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A comment on M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2. Parent comment

Re:M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2 by mlindner on Monday April 18, 2022 @05:57AM (#31068950)
If the cable is wrecking signal integrity, the port could absolutely change things if the ports have slightly different hardware that's generating the signal. RF does weird things.

Just as a very simplistic analog DC example, if you have wires that are both sitting at 3V but one can only drive 100 mA while the other can drive 1A. If you only draw 50 mA they'd look near identical but as soon as soon as you tried to get close to 100 mA they'd both diverge heavily. You could advertise both at 50 mA for sales purpose but if they were hooked up with a bad high resistance cable they'd look very different.

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Re:M1 Thunderbolt ports don’t fully support USB 3.1 Gen 2 by nottorp on Monday April 18, 2022 @08:17AM (#31069691)
As a less technical anecdote, I bought one of those usb "sound cards" and it had noise when plugged into the front usb ports but worked fine into the back ones on the same PC.

The sound was transmitted digitally and didn't need that much bandwidth, so the only explanation is "dirty" power on the power wires, I think?

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