- Connecting
- Need
- Answer
Cable for a 4K 60 Hz monitor
Get this
DisplayPort cable, USB-C to DisplayPort cable, full-featured USB-C cable, or Premium High Speed HDMI
Look for
- DisplayPort: any standard cable up to 2 m
- HDMI: "Premium High Speed" or "Ultra High Speed" label
- USB-C: marked 10Gbps or faster, or Thunderbolt
- USB-C to HDMI adapter: must say 4K 60Hz / HDMI 2.0
Avoid
- HDMI 1.4 adapters and hubs (4K 30 Hz)
- USB 2.0 USB-C charging cables (no video)
The numbers: 4K 60 Hz 8-bit
| 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 |
| DP 1.2 | 12.54 Gbps | 17.28 Gbps | Fits |
| USB-C DP 1.2 ×2 | 12.54 Gbps | 8.64 Gbps | Too much |
| USB-C DP 1.4 ×2 | 12.54 Gbps | 12.96 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.
"Has" is the link's usable rate after line coding. DSC is modelled as up to 3:1 compression. Full method.
Standards behind this answer
2010
DisplayPort 1.2
4K at 60 Hz since 2010, plus daisy-chaining (MST).
- data: 21.6 Gbps
- video: 4K 60 Hz / 1440p 144 Hz
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
DisplayPort over USB-C (Alt Mode)
How most USB-C ports send video. The USB-C pairs are handed over to DisplayPort.
- data: USB 2.0 or USB 3 alongside
- video: DP 1.4 (or 2.1) over USB-C
- power: USB PD at the same time