Do I need a new HDMI cable for 4K at 60 Hz?
AnswerMaybe
Possibly. 4K 60 Hz needs about 18 Gbps on the wire (HDMI 2.0). A cable sold as High Speed is only tested to 10.2 Gbps. Many older High Speed cables work at short lengths, but flickering, sparkles or a blank screen at 4K 60 mean you need a certified Premium High Speed or Ultra High Speed cable.
4K 60 Hz, 8-bit (TV timing)
| Link | Needs | Has | Result |
|---|---|---|---|
| HDMI 1.4TV timing | 14.26 Gbps | 8.16 Gbps | Too much |
| HDMI 2.0TV timing | 14.26 Gbps | 14.40 Gbps | Fits |
How the numbers are worked out
Reduced-blanking timing (VESA CVT-R2)
3840×2160 active → 3920 × 2222 total pixels per frame
3920 × 2222 × 60 Hz = 522.61 MHz pixel clock
522.61 MHz × 24.0 bits per pixel = 12.54 Gbps
8-bit colour, full RGB/4:4:4: 3 × 8 = 24.0 bits per pixel.
HDMI 1.4/2.0, standard TV timing (CTA-861)
3840×2160 active → 4400 × 2250 total pixels per frame
4400 × 2250 × 60 Hz = 594.00 MHz pixel clock
594.00 MHz × 24.0 bits per pixel = 14.26 Gbps
8-bit colour, full RGB/4:4:4: 3 × 8 = 24.0 bits per pixel.
"Has" is the link's usable rate after line coding. DSC is modelled as up to 3:1 compression. Full method.
4K 60 Hz HDR, 10-bit 4:2:2
4K 60 Hz HDR, 10-bit 4:4:4
| Link | Needs | Has | Result |
|---|---|---|---|
| HDMI 2.0TV timing | 17.82 Gbps | 14.40 Gbps | Too much |
| HDMI 2.1 40G | 15.68 Gbps | 35.56 Gbps | Fits |
HDMI cables are named by tested speed, not version: High Speed (10.2 Gbps), Premium High Speed (18 Gbps) and Ultra High Speed (48 Gbps). For 4K 60 Hz, Premium High Speed is the minimum certified grade. Ultra High Speed costs little more and covers 4K 120 too.
The standards involved
HDMI 2.0
The 4K 60 Hz standard. 18 Gbps, HDR from 2.0a, but not enough for 4K 120.
- data: 18 Gbps
- video: 4K 60 Hz
HDMI 1.4
1080p at any common refresh rate, 4K only at 24–30 Hz. Introduced ARC.
- data: 10.2 Gbps
- video: 4K 30 Hz / 1080p 120 Hz
HDMI 2.1
48 Gbps, 4K 120 Hz, 8K, VRR and eARC. The console and gaming-TV standard.
- data: 48 Gbps
- video: 4K 144 Hz / 8K 60 Hz (DSC)