Cooler Master Tempest GP27U Review: 4K 160Hz Mini LED HDR Gaming Monitor

The Cooler Master Tempest GP27U was one of the first 27″ high refresh rate gaming monitors that had the required hardware for proper HDR image quality at a reasonable price!

Image Quality

Based on an IPS panel, the Tempest GP27U provides you with accurate, consistent and vibrant colors. First of all, you get the 178° wide viewing angles, which ensure that the image remains perfect regardless of the angle you’re looking at the screen.

Brightness, colors and gamma are consistent across the entire screen, making the display suitable for professional color-critical work right out of the box thanks to the precise Delta E < 2 factory calibration.

Further, the monitor has a very wide color gamut thanks to its quantum dot enhanced film layer, covering 99% Adobe RGB and 98% DCI-P3 color space. This makes the monitor great for various types of color work, but you also get rich and saturated colors in games and videos.

In comparison to the standard ~90% – 95% wide gamut displays, you get especially vivid blue, cyan and green colors.

In the OSD (On-Screen Display) menu, the Color Space option allows you to restrict the display’s native gamut to sRGB, Adobe RGB, DCI-P3 and BT. 2020 color space in order to avoid over-saturation beyond those gamuts. What’s more, the brightness setting is not locked in these modes!

Moving on, the 4K UHD resolution results in crystal-clear details and text, as well as plenty of screen real estate on 27″ sized displays due to the high pixel density of 163 PPI (pixels per inch). You will need to apply some scaling in order to make small text readable, but the details will remain crisp and sharp.

The Cooler Master Tempest GP27U monitor has an exceptional peak brightness of 600-nits in SDR, meaning that it can get more than bright enough even in well-lit rooms.

When viewing HDR content, you get a boost in peak brightness up to 1,200-nits for punchy highlights (up to 1,500-nits for 10% white windows), while the 576-zone mini LED FALD (full array local dimming) solution can dim parts of the image that are supposed to be dark, thus significantly increasing the monitor’s native 1,000:1 contrast ratio to over 10,000:1, depending on the scene.

As a result, you simultaneously get bright highlights, deep blacks, crisp details and vibrant colors – everything that you need for the true HDR viewing experience. Local dimming also works in SDR mode, allowing you to enjoy improved image quality in games and videos that don’t support HDR.

There are three local dimming modes: Low, Medium and High. The Medium offers the most accurate HDR image, while the High gets the brightest, so choose according to your preference.

Of course, as there are 576 zones and over 8 million pixels on the screen, in some demanding scenes (night sky, fireworks, etc), the light of small bright elements can bleed into the surrounding dimmed zones and crate blooming or the halo effect.

This is an expected drawback of this technology and luckily, it isn’t noticeable except in particularly demanding scenes, which is tolerable. An alternative is to get an OLED display with per-pixel dimming, but these panels cannot get nearly as bright and suffer from the risk of burn-in.

Also note that while the Cooler Master specifies that the Tempest GP27U is ‘DisplayHDR 1000 compatible’, it doesn’t actually appear on VESA’s list of certified products.

However, given how meaningless this certification is, it doesn’t really matter. The HDR image quality of the GP27U is drastically better than that of some HDR-1000 certified products, such as the LG 32GQ950 with 32-zone edge-lit local dimming.

Performance

The Cooler Master Tempest GP27U has six response time overdrive modes: Off, Normal, Advanced, Ultra Fast, Dynamic and User (with adjustable overdrive from 0 to 100 in increments of 1).

We recommend sticking with the Advanced setting for the best performance. It has the least amount of ghosting with only minor overshoot at high frame rates. In case you find the amount of overshoot too bothersome, you can use the User mode at 45 for a bit faster response time than ‘Normal’ with less overshoot than ‘Advanced.’

Below ~100FPS when using VRR, we recommend dialing it back to ‘Normal’ in order to prevent overshoot.

Input lag is low at ~4ms of delay, which is imperceptible. With local dimming enabled, it increases to ~14ms, so remember to disable it in competitive titles. For graphically-oriented games, most users won’t notice the added latency by local dimming.

For tear-free gameplay up to 160FPS, VRR is supported via HDMI 2.1 VRR and Adaptive-Sync over DisplayPort (AMD FreeSync Premium and NVIDIA G-SYNC Compatible).

The Cooler Master GP27U doesn’t appear on either AMD’s or NVIDIA’s list of certified products, but the VRR performance is buttery-smooth without any visual artifacts.

When using VRR and local dimming simultaneously, you might detect flickering in certain scenes or games, so you might have to disable one of the two features.

All in all, we find that the Tempest GP27U is an excellent gaming monitor despite its blooming and occasional flickering issues. The 27″ 4K 160Hz IPS panel with fast response time, VRR support, exceptional color gamut coverage, fully ergonomic stand and extensive connectivity options (KVM, USB-C) is worth $800 without even adding the 576-zone mini LED FALD backlight to the equation.

So, the fact that in some games simultaneous VRR and local dimming operation might work suboptimally is forgivable.

Note that the monitor does not support MBR (Motion Blur Reduction) even though ‘1ms MPRT’ is specified on Amazon’s product page.

The backlight of the monitor is flicker-free (unless local dimming is enabled) and there’s an integrated low-blue light filter.

Features

At the rear of the display, there’s a directional joystick for quick and easy navigation through the OSD menu.

Useful gaming features include Black Stabilization (improves visibility in dark scenes by altering the gamma curvature), various picture presets, crosshair overlays, on-screen timers and a refresh rate tracker.

Besides the standard image adjustment tools (brightness, contrast, color temperature, aspect ratio, input source selection, etc.), the Cooler Master Tempest GP27U also offers five gamma modes (from 1.8 to 2.6), sharpness and 6-axis hue/saturation settings.

Design & Connectivity

The stand of the monitor is robust and versatile with up to 110mm height adjustment, -5°/20° tilt, +/- 15° swivel, +/- 90° pivot and 100x100mm VESA mount compatibility.

Further, the screen has a light matte anti-glare coating that prevents reflections without making the image too grainy.

Connectivity options include DisplayPort 1.4 with DSC, two HDMI 2.1 ports with full 48 Gbps bandwidth, USB-C (DP 1.4 Alt Mode and 90W Power Delivery), a dual-USB 3.0 hub, two 3W integrated speakers, a headphone jack and a built-in KVM functionality.

All four display inputs support 4K 160Hz 10-bit color without any noticeable compression.

Price & Similar Monitors

The Cooler Master Tempest GP27U price amounts to $800.

We recommend checking out the Innocn 27M2V. It has a better 1152-zone mini LED FALD solution for the same price, while the Acer XV275K P3 with the same 576-zone backlight can be found on sale for just $550.

If you’re looking for a cheaper HDR monitor, check out the AOC Q27G3XMN with a 336-zone mini LED FALD backlight for ~$250.

Note that you can also find 27″ 1440p 240Hz OLED gaming monitors on sale for as low as $600.

Check out our best HDR monitors buyer’s guide for more monitors and recommendations.

Conclusion

Thanks to its IPS panel with a wide color gamut, 576-zone mini LED FALD and 4K UHD resolution, the Cooler Master GP27U offers amazing HDR image quality, while its fast response time and VRR support ensure smooth performance.

While there is some blooming noticeable in certain scenes, this is the case even with much more expensive mini LED displays too, so it’s tolerable considering the price and the nature of this technology.

However, Innocn’s model offers twice the zone count for the same price, so it will have a lot less blooming, while Acer’s version offers the same viewing experience for up to $250 less.

Specifications

Screen Size	27-inch
Resolution	3840×2160 (Ultra HD)
Panel Type	IPS
Aspect Ratio	16:9 (Widescreen)
Refresh Rate	144Hz (160Hz OC)
Response Time	0.5ms (GtG)
Adaptive-Sync	FreeSync (48-144Hz) (48-160Hz with firmware update)
Speakers	2x3W
Ports	DisplayPort 1.4, 2x HDMI 2.1, USB-C (DP 1.4 Alt Mode, 90W)
Other Ports	Headphone Jack, 2x USB 3.0
Brightness	600 cd/m²
Brightness (HDR)	1200 cd/m²
Contrast Ratio	1000:1 (static)
Colors	1.07 billion (8-bit + FRC) 99% Adobe RGB, 98% DCI-P3
HDR	DisplayHDR 1000
Local Dimming	576-zone mini LED FALD
VESA	Yes (100x100mm)