StarTech has announced a Thunderbolt cable that is three metres long, the longest copper cable yet, which is available for backorder on the UK-based company's website for £56.99.

The number of options available for Mac users to buy Thunderbolt cables from outside Apple is growing, with companies announcing longer and competitively priced cables that will also work with upcoming Windows PCs with Thunderbolt ports.

The first Thunderbolt ports were introduced in Apple's Mac computers in February last year, but customers were earlier restricted to buying a $49 2m cable from Apple. The exclusivity broke when Elgato in April announced a 0.5m Thunderbolt cable for $59.

Kanex said yesterday that this week it would start shipping a 2m cable for $59.95. Sumitomo is already offering a 2m cable in Japan for ¥4,500 (£35). But Apple's Thunderbolt cable remains a cheaper option compared to Kanex and Sumitomo.

Thunderbolt is a high-speed connector technology that shuttles data between computers and peripherals. Co-developed by Apple and Intel, Thunderbolt offers data transfer speeds of up to 10 Gbps (gigabits per second), making it a faster alternative to USB 3.0. The companies claim a high-definition movie can be transferred from an external storage device to a laptop in less than 30 seconds. The technology also allows daisy-chaining up to five peripherals, so a longer cable run can make it easier to attach more devices to a single Thunderbolt port.

StarTech's 3m TBOLTMM3M cable will carry power, reducing the need for some peripherals such as storage devices to connect to power outlets. The three-foot cable will transfer data at the full 10Gbps over the cable.

The current Thunderbolt cables are based on copper, and faster optical cables are expected in the future. Sumitomo has shown a 20m optical cable, though it has not said when it will ship. While copper cables can carry power, optical cables cannot carry power and will require peripherals to connect to power outlets.

Lenovo, Acer and Asus have already announced laptops with Thunderbolt ports, though products are not yet available. The ports will also appear in ultrabooks, a form of thin-and-light laptops backed by Intel. Intel is soon expected to announce new chips based on the Ivy Bridge architecture for ultrabooks, which will better support the Thunderbolt interconnect.