Thunderbolt vs USB: Key Differences Explained

This article dives into the differences between Thunderbolt and USB, two popular interface types. We’ll compare Thunderbolt 3 and USB-C, highlighting their capabilities and compatibilities.

Thunderbolt Interface

Thunderbolt is a high-speed, dual-protocol I/O technology that offers excellent performance compared to older I/O technologies. It provides bi-directional speeds up to 10 Gbps. Think of it as a successor to Firewire, offering significant improvements.

Thunderbolt supports both data and video through a single cable, utilizing two protocols: PCI Express and DisplayPort. This 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. It’s also compatible with existing DisplayPort devices and uses native PCIe and DisplayPort software drivers. Thunderbolt even supports power delivery over the cable for bus-powered devices.

There are several versions of Thunderbolt:

• Thunderbolt 1: Supports 10 Gbps bi-directional, dual-channel data transfer.
• Thunderbolt 2: Supports 20 Gbps.
• Thunderbolt 3: Supports 40 Gbps.

USB Interface

USB (Universal Serial Bus) comes in various types based on the shape and design of the cable and port, including Type-A, Type-B, and Type-C. There are also different USB versions with varying capabilities in terms of speed and power, such as USB 1.1, USB 2.0, USB 3.0, USB 3.1 Gen. 1, and USB 3.1 Gen. 2.

The image above shows the connector types for USB 2.0 and USB 3.0.

Here are the pin designations for the USB Type-C plug connector:

The USB Type-C design, introduced in USB revision 3.1, offers several advantages:

• Data Speed: Supports up to 10 Gbps.
• Power Output: Supports a maximum of 20V/5A.
• Power Direction: Bi-directional, allowing devices to both send and receive power.
• Applications: Used in tablets, smartphones, laptops, and more.
• USB 2.0 Compatibility: Supports USB 2.0 LS/FS/HS capabilities.
• EMI/RFI Mitigation: Incorporates functionalities to reduce electromagnetic interference.

Key Differences Between Thunderbolt and USB

The following table summarizes the similarities and differences between Thunderbolt and USB:

It’s important to note that while Thunderbolt 3 uses the USB-C connector, not all host connections, cables, or devices with a USB-C connector support Thunderbolt 3.