HDMI 2.1+ Cable Test — Facts and Myths

Few tech accessories generate as much debate as high-performance HDMI cables. With promises of "4K 120Hz lossless" and prices ranging from R$40 to R$800 for the same length, the market is rife with misinformation. We tested 12 HDMI 2.1+ cables from different brands and price ranges to separate fact from myth and help consumers make an informed choice.

What Actually Matters Technically

HDMI 2.1 supports up to 48 Gbps of bandwidth, required to transmit 4K at 120Hz with HDR or 8K at 60Hz without compression. For a cable to reliably transmit these signals, it needs quality conductors, adequate shielding, and connectors that maintain firm contact. What doesn't matter is whether the cable is gold-plated, has "oxygen-free crystal" wire, or has a box showing render collisions.

In our tests with a 4K 120Hz HDR source and a reference display, six of the eight certified HDMI 2.1 cables tested transmitted the signal correctly at distances of up to 3 meters — including the cheapest ones, starting at R$45. Of the two that failed, both were non-certified cables sold with HDMI 2.1 compatibility claims. The two premium cables above R$300 showed no measurable difference compared to the certified R$50 cables.

What to Buy and What to Avoid

The only variable that justifies extra spending on HDMI cables is length: above 5 meters, signal attenuation starts to be relevant and cables with superior build quality or active solutions (with built-in repeater) make a real difference. For distances up to 3 meters, any cable with official HDMI 2.1 certification (verify the QR code on the HDMI Forum website) is sufficient for any home use. The final advice: look for the certification, ignore the marketing.