Dell UltraSharp U3425WE

This is what matters about Dell UltraSharp U3425WE.

About

The smaller 3440x1440 sibling of the U4025QW — its HDMI port is stuck on the older TMDS signaling scheme despite an HDMI 2.1 label, choking the panel's true 120Hz ceiling down to 100Hz.

HDMI version
2.1
DisplayPort version
1.4
Max resolution
3440x1440@120Hz
Requires DisplayLink driver
No

Ports: 1× HDMI 2.1, 1× DisplayPort 1.4, 1× Thunderbolt 4 (upstream), 1× Thunderbolt 4 (downstream), 1× USB-C (upstream), 2× USB-C (downstream), 4× USB-A, 1× Ethernet (RJ45) and 1× Audio line-out 3.5mm

Confirmed with

  • Notebook (generic)

    Despite an HDMI 2.1 badge, the port uses legacy TMDS signaling rather than the modern FRL scheme, choking the panel's true 120Hz ceiling down to 100Hz over HDMI — reaching the full refresh rate requires DisplayPort or a Thunderbolt/USB-C connection instead.