Understanding the Differences Between Thunderbolt and USB Protocols and Physical Interfaces

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Cables can be divided into transmission protocols and physical interfaces. Transmission protocols refer to communication languages, while physical interfaces refer to the compatibility methods of physical items.

The same physical interface can support different transmission protocols simultaneously to achieve backward compatibility.

Because physical interfaces all have fool-proof designs to prevent incorrect connections between different interfaces, this means that as long as your cable can be plugged in, it is normally compatible, only differing in which transmission protocol language is used to communicate and transfer data, with different languages having different bandwidth speeds.

Physical Interfaces

Interface Type	Usage	Interface
USB Type-A	Computer
USB Type-B	Scanner, Printer, etc.
USB Type-C	New computers, mobile phones, tablets, etc.
USB Mini-A	Old portable devices, deprecated
USB Mini-B	Old portable devices, deprecated
USB Mini-AB	Only as universal connector, deprecated
USB Micro-A	Deprecated
USB Micro-B	Mobile phones, tablets, etc.
USB Micro-AB	Only as universal connector, deprecated

USB Type-A Physical Interface

Usage: Computer

Male

USB Type-A

Female

USB Type-A

USB Type-B Physical Interface

Usage: Scanner, Printer

Male

USB Type-B

Female

USB Type-B

USB Type-C Physical Interface

Usage: New computers, mobile phones, tablets

Male

USB Type-C

Female

USB Type-C

USB Mini-A Physical Interface

Usage: Old portable devices, deprecated

Male

USB Mini-A

Female

USB Mini-A

USB Mini-B Physical Interface

Usage: Old portable devices, deprecated

Male

USB Mini-B

Female

USB Mini-B

USB Mini-AB Physical Interface

Usage: Only as universal connector, deprecated

Male

No Mini-AB Male

Female

USB Mini-AB

USB Micro-A Physical Interface

Usage: Deprecated

Male

USB Micro-A

Female

No Micro-A Female

USB Micro-B Physical Interface

Usage: Mobile phones, tablets

Male

USB Micro-B

Female

USB Micro-B

USB Micro-AB Physical Interface

Usage: Only as universal connector, deprecated

Male

No Micro-AB Male

Female

USB Mini-AB

Transmission Protocols

Thunderbolt Transmission Protocol

Developed by Intel
Protocol for data transmission

Version	Time	Manufacturer	Bandwidth	Physical Interface
Thunderbolt Development Version	2009	Intel	-
Thunderbolt	2011/2	Intel, Apple	10 Gbit/s	DisplayPort, PCI Express
Thunderbolt 2	2013	Intel, Apple	20 Gbit/s	DisplayPort, PCI Express
Thunderbolt 3	2015/6	Intel	40 Gbit/s	USB Type-C
Thunderbolt 4	2020/7	Intel	40 Gbit/s	USB Type-C

Thunderbolt Versions

Thunderbolt

Transfer rate 10 Gbit/s
Up to six peripheral devices
Can supply 10W power to peripherals
Cable length up to 10 meters

Physical Interface

PCI Express 2.0 x4
DisplayPort 1.1a

Thunderbolt - Display Port

Thunderbolt 2

Transfer rate 20 Gbit/s
First and second version Thunderbolt bandwidth are both 20 Gbit/s, so cables are compatible

Physical Interface

PCI Express 2.0 x4
DisplayPort 1.2

Thunderbolt 2 - Display Port

Thunderbolt 3

Transfer rate 40 Gbit/s
Physical interface USB Type-C
Maximum power delivery 100W
Can connect 2 4K resolution displays, or 1 5K resolution display
Supports HDMI 2.0 (4K 60Hz) and DisplayPort 1.2 (5K 60Hz)

Physical Interface

PCI Express 3.0 x4
USB 3.1 Gen2
DisplayPort 1.2

Thunderbolt 3 - USB Type-C

Thunderbolt 4

Transfer rate 40 Gbit/s
Physical interface USB Type-C
USB 4 protocol support and data transfer speed
Supports 2 4K displays (DisplayPort 1.4)

Physical Interface

USB Type-C
DisplayPort 1.4

Thunderbolt 4 - USB Type-C

USB Transmission Protocol

Version	Transfer Speed (bit)	Physical Interface
USB 1.0	1.5 Mbps	Type-A, Type-B, Mini-A, Mini-B, Mini-AB (female only), Micro-A, Micro-B, Micro-AB (female only)
USB 1.1	12 Mbps	Type-A, Type-B, Mini-A, Mini-B, Mini-AB (female only), Micro-A, Micro-B, Micro-AB (female only)
USB 2.0	480 Mbps	Type-A, Type-B, Mini-A, Mini-B, Mini-AB (female only), Micro-A, Micro-B, Micro-AB (female only)
USB 3.1 GEN 1	5 Gbps	Type-A, Type-B, Type-C (female only), Micro-B Super speed
USB 3.1 GEN 2	10 Gbps	Type-A, Type-B, Type-C (female only), Micro-B Super speed
USB 3.2 Gen 2x2	20 Gbps	Type-A, Type-B, Type-C (female only), Micro-B Super speed
USB 4	40 Gbps	Type-C