The theoretical maximums are as follows:
In bits per second, that is:
- USB 1.1 = 12 Mbit/s
- Firefire 400 = 400 Mbit/s
- USB 2.0 = 480 Mbit/s
- FireWire 800 = 800 Mbit/s
- USB 3.0 = 5 Gbit/s
- USB 3.1 = 10 Gbit/s
- eSATA = Up to 6 Gbit/s (750 MB/s) right now as it depend on the internal SATA chip.
- Thunderbolt = 10 Gbit/s × 2 (2 channels)
- Thunderbolt 2 = 20 Gbit/s
- Thunderbolt 3 = 40 Gbit/s
In Bytes per second, that is:
- USB 1.1 = 1.5 MB/s
- Firefire 400 = 50 MB/s
- USB 2.0 = 60 MB/s
- FireWire 800 = 100 MB/s
- USB 3.0 = 625 MB/s
- USB 3.1 = 1.21 GB/s
- eSATA = 750 MB/s
- Thunderbolt = 1.25 GB/s × 2 (2 channels)
- Thunderbolt 2 = 2.5 GB/s
- Thunderbolt 3 = 5 GB/s
However, this does not provide the actual answer. As an example, FireWire 400 is a serial connection. The entire 400 Mbps is available for data transfer. USB 2.0 sends command and control data through the same connection the data uses limiting the 480 Mbps connection to 380 to 400 Mbps. When considering throughput the list looks entirely different.
For the speed/throughput/bandwidth of more devices have look at this article on wikipedia http://en.wikipedia.org/wiki/List_of_device_bit_rates#Peripheral
