HDMI 2.1 is the video standard that quadruples bandwidth to 48 Gbps, enabling 4K at 120Hz and 8K at 60Hz with dynamic HDR and gaming features like VRR.
Getting the most from a PlayStation 5 or Xbox Series X means understanding what is HDMI 2.1 — the video standard that quadrupled bandwidth to 48 Gbps, enough for 4K at 120Hz and 8K at 60Hz with dynamic HDR. That bandwidth jump from 18 Gbps on HDMI 2.0 isn’t just a number; it unlocks features gamers and home theater enthusiasts have waited years for, including Variable Refresh Rate, Auto Low Latency Mode, and enhanced audio return.
HDMI 2.1 Specifications: Bandwidth, Resolution, and Refresh Rates
HDMI 2.1 delivers 48 Gbps of uncompressed bandwidth across four lanes running at 12 Gbit/s each, That capacity supports resolutions and frame rates that previous standards couldn’t touch.
The spec supports 4K at up to 120 Hz with full 4:4:4 chroma subsampling — no color compression. At 8K, it handles 60 Hz, and HDMI 2.1b, a minor update released in 2021, added clarifications without changing the core spec.
| Feature | HDMI 2.1 | HDMI 2.0 |
|---|---|---|
| Max Bandwidth | 48 Gbps | 18 Gbps |
| 4K Resolution | Up to 120 Hz | Up to 60 Hz |
| 8K Resolution | Up to 60 Hz | Not supported |
| HDR Type | Dynamic HDR (scene-by-scene) | Static HDR |
| VRR Support | Yes (HDMI Forum VRR + Game Mode VRR) | No |
| ALLM | Yes | No |
| eARC | Yes (Dolby Atmos, DTS:X) | Yes (older standard) |
| Cable Required | Ultra High Speed (48G) | High Speed |
Which Devices Support HDMI 2.1?
HDMI 2.1 support starts with the console and graphics card generation that launched in 2020. The PlayStation 5 and Xbox Series X both require HDMI 2.1 to output 4K at 120 Hz, and they rely on VRR and ALLM for smooth gaming. On the PC side, NVIDIA’s RTX 30-series and AMD’s RX 6000-series GPUs include HDMI 2.1 outputs capable of driving 8K displays.
TV makers adopted the spec across their high-end lines starting in 2019. LG’s OLED CX and C1 series, Samsung’s QN90A QLED, and Sony’s X90J all include full 48 Gbps ports, though some early 2019 models offered partial support capped at 4K at 60 Hz. For buyers shopping today, our roundup of the best 4K HDMI 2.1 TVs shows which models deliver the full spec.
What Cable Do You Need For HDMI 2.1?
An Ultra High Speed HDMI cable — originally called “48G” during development — is required for full 48 Gbps operation. Standard High Speed cables from the HDMI 2.0 era lack the bandwidth for 4K at 120Hz or 8K at any refresh rate. Look for the official “Ultra High Speed” certification label on the package.
Copper Ultra High Speed cables reliably transmit full bandwidth up to about 3 meters (10 feet). Beyond that, active cables or fiber-optic solutions may be needed. Prices for a 3-meter certified cable range from $15 to $40 depending on the brand. The connector itself is identical to previous HDMI types (Type A and Type C), so backward compatibility with older ports is complete.
Common HDMI 2.1 Mistakes and Caveats
Not every port labeled “HDMI 2.1” delivers the full 48 Gbps. Some TVs and monitors cap the bandwidth at 18 Gbps despite the label — a situation often called “HDMI 2.1 pseudo.” Always check the manufacturer’s spec sheet for the actual bandwidth per port before buying.
Another frequent error is confusing HDMI 2.1 with the newer HDMI 2.2 standard released in 2025, which doubles the ceiling again to 96 Gbps. HDMI 2.1 is a 48 Gbps standard, not 96 Gbps. Early adopters should also know that some 2019 TVs offered only partial HDMI 2.1 support limited to 4K at 60Hz, so verify the feature set on older models. The HDMI Forum’s official 2.1 announcement details the full specification.
How To Set Up HDMI 2.1 On Your Devices
Getting HDMI 2.1 working requires three components — source, cable, and display — all certified for the spec. Here’s the step order that works:
- Verify your source supports HDMI 2.1. On PS5, go to Settings > Screen and Video > Video Output and confirm 4K at 120Hz is listed. On Windows 10 (version 2004+) or Windows 11, check that VRR and HDR are enabled in display settings.
- Replace the cable. Use a certified Ultra High Speed HDMI cable with the 48G label. Old cables will limit you to HDMI 2.0 speeds regardless of the ports.
- Enable the features on your TV. On LG OLED, enable HDMI Ultra HD Deep Color in Picture > Advanced Settings. Samsung and Sony models have similar toggles labeled “HDMI 2.1” or “Enhanced Format.”
- Test the output. Confirm the display shows 4K at 120Hz or 8K at 60Hz in the source device’s display settings. A the screen reports the target resolution and refresh rate without a blank or flicker.
HDMI 2.1 vs HDMI 2.0: Real-World Differences
The table below shows how specific devices and setups benefit from HDMI 2.1 compared to what HDMI 2.0 can deliver.
| Device | HDMI 2.1 Features Unlocked | HDMI 2.0 Limits |
|---|---|---|
| PlayStation 5 | 4K@120Hz, VRR, ALLM | 4K@60Hz, no VRR |
| Xbox Series X | 4K@120Hz, VRR, ALLM | 4K@60Hz, no VRR |
| NVIDIA RTX 30-Series GPU | 4K@120Hz, 8K@60Hz, VRR | 4K@60Hz (via HDMI), no VRR |
| AMD RX 6000-Series GPU | 4K@120Hz, VRR | 4K@60Hz, no VRR |
| LG OLED CX / C1 TV | Full 48 Gbps, all features | 4K@60Hz, limited HDR |
| Samsung QN90A QLED TV | Full 48 Gbps, all features | 4K@60Hz, limited HDR |
| Sony X90J TV | 2 full 48 Gbps ports | 4K@60Hz on other ports |
Putting HDMI 2.1 To Work
The bottom line: HDMI 2.1 matters most if you own or plan to buy a PS5, Xbox Series X, a high-end PC GPU, or a premium TV from 2020 or later. For those setups, the standard delivers genuine, visible improvements — smoother motion at 120 Hz, tear-free gaming with VRR, and richer HDR that adapts scene by scene. For everyone else, HDMI 2.0 remains sufficient for 4K at 60 Hz and basic HDR. If you’re upgrading, start with the cable: a certified Ultra High Speed cable is the cheapest and most critical piece of the chain, and it guarantees every other component can do its job.
FAQs
Is HDMI 2.1 worth the upgrade?
For gamers with a PS5, Xbox Series X, or a recent graphics card that can push 4K beyond 60 frames per second, HDMI 2.1 is worth it. The higher refresh rate, VRR, and reduced input lag improve responsiveness noticeably. For streaming movies at 4K, HDMI 2.0 is sufficient.
Do I need a new cable for HDMI 2.1?
Yes — older High Speed HDMI cables lack the 48 Gbps bandwidth HDMI 2.1 requires. A certified Ultra High Speed HDMI cable, identifiable by its “48G” certification label, is necessary for 4K at 120Hz or 8K at 60Hz. Using an old cable will limit you to HDMI 2.0 speeds.
Does HDMI 2.1 work with older devices?
HDMI 2.1 is fully backward compatible with HDMI 2.0, 1.4, and earlier standards. An Ultra High Speed cable will work with older ports, but it will operate at the older port’s maximum bandwidth. The connector shape is identical, so no adapter is needed.
What’s the difference between HDMI 2.1 and HDMI 2.2?
HDMI 2.2, released in 2025, doubles the bandwidth to 96 Gbps compared to HDMI 2.1’s 48 Gbps. HDMI 2.2 also adds new fixed-rate link protocols for higher uncompressed resolutions. HDMI 2.1 is the current mainstream standard; HDMI 2.2 is found on very recent high-end devices.
How do I know if my TV has HDMI 2.1?
Check the TV’s specifications for “48 Gbps” or “Ultra High Speed” listed on the HDMI ports. The manual or product page will indicate which ports support the full HDMI 2.1 feature set. Some TVs label only certain ports as “HDMI 2.1” while others remain at HDMI 2.0 speeds.
References & Sources
- HDMI Forum. “HDMI 2.1 Specification Announcement.” Official press release detailing the 48 Gbps spec, features, and release date.
- Wikipedia. “HDMI.” Technical reference for bandwidth, resolution tables, and version history.
- RTINGS.com. “HDMI 2.1 Overview.” Practical guide covering device compatibility, cable requirements, and common caveats.