I got very lucky with this monitor. I just bought it 1 week ago and was only thinking about playing first person shooters since it's been about 6 months since I dabbled with Prepar3d. A couple days after I bought it, I naturally thought about Prepar3d and decided to see if I could get a 30hz HD mode working with this monitor. Long story short, this monitor supports 24hz and 30hz modes in both 1440p (2560x1440) and 1080p (1920x1080) by setting the minimum vertical sync rate to 20 with the CRU utility, restarting the computer, then setting a custom mode in your graphics panel. I used an HDMI cable for this and have not tried with a display port cable yet. There is one caveat to setting the custom modes (on Intel graphics at least) - You will get two entries for the mode you set. This only seems to happen for 30 and 24 hz modes. You will get a "24hz" and a "23hz" entry for 24hz or a "30hz" and a "29hz" entry for 30hz. I checked with a frametime checker and you indeed get exactly 30hz and 24hz respectively if you set these custom modes but when you set 24hz it will show the "23hz" in the control panel for some reason and it will show "29hz" when you set the 30hz mode. This is obviously a bug with Intel drivers but it works fine despite the double entries. This CRU method is hit or miss with monitors. Many monitors have a hard lock for lower limit and you cannot set 30hz and 24hz modes no matter what you do. Anyways, A very good monitor for the price and now with 30hz 1440p I feel like I hit the lottery (us flight sim fans love our 30hz mode, lol).
Monitor - https://www.google.com/search?q=acer+xg ... 0&bih=1307
CRU Utility - https://www.monitortests.com/forum/Thre ... tility-CRU
In CRU Utility, download, unzip, and open the CRU utility. Make sure you select your monitor (ACR0414 - XG270HU). Hit the "Edit" button directly to the right of your monitor name. Under "Range Limits" set the lower "V Rate" to 20 Hz. Hit the "OK" button. Hit the "OK" button again in the main window. Restart your computer. Set your custom 30hz (and 24hz) modes in your graphics panel. Done.
Note - For those of you wondering why I have Intel graphics. It's an optimus laptop with switchable graphics so all the monitor modes are set in the Intel graphics control panel.
