Display Bandwidth Checker
Check whether your resolution, refresh rate and color format will actually run over HDMI, DisplayPort or USB-C Alt-Mode — with the exact Gbps required vs. the link maximum and the fix when it does not fit.
No sign-up, no account, computed in your browser.
Result
- Required
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- Raw (no DSC)
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- Link maximum
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- Headroom
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- Bits per pixel
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Quick picks — most-asked combinations
Display configuration
Cable guidance
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To make it work
- Swap to a port that fits — see the smallest-upgrade suggestion above.
- Enable DSC in your GPU control panel (NVIDIA: Display → Set Custom Resolution → Compression; AMD: Display → DSC), where supported.
- Use a cable certified for the interface's full bandwidth (see the cable guidance above).
- Lower the color format (RGB 4:4:4 → YCbCr 4:2:2 or 4:2:0) or the bit depth, then re-check.
How to use the Display Bandwidth Checker
How to use
- Pick the interface (HDMI, DisplayPort or USB-C Alt-Mode). For USB-C, also select the tunneled DP version.
- Pick a resolution preset or enter a custom width/height, and a refresh rate.
- Choose the bit depth and color format.
- The verdict and required Gbps update instantly as you change anything — nothing is sent anywhere.
What the numbers mean
- Required Gbps: the real signal bandwidth after adding 10% for blanking and accounting for 90% link encoding efficiency.
- Link maximum: the total bandwidth of the chosen standard, per the VESA/HDMI specification.
- Headroom: the percentage of capacity left over. Under 5% means a tight fit; negative means the configuration does not fit.
- DSC 3:1: reversible signal compression that divides the required bandwidth by 3. Only DisplayPort 1.4 and newer support it.
- Color formats: RGB 4:4:4 uses 3 × the bit depth per pixel; YCbCr 4:2:2 uses 2 ×; YCbCr 4:2:0 uses 1.5 ×.
Use cases
Five real situations where the bandwidth math decides what works.
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Wiring up a new monitor
Pick the resolution and refresh you want, check the interface, and buy the right cable before you plug anything in.
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Why the advertised Hz is missing
A 144 Hz monitor stuck at 60 Hz? The 4K144 · DP 1.4 quick pick shows exactly why: 35.04 Gbps needed against a 32.4 Gbps link — the fix is DSC or a better port.
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Choosing between HDMI and DisplayPort
Same monitor, two cables. Compare the headroom over HDMI 2.1 and DP 2.1 and use the port with the bigger safety margin.
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Buying a cable that matches the port
A DP 2.1 port is wasted on a 10.8 Gbps cable. The cable guidance tells you passive vs. active before you buy.
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Planning a high-refresh ultrawide setup
1440p240, 5K120 or 8K gaming — check the bandwidth math before the monitor arrives and find out which interface (or DSC) you need.
Frequently asked questions
- Will 4K 144 Hz work over HDMI 2.0?
- No. 4K 144 Hz in 8-bit RGB needs 35.04 Gbps; HDMI 2.0 caps at 18 Gbps and does not support DSC. HDMI 2.1 (48 Gbps) carries it with 27% headroom, and DP 1.4 works once DSC 3:1 is enabled.
- What does DSC do to image quality?
- DSC 3:1 is reversible compression — the GPU encodes it and the display decodes it, so it is lossless when supported end to end. Every DisplayPort 1.4 and newer card and panel ships with it; HDMI does not support it at all.
- Why does the checker add 10% extra bandwidth?
- The pixel clock carries extra bits for blanking (the gaps between frames), so the real link load is about 10% above the raw pixel rate. The 90% encoding efficiency term covers link overhead; together they match the usable maximums VESA and HDMI publish.
- Is YCbCr 4:2:0 worth it for gaming?
- Usually not — it discards color detail, so sharp text and fast motion look softer. Use it only when the link cannot fit your settings at 4:4:4 or 4:2:2 and the quality drop is acceptable to you.
- Does USB-C Alt-Mode support DSC?
- Yes — USB-C Alt-Mode carries DisplayPort signals, so it supports DSC exactly like the tunneled DP version you pick in this checker. USB-C 4 / Thunderbolt naming is unrelated: the bandwidth is whatever the tunneled DP version allows.