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MJhab1205 Author

Level 1

5 points

slow usb transfer

Transferring video files sized 1-2 gb to USB-C 3.0 drives. Takes 30-40 min for each file. This just started happening in the last week. I don't know what or why this is happening. Help !!

MacBook Air 13″, macOS 11.6

Posted on Jul 27, 2023 7:07 AM

Top-ranking reply

Grant Bennet-Alder

Level 10

148,617 points

Posted on Jul 28, 2023 7:19 AM

USB-3 is capable for 5,000 M bits/sec, or about 500 M Bytes/sec.

But using USB-3 depends on making certain that every cable and adapter has all nine conductors, and is of high quality. Often, USB-3 adapters and cable have a Blue insert to indicate that carry nine conductors instead of USB-2 four conductors.

Any other USB-2 device on the same USB Bus can cause all the devices on that bus to downshift to USB-2 speeds, 480 M bits/sec or 48 M Bytes/sec, about the speed of a rotating magnetic drive.

USB thumb drives can be very slow. Even thumb drives that can transfer data at USB-3 speeds, may not be able to store or read data at those speeds for more than a moment.

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