[1] Thunderbolt combines PCI Express (PCIe) and DisplayPort (DP) into two serial signals,[9][10] and additionally provides DC power via a single cable.

[20] Jason Ziller, head of Intel's Optical I/O Program Office showed the internal components of the technology under a microscope and the sending of data through an oscilloscope.

[26] In 2009, Intel officials said the company was "working on bundling the optical fiber with copper wire so Light Peak can be used to power devices plugged into the PC.

"[28] Light Peak aimed to make great strides in consumer-ready optical technology, by then having achieved "[connectors rated] for 7,000 insertions, which matches or exceeds other PC connections ... cables [that were tied] in multiple knots to make sure it didn't break and the loss is acceptable," and, "You can almost get two people pulling on it at once and it won't break the fibre."

"[29] In January 2011, Intel's David Perlmutter told Computerworld that initial Thunderbolt implementations would be based on copper wires.

[12][32][33] The version from Corning contains four 80/125 μm VSDN (Very Short Distance Network) fibers to transport an infrared signal up to 190 m (600 ft).

CNET's Brooke Crothers said it was rumored that the early-2011 MacBook Pro update would include some sort of new data port, and he speculated it would be Light Peak (Thunderbolt).

[44] At the time, there were no details on the physical implementation, and mock-ups appeared showing a system similar to the earlier Intel demos using a combined USB/Light Peak port.

The Target Display mode on iMacs requires a Thunderbolt cable to accept a video-in signal from another Thunderbolt-capable computer.

[61] In July 2011, Sony released its Vaio Z21 line of notebook computers that had a "Power Media Dock" that uses optical Thunderbolt (Light Peak) to connect to an external graphics card using a combination port that behaves like USB electrically, but that also includes the optical interconnect required for Thunderbolt.

[82][83][84] Intel offers three varieties for each of the controllers:[85] This follows previous practice, where higher-end devices such as the second-generation Mac Pro, iMac, Retina MacBook Pro, and Mac Mini use two-port controllers; while lower-end, lower-power devices such as the MacBook Air use the one-port version.

[82][83][84] Devices with Thunderbolt 3 ports began shipping at the beginning of December 2015, including notebooks running Microsoft Windows (from Acer, Asus, Clevo, HP, Dell, Dell Alienware, Lenovo, MSI, Razer, and Sony), as well as motherboards (from Gigabyte Technology), and a 0.5 m Thunderbolt 3 passive USB-C cable (from Lintes Technology).

On 8 January 2018, Intel announced a product refresh (codenamed Titan Ridge) with "enhanced robustness" and support for DisplayPort 1.4.

On September 12, 2023, Intel previewed Thunderbolt 5 (codenamed Barlow Ridge), aligned to the USB Implementers Forum's (USB-IF) USB4 2.0 specification.

On 24 May 2017, Intel announced that Thunderbolt 3 would become a royalty-free standard to OEMs and chip manufacturers in 2018, as part of an effort to boost the adoption of the protocol.

[131] Before March 2019, there were no AMD chipsets or computers with Thunderbolt support released or announced due to the certification requirements (Intel did not certify non-Intel platforms).

The first Thunderbolt peripheral devices appeared in retail stores only in late 2011, following Apple's release of its first Thunderbolt-equipped computer in early 2011 with MacBook Pro, with the relatively expensive Pegasus R4 (4-drive) and Pegasus R6 (6-drive) RAID enclosures by Promise Technology aimed at the prosumer and professional market, initially offering up to 12 TB of storage, later increased to 18 TB.

Sales of these units were hurt by the 2011 floods in Thailand (who manufacture much of the world's supply of hard-drives) resulting in a cut to worldwide hard-drive production and a subsequent driving-up of storage costs, hence the retail price of these Promise units increased in response, contributing to a slower take-up of the devices.

It also took some time for other storage manufacturers to release products: most were smaller devices aimed at the professional market, and focused on speed rather than high capacity.

Many storage devices were under 1 TB in size, with some featuring SSDs for faster external-data access rather than standard hard-drives.

Other companies have offered interface products that can route multiple older, usually slower, connections through a single Thunderbolt port.

In contrast, the HP Thunderbolt G4 dock will activate the PCIe NIC on all Thunderbolt/USB4 capable PCs based on Intel or AMD CPUs.

Exceptions included Sonnet Technologies' highly priced professional units, and Drobo's 4- and 5-drive enclosures, the latter featuring their own BeyondRAID proprietary data-handling system.

In mid-2012, LaCie, Drobo, and other device makers started to swap out one of the two Thunderbolt ports for a USB 3.0 connection on some of their low-to-mid end products.

Apple released its first Thunderbolt-equipped computer in early 2011 with MacBook Pro, and have continued to immediately update their devices with newer generations of Thunderbolt as soon as available.

[143] Again, among the first was Promise Technology, who released updated Pegasus 2 versions of their R4 and R6 models along with an even larger R8 (8-drive) RAID unit, offering up to 32 TBs of storage.

As of 2019, the major OS vendors had not taken into account the variety of ways in which a malicious device could take advantage of complex interactions between multiple emulated peripherals, exposing subtle bugs and vulnerabilities.

Intel VT-d-based direct memory access (DMA) protection is a mandatory requirement for Thunderbolt 4 Host Certification.

They allow a malicious party to access all data stored in a computer, even if the device is locked, password-protected, and has an encrypted hard drive.

With a malicious firmware, the attacker can covertly disable Thunderbolt security, clone device identities, and proceed to use DMA to extract data.