HDMI深度解析：版本、特性和线缆规格

## HDMI Version History

| Version | Year | Max Resolution | Key Feature |
|---|---|---|---|
| HDMI 1.4 | 2009 | 4K@30Hz | ARC, Ethernet |
| HDMI 2.0 | 2013 | 4K@60Hz | HDR10 |
| HDMI 2.0b | 2016 | 4K@60Hz | HDR10+, HLG |
| HDMI 2.1 | 2017 | 10K@120Hz | eARC, VRR, ALLM, QFT |

## Cable Ratings Explained

HDMI cables come in four official speed ratings:

1. **Standard Speed** (Category 1): Up to 1080i. Obsolete.
2. **High Speed** (Category 2): 4K@30Hz, 1080p@60Hz. Most common.
3. **Premium High Speed**: Certified for 4K@60Hz with HDR.
4. **Ultra High Speed** (Category 3): Required for HDMI 2.1 features (4K@120Hz, 8K).

## Do You Need a New Cable?

- **4K@60Hz TV + streaming**: High Speed cable is fine
- **4K@120Hz gaming (PS5, Xbox)**: Ultra High Speed required
- **eARC soundbar**: Ultra High Speed recommended
- **8K TV**: Ultra High Speed mandatory

## Common Pitfalls

- HDMI cables don't have 'versions' — they have speed ratings
- A 'HDMI 2.1 cable' is marketing speak for Ultra High Speed
- Cable length affects reliability: keep passive cables under 5m for 4K@120Hz