HDMI 2.1, eARC, and the only cable you need
Version numbers, port labels, and $80 cables make HDMI feel complicated. It comes down to two checks: the right port and a certified cable.
Do you need HDMI 2.1?
Only for gaming. HDMI 2.1 raises the ceiling from 18 Gbps to 48 Gbps, and the practical payoff is 4K at 120Hz from a PS5, Xbox Series X, or gaming PC, plus variable refresh rate and auto low-latency mode. For movies and TV, 4K at 60Hz with full HDR fits comfortably inside HDMI 2.0, so a non-gaming system doesn’t need to chase the spec. One trap to check before buying: many TVs and receivers put full-bandwidth support on only some of their ports, so confirm which port actually carries the 4K/120 feature, not just that the box says “2.1.”
What is eARC, and do you need it?
eARC (enhanced Audio Return Channel) sends audio from the TV back down a single HDMI cable to your receiver or soundbar — and unlike the older ARC, it has the bandwidth for lossless formats like Dolby TrueHD Atmos and DTS-HD Master Audio. Plain ARC tops out at compressed audio, so Atmos arrives in its lossy streaming form. If you watch from apps built into the TV or from devices plugged straight into it, connect the TV’s port labeled eARC to the receiver’s ARC/eARC output and you get full-quality audio with one cable and one remote.
Do expensive HDMI cables make a difference?
No — within a certification tier, a $12 certified cable performs identically to an $80 one. HDMI is digital, so a cable either delivers the bandwidth or visibly fails; there is no subtle picture-quality difference to pay for. What matters is the tier, because HDMI cables don’t have version numbers — they have certification tiers: “Ultra High Speed” (look for the official label with a scannable QR code) is certified for the full 48 Gbps and covers everything including 4K/120 and eARC; “Premium High Speed” handles 18 Gbps for 4K/60 HDR. The one real upgrade is length: past roughly 10 feet at full bandwidth, passive copper gets unreliable, and long or in-wall runs to a projector call for an active optical HDMI cable — just note those are directional, with marked source and display ends.