Understanding pixel clock is essential for anyone looking to push their monitor to higher refresh rates or verify cable compatibility.
What is Pixel Clock?
Pixel Clock (also called dot clock) is the frequency at which pixels are transmitted to the display, measured in MHz.
The Formula
Pixel Clock = (H Total × V Total × Refresh Rate) ÷ 1,000,000
Cable Bandwidth Limits
- HDMI 1.4: 340 MHz max
- HDMI 2.0: 600 MHz max
- DisplayPort 1.4: 810 MHz max
- HDMI 2.1: 1200 MHz max
Common Scenarios
- 1080p@240Hz needs ~580 MHz
- 1440p@165Hz needs ~650 MHz
- 4K@120Hz needs ~1190 MHz