Introduccion A Thunderbolt

Technology Brief
Interconnect Technology

Thunderbolt™ Technology
The Transformational PC I/O

Thunderbolt™ technology is a transformational I/O innovation that provides a leap in performance over current I/O technologies with 10 Gbps of full-duplex bandwidth per channel. It significantly simplifies the end-user experience by concurrently supporting data (PCI Express*) and display(DisplayPort) connections over a single cable. Thunderbolt products may be connected using electrical or optical cables. Thunderbolt technology enables flexible and innovative system designs by allowing multiple, high-performance, PCI Express and DisplayPort devices to attach to a computer through a single physical connector.

Key Features
• Dual-channel 10Gbps per port • Bi-directional • Dual-protocol(PCI Express and DisplayPort) • Compatible with existing DisplayPort devices • Daisy-chained devices • Electrical or optical cables • Low latency with highly accurate time synchronization • Uses native protocol software drivers • Power over cable for bus-powered devices

Why Thunderbolt Technology Matters
Data transfers for backup, sharing, and editing are faster with Thunderbolt technology,significantly reducing times to complete these tasks. For time-sensitive data, such as video and audio during creation and playback, data transfers can be critical to the success of the work. Thunderbolt technology was specifically designed with video and audio applications in mind with inherently low latency and highly accurate time synchronization capabilities.

For some power users, optimalworkflows can be had with workstation performance and expandability while using a thin and light laptop. Thunderbolt technology enables using the thinnest and lightest laptops, connected, with “in the box” performance over a single external cable, to high-performance external media drives, HD displays, HD media capture and editing systems, as well as legacy I/O hubs and devices, for the utmost inperformance, simplicity and flexibility.

Rethinking I/O
As every generation of information technology progresses, I/O technologies evolve to provide higher bandwidth for getting data into and out of computers. At its simplest, two discrete types of I/O have resulted – display (with formatted video and audio components), and data. Traditional approaches to this evolution have been to make anexisting technology faster. Thunderbolt technology combines the next step in higher performance with the innovation of mapping two of the most fundamental I/O protocols at the heart of computing (PCI Express and DisplayPort), onto a single highly efficient metaprotocol, transmitting them over a single cable, and managing the

Figure 1. Thunderbolt™ cables expand a thin and light laptop to ahighresolution display and high-performance storage in a simple daisy chain.

traffic routing (supporting daisy chaining and hot-plugging devices) with intelligent hardware controllers. The choice of PCI Express was clear, providing for off-the-shelf controller use to attach to nearly any technology imaginable, and the choice of DisplayPort was equally clear for meeting the needs of the PC industry withcapabilities like support for greater-than-highdefinition display resolutions, and support for up to 8 channels of high-definition audio.

Application-specific Protocol Stacks
PCIe DisplayPort

Common Transport Layer Electrical/Optical Layer Connector and Cable

Protocol Architecture
Thunderbolt technology is based on a switched fabric architecture with full-duplex links. Unlike bus-basedI/O architectures, each Thunderbolt port on a computer is capable of providing the full bandwidth of the link in both directions with no sharing of bandwidth between ports or between upstream and downstream directions. The Thunderbolt protocol architecture can be abstracted into four layers as shown in Figure 2. A Thunderbolt connector is capable of providing two full-duplex channels. Each...