Compatibility information for Intel® Iris® Xe Graphics and ultrawide displays using Dell.
Trying to get 2560x1080 resolution on a Dell Ultrawide Monitor, but it's not in the list.
Intel® Iris® Xe Graphics can support ultrawide display resolutions using DisplayPort (DP) 1.2 connections or newer. However, the resolution on External Monitor is Limited to 1920 x 1080 or 1900 x1200 Using HDMI. You may refer to Dell Article Number: 000126548
.