Thunderbolt 2 vs Thunderbolt 3: Key Differences Explained

This article explores the differences between Thunderbolt 2 and Thunderbolt 3, building upon a general understanding of Thunderbolt technology.

What is Thunderbolt?

Thunderbolt is a high-speed, dual-core I/O protocol designed to deliver exceptional performance, exceeding that of many contemporary I/O technologies. It boasts a bidirectional speed of 10 Gbps.

Thunderbolt serves as a successor to the Firewire interface. It supports both data and video transmission over a single cable, utilizing a dual protocol system involving PCI Express and DisplayPort. Notably, it allows for daisy-chaining up to 6 devices. This technology makes it possible to connect laptops to high-performance storage, displays, and multimedia devices using just one cable. Thunderbolt is also compatible with existing DisplayPort devices. It leverages native PCIe and DisplayPort Protocol software drivers and supports power delivery over the cable for bus-powered devices.

Different versions of Thunderbolt exist, including Thunderbolt 1, Thunderbolt 2, and Thunderbolt 3. While Thunderbolt 1 offers 10 Gbps bidirectional and dual-channel data transfer, Thunderbolt 2 and Thunderbolt 3 significantly increase these speeds to 20 Gbps and 40 Gbps, respectively.

Thunderbolt 2

Here are some key features of the Thunderbolt 2 interface:

• Introduction: Launched in 2013.
• Connector: Uses the Mini DisplayPort (MDP) connector.
• Bit Rate: Supports a bit rate of 20 Gbps.
• Protocols: Employs 4 x PCI Express 2.0 and DisplayPort 1.2 protocols.

Thunderbolt 3

Thunderbolt 3 embraced the USB-C format, allowing for the use of standard USB-C cables. It delivers Thunderbolt capabilities through USB-C at a speed of 40 Gbps. Compared to other cables, a single Thunderbolt 3 cable offers four times the data and twice the video bandwidth, along with increased power delivery. Thunderbolt 3 offers a superior USB-C experience with enhanced speed and higher pixel density support.

Key features include:

• Protocol: Bi-directional, dual protocol (PCI Express and DisplayPort)
• PCIe Lanes: 4 lanes of PCI Express Gen 3
• DisplayPort Lanes: 8 Lanes of DisplayPort 1.2
• Display Support: Supports two 4K displays
• Power Delivery: Up to 100W system charging and 15W to bus-powered devices (based on USB delivery specifications)

Thunderbolt 2 vs 3: A Detailed Comparison

The following table highlights the key differences between Thunderbolt 2 and Thunderbolt 3:

Thunderbolt 4 Interface