up somewhere you plan on keeping it for a while. At close to 25 pounds, it's not the most fun monitor to lug from room to room.

Ports and Interface

The Predator sticks to the essentials, offering HDMI and DisplayPort connections (you'll need the latter for G-Sync). There are two USB 3.0 ports on the left edge for quickly plugging in your peripherals, as well as an additional two USB 3.0 ports and a USB 3.0 Type B port in the back.

MORE: Our Favorite Gaming Keyboards

I'm a big fan of physical navigation keys on monitors, so I was pleased with how easy it was to navigate the Predator's menus. Each of the monitor's five tactile buttons corresponds to different menus, allowing you to activate Game Mode, change volume, switch inputs and overclock the refresh rate in a few quick taps. There's also a robust main menu for adjusting color and brightness, as well as for activating special features such as dark boost and aim assist.

Gaming Performance

If you think 4K gaming monitors are excessive or unnecessary, you probably haven't played Star Wars Battlefront on one of these screens. EA's Star Wars shooter was a stunning showpiece for the Predator's 4K capabilities, allowing me to see each individual speck of snow that landed on my blaster as I hunted Rebel soldiers on Hoth. Colors looked vibrant and accurate, particularly whenever the virtual sun was setting.

Photo: Acer

Photo: Acer

The Predator was just as impressive when displaying the more tactical action of Rainbow Six Siege, as I was able to sneak through corridors and take out terrorists without worrying about input lag.

EA's Star Wars shooter was a stunning showpiece for the Predator's 4K capabilities.

Speaking of input lag, few genres are as dependent on latency as are fighting games. Fortunately, I was able to consistently pull off some of my most complex combos in Street Fighter V on Acer's monitor. Once I stopped to stare at the hectic Hong Kong street in the background, I was treated to sharp details and rich colors.

G-Sync Performance

The Predator XB321HK supports Nvidia G-Sync, which syncs your monitor to your graphics card for extra-smooth performance. The feature certainly came in handy during my testing; I noticed a bit of screen tearing when rapidly moving my aim or walking up stairs in games such as Battlefront and Siege, but those problems were generally all smoothed out when G-Sync was on.

Brightness, Color and Latency

The Predator is one of the brightest 4K monitors we've reviewed, registering a whopping 295 nits during our tests. That vastly outshines the ViewSonic XG2700-4K (101.32 nits) as well as our 230-nit gaming monitor average.

Photo: Acer

Photo: Acer

Acer's monitor also fared well in terms of color, with a Delta-E color-accuracy score of 2.64 (closer to zero is better). The XB321HK isn't quite as accurate as the ViewSonic (1.2), but still tops our 4.4 average. The XB321HK reproduced a strong 108 percent of the sRGB color gamut, surpassing the ViewSonic's 93.55 as well as our 103 percent average.

MORE: Our Favorite Gaming Mice for Every Genre

The Predator is also one of the lowest-latency monitors we've tested, registering just 9.6 milliseconds of lag. That beats the ViewSonic's 11.1 ms and our 13.6-ms average.

Modes and Features

In addition to looking great, the Predator offers a handful of extra bells and whistles to aid you in battle.

If you need some extra help in shooters, you can overlay the display with one of three different crosshairs. I found this feature to be fairly helpful, as the Predator's overlays synced up perfectly with the in-game interfaces of titles such as Star Wars Battlefront and Rainbow Six Siege.

The Predator's built-in speakers filled our testing lab with booming blaster sounds.

Other features include an on-screen refresh-rate ticker, as well as a black enhancer, which lets you lighten dark areas of the game, so you can find enemies more easily.

Once you've found the perfect mix of extra features as well as brightness and color settings, you can save them to one of three different custom profile slots. This lets you pull up your preferred settings in a few taps, rather than spending minutes wading through menus.


The Predator's built-in speakers are impressively crisp and loud, filling our 15 x 15-foot testing lab with the booming blaster sounds and epic orchestral scores of Star Wars Battlefront. Finer details such as footsteps were easy to hear, and punches, kicks and explosions were a joy to listen to.

Bottom Line

Not everyone needs a $1,299 gaming monitor, but the Acer Predator XB321HK gives you a whole lot for its premium price. This 32-inch, 4K display is as gorgeous and responsive as it is massive, with Nvidia G-Sync support for extra-smooth gaming. The monitor's customizable profiles and extra features are neat, and its built-in speakers are surprisingly rich.

MORE: The Best Gaming Desktops Available Now

If you're not willing to drop over a grand for a monitor and you have a rig with AMD graphics, ViewSonic's $649 XG2700-4K is a strong alternative that sells at half the price. Acer's 28-inch XB280HK ($703 on Amazon) also packs 4K and G-Sync, but lacks built-in audio as well as many of the Predator's gaming-centric features. Overall, if you game on an Nvidia card and are looking for the smoothest, biggest 4K monitor out there, the Predator is well worth the price.

Michael Andronico

Mike Andronico is Senior Writer at CNNUnderscored. He was formerly Managing Editor at Tom's Guide, where he wrote extensively on gaming, as well as running the show on the news front. When not at work, you can usually catch him playing Street Fighter, devouring Twitch streams and trying to convince people that Hawkeye is the best Avenger.