Bulk Transfers. Bulk Transfers are used for data which are not of the type Control, Interrupt, or Isochronous. Reliable exchange of data is ensured at the hardware level using error detection. Data are transferred in the same manner as in Interrupt Transfers, but have no defined polling rate.
USB 1.1 is also known as the full speed version of the first generation USB drives, with a throughput of 12 Mbps. USB 2.0 is a High-speed version that supports 480 Mbps. USB 3.1 Gen1 is a SuperSpeed version that support 5 Gbps.
Full Speed Frame Size: 1 ms Supported Transfer TypesMaximum Size of TransferMaximum Theoretical Throughput Control 64 bytes 64 kbytes/s Interrupt 64 bytes 64 kbytes/s Bulk 64 bytes 1.2 Mbytes/s Isochronous 1023 bytes 1023 kbytes/s
USB Standards StandardAlso Known AsMax. Data Transfer Speed USB 1.1 Full Speed USB 12 Mbps USB 2.0 Hi-Speed USB 480 Mbps USB 3.2 Gen 1 USB 3.0 USB 3.1 Gen 1 SuperSpeed 5 Gbps USB 3.2 Gen 2 USB 3.1 USB 3.1 Gen 2 SuperSpeed+ SuperSpeed 10Gbps 10 Gbps3 more rows
For USB 2.0 drives, the average read speed should be from 10 to 25 Mbps. The average range for write speeds is between 3 and 10 Mbps. To reach the high end of these ranges, using USB-C drives is highly recommended.
Maximum packet size of a bulk endpoint depends on the bus speed of the device. For full speed, high speed, and SuperSpeed; the maximum packet sizes are 64, 512, and 1024 bytes respectively.
Maximum packet size of a bulk endpoint depends on the bus speed of the device. For full speed, high speed, and SuperSpeed; the maximum packet sizes are 64, 512, and 1024 bytes respectively.
An endpoint can be configured to support four transfer types defined in the USB specification (Control Transfers, Interrupt Transfers, Isochronous Transfers, and Bulk Transfers).
The maximum packet size of the default endpoint depends on the speed of the device. The default endpoint of a high-speed device is 64 bytes; low-speed device is 8 bytes. The host acknowledges the data transaction by sending an ACK packet (#452) to the device. Let's calculate the amount of data returned.