The high resolution of 4K gaming monitors is great for fidelity, but when it comes to getting a next-level visual experience, that high resolution plays second fiddle to a proper HDR implementation. Unfortunately, a great many gaming monitors deliver paltry HDR with limited contrast, low peak brightness, and awful dimming zone implementations (if any) that really fail to make visuals pop. The Cooler Master Tempest GP27U isn’t one of them. This is a 4K/160Hz gaming monitor packing in serious MiniLED local dimming for $1000. While it isn’t cheap, it’s also not trying to skate by with sub-par specs.
Cooler Master Tempest GP27U – Photos
Cooler Master Tempest GP27U – Design and Features
The Cooler Master Tempest is a subtle machine. The panel section isn’t terribly gregarious, with just a few accent lights and a couple stylish cutaways. Meanwhile the stand is a simple, vertical pole stemming from a hexagonal base shaped like the Cooler Master logo. A simple cable tie comes conveniently attached to the stand.Though the style of the stand is simple, it offers plenty of adjustments and is very stable.
The monitor is rather fully featured, though, boasting an assortment of ports that should keep just about anyone happy. A pair of HDMI 2.1 ports can handle 4K/120Hz, perfect for consoles. A DisplayPort 1.4 port is ready to handle the 4K/160Hz signal. And there’s a USB-C port ready to handle display data, USB data, and 90W power delivery. Tack on a two-port USB hub, and you really can’t ask for much more.
Around the back, there’s also a single joystick that handles all the controls for the monitor. Power, settings, and all are managed through this joystick. I’ll call out a particular nuisance that comes from this, as the monitor seems to have issues with waking up with my computer whenever it goes idle, and would lock itself into a power-saving mode and fail to detect any input. While it was in this mode, the joystick was consistently unresponsive, not allowing me to access settings, change inputs, or power cycle the monitor. This led to the tedious process of unplugging and replugging both the power cable and DisplayPort cable in the back of the monitor. Your mileage may vary.
Those who love a tidy desk setup aren’t going to love that the monitor uses an external power brick, and it’s not a small one either given its 240-watt rating. All that power comes with a bit of heat, too. I noticed the heat most when fiddling with the joystick and found the bottom corners to be a particular hotspot, reaching as high as 120 degrees Fahrenheit.
Heat is par of the course though, as the monitor is offering up some serious performance. 4K at 160Hz is already demanding, but the Tempest’s ability to pair that with extreme brightness all but demands a lot of power.
While the Tempest supports both local dimming and variable refresh rates, it launched without the ability to run both at the same time. A firmware update has fixed this issue, and applying the update is fairly simple using a USB drive and one of the ports on the back of the monitor.
The monitor includes speakers, but they’re the typical last-resort style. You’ll be able to hear what you’re listening to in a quiet room, but you won’t want to watch movies, listen to music, or play games while relying on them.
Cooler Master Tempest GP27U – Testing
The Cooler Master Tempest GP27U is a color king, with its out-of-the-box settings seeing it land complete coverage of the sRGB and Adobe RGB color spaces with 98% coverage of DCI-P3 and 97% of NTSC to boot. It backs that up with impeccable accuracy that sees every color maintaining an accurate dE of less than 1.51, pulling off an average accuracy dE of 0.73 – essentially, you’d have to be a machine to see any inaccuracies.
That said, out-of-the-box performance isn’t the entire picture. This setting leaves a lot out of the picture. Brightness caps at 254.8 nits, and contrast is a paltry 850:1. That’s because the shipped defaults have the brightness set to just 35% and leave the monitor’s flagship local dimming turned off. Just dialing the brightness up to 100% and maxing out the local dimming setting, the monitor is able to leap up to a blinding 875.7-nit peak breakness and deliver a 2930:1 contrast ratio. That contrast performance is with dark areas on the screen the same time as other chunks of searing bright white. The local dimming actually allows the black areas to go even further into darkness if they’re farther removed from bright areas of the display, even offering a measure 33,070:1 contrast ratio between a screen nearly full of white hitting 932.6 nits and a nearly full black screen dropping to just 0.03 nits. This setting hurts gamut and accuracy a little, but none of the color spaces drop below 97% coverage, and accuracy is still kept below an average dE of 3.
Alas, HDR spoils the show a bit. Enabling it counterintuitively reduces the display’s color gamut, lowering AdobeRGB coverage to 79%, DCI-P3 coverage to 81%, and NTSC to 74%. Similarly, color accuracy suffers, dropping to an average dE of 2.46. That’s still quite good, but SDR color accuracy was just amazing. HDR has its perks though. I was able to measure a peak brightness of 958 nits, which could apply to a fairly small section of the screen or even a large swathe of it.
Curiously, I could never get the monitor to display its rated peak brightness of 1200 nits. The highest measurement I ever saw was 958 nits, which was achievable in a 9% to 25% window. It seemed smaller windows wouldn’t muster up enough brightness from the backlights to hit the same peak, and larger windows perhaps didn’t have enough power to drive all those pixels at that brightness level.
The Cooler Master Tempest GP27U’s local dimming proves quite effective when enabled, dramatically improving contrast, but some noticeable blooming still crops up around the local dimming zones despite there being a staggering 576 zones. Highlights on a black background see localized blooming in the area. And the edges between bright content and a black background also see blooming, though this is harder to spot. Local dimming can have some unpleasant effects around text on a gray background, as varying brightness in the screen space surrounding that area can shift the contrast between the text and background
Impressively, motion performance is quite strong on the Cooler Master Tempest GP27U. In Blurbusters UFO test, only a faint ghosting trail is present behind the UFO. Some of the UFO’s details are harder to make out in motion, but it doesn’t feel extremely blurry. There’s also no sign of pixel overshoot either. That performance was available with out-of-the-box overdrive settings. A few manual tweaks to overdrive allowed me to cut down on ghosting even more, though going too far introduced some overshoot.
Cooler Master Tempest GP27U – Gaming
While there was plenty to love from objective measurements alone, the Tempest is even better when using it for what it’s intended: gaming.
To lay it out simply, using HDR with local dimming on this monitor rocks for entertainment. Visual inconsistencies are more noticeable while trying to work and browse the internet with the monitor while HDR and local dimming are turned on, but it’s as simple as turning them back off until it’s entertainment time.
In certain situations, the Tempest GP27U’s performance can almost compare to OLED with large areas of black sinking into perceptually pitch black while highlights scream out at the monitor’s peak brightness. I even watched one of LG’s OLED TV demo videos and was largely stunned by just how good this monitor could present it. Having recently tested out an OLED monitor for Asus, I’m really impressed by how close Cooler Master manages to get, especially since OLED has its own eccentricities to deal with.
There are certain cases where the monitor shows the weakness of its local dimming zones beside an OLED panel. For instance, when displaying small highlights on a black background, which will then see blooming in the area around the highlight. This is especially noticeable when the highlights are moving, as the blooming pops in and out as one zone goes dark and another zone lights up.
The faults of the Tempest GP27U turn into little more than peccadillos when putting it to task in games. The fact that it isn’t perfectly color accurate in HDR hardly holds it back from delivering lush game visuals. The blooming from local dimming noticeable on starfield-style visuals is hardly a distraction in a frantic firefight in Warzone 2.0. And the inability to achieve a full screen shining at 1,200 nits doesn’t stop a smaller highlight from searing my eyes, especially when it’s contrasting with the rich darkness the monitor can provide.
Its fast refresh rate and respectable pixel response time let me keep up with the action in Overwatch 2 and Warzone 2.0. Meanwhile, the rich contrast and poppy HDR work great to accentuate the grimy environments of Warhammer 40,000: Darktide.
I can fairly confidently say that there are only a couple other monitors I’ve tested that could compare with this display: the Alienware AW3423DW and the Asus ROG Swift PG42UQ. Both employ OLED technology (QD-OLED in the case of the Alienware), and both cost more. Each of these three monitors has its own advantages over the others, and picking one would come down to your priorities. But the Tempest GP27U is certainly delivering a high-class experience. It’s biggest threats are likely LG’s inbound 1440p/240Hz OLED gaming monitor and Cooler Master’s own GP27Q, a near-identical monitor to the GP27U that swaps for a slightly faster 1440p panel and cuts the price down to a very tempting $499.
The Cooler Master Tempest GP27U is an exceptional monitor in most regards. It’s brilliantly colorful and stunningly bright, and it even has contrast that can rival OLEDs in some scenarios thanks to its dense MiniLED backlights and local dimming. It comes at a high price, but so does every monitor that can compare to it. The biggest thing undercutting it is the 1440p/165Hz version that’s otherwise identical but costs substantially less.