HDMI Bandwidth
Bandwidth is the ceiling on what a cable can carry at one time. These listings state it in gigabits per second, and that one figure decides which combinations of resolution and refresh rate survive the trip.
Two figures stated
The cables listed here state either 18 Gbps or 48 Gbps, and each listing pairs its figure with the resolution and refresh combinations it claims. Those pairs are transcribed exactly as the listings give them, because the pairing is the claim, not the raw number.
A higher figure does not improve a picture that already fits under a lower one. It raises the ceiling. If nothing in the room is pushing against the old ceiling, raising it changes nothing you can see.
The weakest link
A signal passes through a source, a cable, sometimes a receiver or a switch, and then a display. The lowest capability anywhere in that chain sets what arrives, and a cable cannot lift anything above it.
That is why a cable is rarely the first thing to change. Work out what each end of the chain is capable of before deciding that the wire between them is what is short.
Certified and stated
Some listings here describe a cable as certified to a standard. Others simply state a figure. Those are different kinds of claim: one points at a testing program, the other is a number on a page.
This site repeats each listing in its own words rather than flattening them into one column. Where a listing says certified, the card says certified. Where it does not, the card does not.
Length and bandwidth
Over a short run between a console and a panel on the same shelf, bandwidth claims rarely decide anything. Over a long run behind a wall, the same claim is the thing you are relying on and cannot easily test.
Work out the length first. The figure to care about follows from the distance, not the other way round.
Stated and not stated
The left column is copied from the listings word for word, including the pairing of a speed figure with the resolutions it claims. Splitting that pair apart is how a cable ends up chosen on one number.
Stated
- Bandwidth in Gbps
- Resolution and refresh rate combinations
- HDCP version
- eARC support, where a listing names it
- Whether the listing calls the cable certified
Not stated
- What your source and display actually negotiate between them
- Conductor gauge
- Signal behavior over the stated length in your walls
- Whether a cable already installed in your wall meets the same figure
Common errors
| Error | Consequence | What to do |
|---|---|---|
| Buying a higher bandwidth figure to fix a picture problem | The cable changes and the limitation, which was at one end of the chain, does not. | Establish what the source and the display are each capable of first. |
| Reading a bandwidth figure as permission to go inside a wall | A cable with no jacket rating ends up in a cavity it was never made for. | Treat the speed figure and the in-wall marking as two separate checks. |
| Assuming an existing wall cable matches a new one | A new display is limited by a run nobody has looked at since it was installed. | Find out what is actually in the wall before buying anything to feed it. |
Before starting
Note
Every bandwidth figure quoted on this site is what a listing states. Nothing here has been measured, and no cable is described as performing better than its listing claims.