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Connectors are identical for USB 2.0 and USB 1.x. Hi-Speed) - 480 Mbit/s (~57 MB/s) - all devices are backward compatible with USB 1.1.
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USB 1.1 - 12 Mbit/s (~1.43 MB/s) - all USB 1.1 hubs support full- bandwidth. Typical SuperSpeed USB 3.0 external hard drives can transfer large files at ~70 MB/s The USB standard supports the following speeds: USB 1.0 - 1.5 Mbit/s (~183kB/s) - intended primarily to save cost in low- bandwidth human interface devices (HID) such as keyboards, mice, and joysticks. According to a USB-IF chairman, "at least 10 to 15 percent of the stated peak 60 MB/s (480 Mbit/s) of Hi-Speed USB goes to overhead - the communication protocol between the card and the peripheral. This represents ~70% of the total available bandwidth.
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Typical hi-speed USB 2.0 hard drives can be written to at rates around 25-30 MB/s, and read at 30-40 MB/s.
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