Interactive Display Bandwidth Calculator
Estimate required video payload and link rate for HDMI, DisplayPort, embedded links, and custom pipelines.
| Interface | Effective Payload (Gbps) | Headroom | Result |
|---|---|---|---|
| Calculation results will appear here. | |||
What this display bandwidth calculator tells you
Display links are easy to underestimate. A resolution and refresh rate look simple on paper, but the physical link has to carry color data, timing overhead, and sometimes encoding overhead too. This calculator helps you estimate:
- Raw active video data rate from resolution, refresh, and color format.
- Payload bandwidth after timing/blanking overhead and optional compression.
- Encoded link rate once protocol overhead (8b/10b, 16b/18b, 128b/132b) is included.
- Per-lane speed for multi-lane interfaces.
Core formula used
1) Pixels per second
pixel_rate = width × height × refresh
2) Bits per pixel
bpp = bits_per_channel × 3 × chroma_factor
Chroma factor is 1.0 for 4:4:4, 0.6667 for 4:2:2, and 0.5 for 4:2:0.
3) Active video data rate
active_gbps = pixel_rate × bpp / 1e9
4) Timing overhead and compression
payload_gbps = active_gbps × (1 + blanking_percent/100) / compression_ratio
5) Link encoding overhead
line_rate_gbps = payload_gbps × encoding_factor
Why blanking overhead matters
The display stream usually includes non-active intervals (front porch, sync, back porch). Depending on timing standard and link mode, overhead may be small (reduced blanking) or much larger (legacy timing). If your real-world setup fails despite matching “headline” bandwidth, try increasing blanking overhead in the calculator to model more conservative timings.
Understanding chroma subsampling and color depth
Chroma subsampling reduces color detail bandwidth while keeping luma detail high. For desktop text and UI, 4:4:4 is typically preferred. For video playback, 4:2:2 and 4:2:0 can be acceptable and significantly reduce required bandwidth.
- 4:4:4: Best for desktop clarity and fine text.
- 4:2:2: Common compromise in some high refresh modes.
- 4:2:0: Major bandwidth reduction, often used for TV/video workflows.
Going from 8 bpc to 10 bpc increases color precision and HDR quality, but it also increases data rate by 25%.
Compression (DSC) in practical terms
Display Stream Compression (DSC) can unlock high-resolution, high-refresh, high-bit-depth modes that would otherwise exceed a link’s payload. In the calculator, choose a compression ratio greater than 1.0 to model this. Keep in mind both source and sink must support the same compression method.
Quick planning workflow
- Enter your target resolution and refresh rate.
- Set color depth and chroma format you want to run daily.
- Add realistic blanking overhead (start around 3–8%).
- Choose encoding overhead matching your interface generation.
- Check whether payload fits with enough headroom.
Common pitfalls when comparing specs
- Raw vs effective bandwidth: Marketing numbers are often raw line rates, not usable payload.
- Cable quality: Marginal cables can fail at top-end modes even if math says it should work.
- GPU/monitor firmware limits: Some combinations disable modes despite enough bandwidth.
- Port capabilities vary: Different ports on the same device may support different maximums.
Final note
This calculator is designed for fast estimation and planning. Real implementations include additional protocol details, safety margins, and device-specific constraints. Still, if your calculated payload is clearly above interface capability, you can confidently expect issues unless you lower refresh, reduce chroma/color depth, or enable compression.