- Connecting
- Need
- Answer
HDMI cable for 4K 120 Hz gaming
Get this
Ultra High Speed HDMI (48 Gbps certified), the cable for HDMI 2.1
Look for
- Ultra High Speed certification label
- Plug it into the TV's HDMI 2.1 / 4K 120 input
- 3 m or shorter for passive cables
Avoid
- Older cables: 4K 120 may drop out or fall back to 60 Hz
The numbers: 4K 120 Hz 10-bit
| Link | Needs | Has | Result |
|---|---|---|---|
| HDMI 2.0TV timing | 35.64 Gbps | 14.40 Gbps | Too much |
| HDMI 2.1 40G | 32.27 Gbps | 35.56 Gbps | Fits |
| HDMI 2.1 48G | 32.27 Gbps | 42.67 Gbps | Fits |
How the numbers are worked out
Reduced-blanking timing (VESA CVT-R2)
3840×2160 active → 3920 × 2287 total pixels per frame
3920 × 2287 × 120 Hz = 1075.80 MHz pixel clock
1075.80 MHz × 30.0 bits per pixel = 32.27 Gbps
10-bit colour, full RGB/4:4:4: 3 × 10 = 30.0 bits per pixel.
"Has" is the link's usable rate after line coding. DSC is modelled as up to 3:1 compression. Full method.