Cooler MasterTempest GP27U 27" 4K UHD 3840 x 2160 Quantum Dot MiniLED Gaming Monitor, HDR1000 Ready, FreeSync/G-Sync, 160Hz, 1ms Response, 98% DCI-P3, VESA Mounting Tilt & Swivel Adjustment

I purchased a few 4k gaming monitors and this one clearly outshined the others. The HDR gaming picture is incredible and the colours are very bright.There were some firmware issues early on but those have all been resolved.There are issues with local dimming on HDR if you're working. I noticed heavy blooming using VS Code in dark mode. I use SDR mode for productivity, and HDR for gaming.I have a 27" Asus TUF 1080p gaming monitor I use as a second monitor and the text looks so grainy compared to how smooth the text is on this monitor your think the 1080 monitor had some kind of issue.IMO This is the best 27" 4k gaming monitor on the market right now.

Will be updating this review in a few months, positive or negative.Positives - INNOCOOL / CM was great to deal with. I had an issue with my order and they stayed in contact with me the whole time until it was resolved. - Amazon CS created the mess in the first place, promising that XYZ was going to happen multiple steps along the way. They were wrong every time, again luckily the 3rd party stepped in and took care of it. - Display - It looks great! i'd compare getting a "true" HDR10 display coming from SDR alienware UW like DVD > BluRay. - HDR - HDR10 movies are incredible, HDR native games are incredible, Auto-HDR is pretty cool and W11 native hdr is kind of annoying and inconsistent. Not CM's fault though. (tip win/alt/b = turn on and off HDR) - Price - I think the price is perfect and even a bit lower than it should be for the quality of the display. I have 0 dead pixels, and the refresh testing came out great. - Color Calibration - This monitor comes with color calibration straight out of the box, included is a print out of the results too. Great touch IMO.Negatives - This monitor is getting a firmware update in early/mid November. Via a CM rep on reddit... my 5 star rating is under the assumption that the below will be fixed. - You currently can not enable local dimming & async. Refer to the above on it though, I'm not too worried.

HDR with local dimming looks excellent, if not a little over saturated. Others are correct that while in this mode the whites are overpower In a way that’s almost painful to look at. But SDR looks good. I had no dead pixels or backlight bleed. A firmware update is desperately needed. But, in the meantime I feel this was a good purchase - especially at the recently reduced price of $800.UPDATE: since this review, one monitor failed and warrantied. Now at 2 dead monitors. Both failed backlights. Those aside, it seems to have issues with detecting signal and takes sometimes minutes to show an image. This is with updates to the monitor.

The display itself is gorgeous. DisplayCal is showing me high-90s for P3 and Adobe RGB coverage (and way, way above those for volume). Used as an SDR monitor with the backlight off, no complaints.BUT ... there are a number of issues that are hopefully addressable in firmware.* Enabling local dimming with SDR mode is possible, but looks horrible on the desktop and in static images. Mid-tones are bright but with low contrast. Brights are so bright they can be eye-searing, and can seemingly clip whites. I'd been hoping for it basically just to boost contrast, with real blacks when using SDR with dimming, but right now, that's a no-go. The same combo does, however, seem to look much better while gaming, especially in a game with a lot of neon lights and high contrast, like Stray. UPDATE: Taking contrast way down helps this considerably. With contrast down to about 20 (from a default of 70) and local dimming set to high, SDR content looks similar to how it does with dimming off and contrast on 70, only blacks are way deeper (which is a good thing).* Enabling HDR disables Adaptive Sync. You can only get dimming and adaptive sync enabled if you enable dimming first, because it greys out the sync control. And sometimes weird things happen -- like if you have HDR disabled in the monitor and enable sync, the screen blanks out for a second, then Windows 11 comes back with HDR enabled (while it's still disabled in the monitor itself), looking horrible because dimming is still disabled. That's at least easily fixed by disabling hdr in windows from there.* The KVM and input select are both handy, but don't have an option to be tied together (see how they work on Gigabyte monitors -- it's great). That doesn't work very well if you have multiple devices plugged in and one goes to sleep. You try to switch from one device (say, a PC), to a second device (say, a Macbook), and the Macbook isn't outputting a signal, so it switches back to the PC. If you think to switch the KVM FIRST to the macbook, you can start hitting the spacebar or wiggle the mouse to get the Macbook to wake up. And if there's no PC awake on the first input but the KVM is still set to the PC? You can't get into the OSD without the computer first finding a signal and showing SOMETHING, so you can't switch the KVM ...* HDR looks very good. SDR content and the UI with HDR enabled in Windows is ... OK. That's more about Windows than the monitor. But the monitor has a noticeable green tint in the HDR setting, with no color control. Grey uniformity is noticeably uneven and there's some flickering when HDR and dimming are enabled, too, which makes that tough to leave on all the time.I'm looking forward to a firmware update a CM rep has promised on reddit, to allow adaptive sync to work with HDR, and to enable color control in HDR. Then I can use SDR mode with dimming off most of the time, and switch selectively into HDR mode for HDR content. I'd love to be able to just leave HDR enabled all the time (like, say, on my macbook's built-in screen, or like works well on OLED screens) but that doesn't seem to be in the cards unless MAYBE CM reworks the dimming algorithm to be less brutal in SDR mode.

** Update 25-Nov-2022 ** The promised firmware update has been released on the CoolerMaster website. Had to copy MERGE.bin to root folder of a USB flash disk formatted as FAT32 with Master Boot Record (MBR). Firmware update will take a good 5 minutes or so; just need to be patient. Picture quality is significantly improved with local dimming enabled. When moving bright objects around the screen, some local dimming artifacts (such as full screen brightness fluctuations) have disappeared. Haven't tested VRR with local dimming, but the capability is there. Improvements also made to KVM.I've been waiting for a high refresh rate 4K monitor with mini-LED for a long time. Even Apple's recent Studio Display lacks high refresh rate and mini-LED, yet sells for $1599 -- and contains a single video input.By comparison, the Tempest GP27U is packed with all the latest features. Four inputs including one with USB-C (w/90W charging), 160Hz variable rate refresh, mini-LED, quantum dot, IPS panel, HDR, high-accuracy color, speakers, USB ports, etc.And the price? Currently $799, which is $800 cheaper than Apple's -- in other words, HALF the price.I'll provide early impressions now and will update this review as my experience with it builds over the next few weeks. I'm not a gamer so my impressions are based only on productivity applications.I'm using a Mac with two monitors side-by-side: (a) this monitor and (b) Asus 4K 60Hz Designo.This monitor is advertised not only for gaming, but also for productivity workflows because of high black levels with mini-LED, accurate color, and high refresh rate (for smooth movement of windows).Day 1 Impressions:1. Zero dead pixels. No manufacturing defects of any kind.2. Monitor is preset to a particularly bright, non-miniLED mode, with too high contrast. It takes a few minutes to experiment with different preset picture modes and discrete picture settings. Reducing contrast to 50%, enabling mini-LED, lowering brightness, and changing the color temperature to 'standard' were some of the adjustments I made right away.3. Because the Asus 4K Designo is sitting right next to the Tempest G27U, I can make A/B comparisons rather easily. In every color mode the Tempest has punchier, more vivid colors. In dark scenes, not only are the blacks noticeably darker (i.e. blacks are black, not gray), but colors ring through as if HDR were enabled. (HDR is disabled.)4. Text legibility seems a little off compared with the Asus, but I think a little more tweaking with picture controls should help. Specifically, text appears a little 'thinner' than on the Asus. Each stroke is thinner. **UPDATE** Reducing Sharpness to 50% has fixed this issue.5. Asus 4K Designo has speakers designed by Bang and Olufsen. For built-in speakers, they are pretty decent. The Tempest's speakers easily lose the contest, but for me, having speakers in the monitor is better than not having them. I'll switch to headphones or desktop speakers whenever I need to, but most of the time it's very convenient to use the monitor's speakers for all the little sounds that macOS makes.6. Mini-LED makes a huge difference. Blacks are black. It is incredibly refreshing to get rid of the backlight bleed that plagues every standard backlit monitor. I remember the day my Asus 4K Designo arrived. I was so excited to set it up, only to have the grin wiped off my face when the boot screen popped up with the entire background smeared in dark gray. That is the main problem this monitor fixes for me.7. High refresh rate. My current GPU does not support VRR, so I'll update this item soon -- after switching to a newer card. I often drag large windows across the screen, and know the difference that high refresh rate makes on my 144Hz 1440p monitor.** UPDATE #1 ** While waiting for the new video card to arrive, I decided to connect my Apple 14" MacBook Pro (Apple Silicon) to the monitor's USB-C port. The MacBook Pro immediately set it to 144Hz. This monitor is a very good match for the 14- and 16-inch Apple Silicon MacBook Pros because:* Both have Mini-LED screens* MBP has 120Hz ProMotion and Tempest GP27U has up to 160Hz VRR* Note: MPB does not support VRR so it sets GP27U to fixed 144Hz, which is fine (see photo)* The GP27U is therefore an ideal external monitor for the MBP's built-in display (they are very well matched)Summary:Pros:1. Full feature set. It there anything else that compares to this?2. Mini-LED make a huge difference.3. Colors are rich and vibrant.4. Price -- especially when compared to Apple Studio Display (it is half the price of Studio Display)5. Firmware is upgradeable via USB6. Fully adjustable (height, swivel, tilt, VESA mount)Cons:1. Out-of-box picture settings are not ideal. It will take some time to tweak them. Mini-LED is disabled by default so you'll see gray background.2. Text appears a little thin. Need to tweak settings further. **UPDATE** Fixed by reducing Sharpness to 50%.3. Speakers are okay, but I would rather have them than not.4. This would be a home run at 5K resolutionCurrent Picture Settings:Picture Mode: StandardBrightness: 50 ---> **UPDATE** changed to 25Contrast: 60 ---> **UPDATE** changed to 52Black Stabilization: 50 ---> **UPDATE ** changed to 45Sharpness: 50Current Color Adjust Settings:Color Temperature: Cool ---> **UPDATE** Changed to 'Blueish'Gamma: 2.2 ---> **UPDATE** Changed to 1.8Color Domain: AutoColor Space: AutoBlue Light Filter: 0Current Advanced Settings:HDR: OffLocal Dimming: LowHDMI Range: AutoRGB Light: Off (LEDs on rear of monitor)