Review on Cooler Master Tempest GP27U: High Refresh Rate, Swivel Adjustment, Adaptive Sync, IPS Display by Eric Galvin

The display itself is awesome. DisplayCal shows me high 90's for P3 and Adobe RGB coverage (and much higher than for volume). Used as an SDR monitor with the backlight off, no complaints. BUT. There are a number of issues that we hope will be fixed in the firmware. * Enabling local dimming in SDR mode is possible but looks terrible on desktop and in static images. The midtones are bright but lack contrast. Light colors are so bright that they can blind the eyes and appear to cut off white. I was hoping this would mainly just increase contrast, with true blacks when using dimmed SDR, but that's currently not possible. However, the same combination looks much better in gaming, especially in a neon-heavy, high-contrast game like Stray. UPDATE: Lowering the contrast helps a lot with this. With Contrast reduced to around 20 (default 70) and Local Dimming set high, SDR content looks the same as with Dimming off and Contrast set to 70, only the blacks are much deeper (which is a good thing)*. Enabling HDR disables Adaptive Sync. You can only enable dimming and adaptive sync if you enable dimming first, as this will dim the timing. And sometimes strange things happen - for example, if you disable HDR on a monitor and enable sync, the screen goes blank for a second, then Windows 11 comes back with HDR enabled (although it's still disabled on the monitor itself) and looks terrible because the dimming is still disabled. At least it's easy to fix by disabling HDR in Windows from there. * KVM and input select are handy but can't be tied together (see how they work on Gigabyte monitors - it's awesome). This doesn't work well if you have multiple devices connected and one of them goes to sleep. You try to switch from one device (e.g. PC) to another device (e.g. Macbook) and the Macbook doesn't output any signal so it switches back to PC. If you want to switch KVM to MacBook FIRST, you can press spacebar or move mouse to wake up MacBook. What if the PC isn't active when you first log in, but KVM is still configured on the PC? You can't get into the OSD without the computer first finding the signal and displaying SOMETHING so you can't toggle KVM. * HDR looks very good. SDR content and HDR-enabled UI on Windows are . WELL. It's more about Windows than the monitor. But the monitor has a distinct green cast in HDR settings without color adjustment. Gray uniformity is noticeably uneven, and there's also some flickering when HDR is on and dimmed, making it difficult to keep it on all the time. I look forward to the firmware update promised by the CM rep on Reddit to enable adaptive syncing. to work with HDR and enable color management in HDR. I can then use SDR mode with dimming disabled most of the time and selectively switch to HDR mode for HDR content. I'd love to keep HDR on at all times (on my MacBook's built-in screen, for example, or it works well on OLED screens, for example), but that doesn't seem to be in the cards, unless maybe CM revises the dimming algorithm to allow for that it was less violent in SDR mode.