What HDMI 2.1 Actually Changes for PS5 and Xbox Gaming

Every current console supports HDMI 2.1. But "supports it" and "you're getting the benefit" are different claims.

4K at 120fps

Real, but it requires the console, an Ultra High Speed HDMI cable, and a display all rated for full 48Gbps HDMI 2.1. A pre-2021 "4K TV" bought before HDMI 2.1 displays were common will likely cap you well below the console's real output.

Variable Refresh Rate (VRR)

Arguably more useful than the 120fps headline. VRR matches the display's refresh rate to the console's real-time output, eliminating screen tearing in games whose frame rate fluctuates — which is most games.

Auto Low Latency Mode (ALLM)

Automatically switches a compatible TV into its lowest-latency mode when it detects a console, removing extra processing delay without manual settings.

Where people get this wrong

The Xbox Series S targets 1440p but still supports 120fps and VRR over HDMI 2.1 — buying a premium 4K/120 TV specifically for a Series S wastes money on the resolution axis, though VRR and low-latency benefits still apply.

Practical buying rule

Check your TV's actual HDMI port spec, not just the box marketing — many TVs have only one HDMI 2.1-capable port among several HDMI 2.0 ports. Buy a certified "Ultra High Speed HDMI Cable," not an older high-speed cable that will bottleneck the connection.