Gaming Performance

The Cooler Master Tempest GZ2711 sports a 240 Hz refresh rate WOLED panel, which supports the adaptive synchronization technology on AMD, NVIDIA, and Intel graphics cards. The adaptive synchronization range is 48–240 Hz, so that's the framerate range your PC should be able to achieve at 2560 x 1440 resolution to experience buttery smooth, screen-tear-free gameplay. For modern mid-range gaming rigs, that's not too hard of a challenge.

Response Time and Overdrive

I usually test the monitor response time with the Open Source Response Time Tool (OSRTT), developed by Andrew McDonald of TechTeamGB. It's a nifty tool that, combined with the OSRTT Launcher app, measures panel response times and presents them through detailed graphs and easy-to-read heatmaps. You can find everything you might want to know about the OSRTT in its technical documentation and on the official website, where you can order your unit, too. The OSRTT gives us three interesting heat maps to observe.

However, the OSRTT Pro tool requires constant brightness to do its magic properly, which isn't achievable on the Cooler Master Tempest GZ2711, since it's not possible to turn off the Auto Brightness Limiter. Luckily, I've tested several other monitors with the same panel, with all of them equipped with an ABL toggle, and every time I got an identical result. The average perceived pixel response time is around 0.7 milliseconds, which means that the moving object's sharpness is superb. There's no ghosting or overshoot to note at any given refresh rate; OLED panels are known for sustaining their pixel response performance regardless of the refresh rate. That comes as great news to anyone using adaptive synchronization technology, especially when playing a game where your PC struggles to maintain a stable framerate. This is an inherent characteristic of WOLED and QD-OLED gaming monitors, and that's why they measure and perform similarly in response time tests.

I also used the Aperture Grille's Smooth Frog test and a 960 FPS camera to confirm that there are no signs of visible ghosting or overshoot on the Cooler Master Tempest GZ2711.

Input Lag

To measure the input lag of a monitor, I switched from using the LDAT V2 (Latency Display Analysis Tool), which I've covered extensively in my NVIDIA Reflex review, to the OSRTT Tool. The OSRTT Tool and the accompanying software include a DirectX code developed by Andrew McDonald of TechTeamGB, which allows the OSRTT Launcher to track the events and capture the frame time, making it possible to isolate the monitor latency from other factors that come into play when using the click-to-photon testing methodology, namely the USB polling rate and game render time. For a deeper insight, I suggest you watch an excellent overview video made by Andy himself.

While I used a consistent methodology in all my previous LDAT-based monitor reviews and kept everything the same, switching to the OSRTT-based approach isolates me from potential issues, such as game engine updates (I based my tests on Overwatch, which transformed into Overwatch 2), and allows me to move on to a different testing system at will. I have to admit it was becoming increasingly annoying having to keep my old Core i9-9900K/RTX 2080 Super test system around for nothing but monitor input lag testing. Thanks to Andy for his tireless work on the OSRTT Tool and the OSRTT Launcher software!

Here's how the Cooler Master Tempest GZ2711 holds up in terms of input lag after doing 100 iterations of the input lag test.



The Cooler Master Tempest GZ2711 shows an average input lag of around 6.4 milliseconds, which is a great score for a gaming monitor. Such low input lag can't be picked up even by the most hardcore gamers, including esports professionals.