I get the difference between something like USB 2 and USB 3 where USB 3 has more wires but how does one USB C cable manage to transfer data faster than another USB C cable that has the exact same number of paths?
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With a faster switching signal. The problem is that the faster you go, the more of a problem defects in the cable are, a pair of data lines with mismatched length, connections that cause internal reflections(because the connector has a different impedance than the cable), and crosstalk between different sets of data lines all become problems.
This is also why the cables rated for the fastest data transfer speeds also are generally pretty short. Signal integrity is harder with longer cables.
With a faster switching signal. The problem is that the faster you go, the more of a problem defects in the cable are, a pair of data lines with mismatched length, connections that cause internal reflections(because the connector has a different impedance than the cable), and crosstalk between different sets of data lines all become problems.
This is also why the cables rated for the fastest data transfer speeds also are generally pretty short. Signal integrity is harder with longer cables.
Imagine if each part of a signal on a cable was someone talking. Higher bandwidth means more people talking. If you put everyone talking in a hallway it gets really noisy and you can’t hear anyone. A low quality cable is like a small hallway, very quickly you can’t make out the conversations because it’s too noisy.
A really high quality cable design allows everyone to talk (the multiple signals) without being too noisy to hear. A good one let’s people whisper and still be heard making it possible for even more people to talk.
Imagine if each part of a signal on a cable was someone talking. Higher bandwidth means more people talking. If you put everyone talking in a hallway it gets really noisy and you can’t hear anyone. A low quality cable is like a small hallway, very quickly you can’t make out the conversations because it’s too noisy.
A really high quality cable design allows everyone to talk (the multiple signals) without being too noisy to hear. A good one let’s people whisper and still be heard making it possible for even more people to talk.
Imagine if each part of a signal on a cable was someone talking. Higher bandwidth means more people talking. If you put everyone talking in a hallway it gets really noisy and you can’t hear anyone. A low quality cable is like a small hallway, very quickly you can’t make out the conversations because it’s too noisy.
A really high quality cable design allows everyone to talk (the multiple signals) without being too noisy to hear. A good one let’s people whisper and still be heard making it possible for even more people to talk.
> how does one USB C cable manage to transfer data faster than another USB C cable that has the exact same number of paths?
It rarely actually does.
As others have mentioned, the more likely cause of this is that they actually have different wires.
USB C cables that look identical (and have the same connectors) very commonly have a different number of wires inside.
But it *is* possible for two USB C cables with the same number of wires to be certified for different speeds.
Mostly this comes down to cable length and shielding.
In the early days of USB C (back when speeds were slower, in the USB 3.0 days), cables were allowed to be up to 2m long and were allowed to have relatively poor shielding.
“Shielding” here is kind of like a sleeve that protects the wires from outside radio interference (like your microwave oven).
If cables are not well shielded and/or are long, they can pick interference more readily.
And the faster the speed on the wire pairs, the more likely some interference will cause the signal to fail to be read correctly.
When we moved from USB 3.0 to USB 3.1, speeds increased, which means standards for cables got more strict.
Cables could be no longer than 1m long.
If you want the fastest speeds with USB 4.0, we’re still using the same USB C cables, but again the standards have tightened up.
Cables can be no longer than 80cm.
> how does one USB C cable manage to transfer data faster than another USB C cable that has the exact same number of paths?
It rarely actually does.
As others have mentioned, the more likely cause of this is that they actually have different wires.
USB C cables that look identical (and have the same connectors) very commonly have a different number of wires inside.
But it *is* possible for two USB C cables with the same number of wires to be certified for different speeds.
Mostly this comes down to cable length and shielding.
In the early days of USB C (back when speeds were slower, in the USB 3.0 days), cables were allowed to be up to 2m long and were allowed to have relatively poor shielding.
“Shielding” here is kind of like a sleeve that protects the wires from outside radio interference (like your microwave oven).
If cables are not well shielded and/or are long, they can pick interference more readily.
And the faster the speed on the wire pairs, the more likely some interference will cause the signal to fail to be read correctly.
When we moved from USB 3.0 to USB 3.1, speeds increased, which means standards for cables got more strict.
Cables could be no longer than 1m long.
If you want the fastest speeds with USB 4.0, we’re still using the same USB C cables, but again the standards have tightened up.
Cables can be no longer than 80cm.
> how does one USB C cable manage to transfer data faster than another USB C cable that has the exact same number of paths?
It rarely actually does.
As others have mentioned, the more likely cause of this is that they actually have different wires.
USB C cables that look identical (and have the same connectors) very commonly have a different number of wires inside.
But it *is* possible for two USB C cables with the same number of wires to be certified for different speeds.
Mostly this comes down to cable length and shielding.
In the early days of USB C (back when speeds were slower, in the USB 3.0 days), cables were allowed to be up to 2m long and were allowed to have relatively poor shielding.
“Shielding” here is kind of like a sleeve that protects the wires from outside radio interference (like your microwave oven).
If cables are not well shielded and/or are long, they can pick interference more readily.
And the faster the speed on the wire pairs, the more likely some interference will cause the signal to fail to be read correctly.
When we moved from USB 3.0 to USB 3.1, speeds increased, which means standards for cables got more strict.
Cables could be no longer than 1m long.
If you want the fastest speeds with USB 4.0, we’re still using the same USB C cables, but again the standards have tightened up.
Cables can be no longer than 80cm.
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