IBM switches on the light for high-speed data transfers
IBM’s new silicon photonics chip will compete against a similar Intel technology.
IIBM is ready to light up data transfers over long distances between computers with a new chip that could spell the end for slower electrical wiring. After a decade of research, IBM has developed a new silicon photonics chip that can transfer data at aggregate speeds of 100Gb/s (bits per second). In tests, the reference chip could transfer data using pulses of light over a distance of 2km.
Light can transfer data faster than copper cables, which are used in data centres to link storage, networking and servers in data centres. The silicon photonics chip could aid in introducing high-bandwidth optical fibre connections in future generations of supercomputers and servers, especially with vast amounts of data moving between computing resources.
IBM is developing the technology with the intent to push it in data centres, and it won’t be in PCs or handhelds anytime soon, said Wilfried Haensch, senior manager of IBM’s Silicon Photonics Group.
The silicon photonics technology could also fundamentally change the way servers are implemented in data centres by decoupling the processing, memory and storage units into separate boxes. The design could help applications run faster and reduce component costs by consolidating fans and power supplies.
There is also demand for more computing power in servers with applications such as analytics, machine learning and big data. Optical connections could help dozens of processors communicate on a server rack, making it easier to break up processes over multiple resources, according to Richard Doherty, research director at The Envisioneering Group.
Optical connections could make servers much like storage drives, which can be easily hot-swapped depending on processing needs in data centres, Doherty said.
Light is already being used for longdistance data transfers over telecom networks, but that technology can be expensive. Optical cables are also available for the Thunderbolt interconnect, which is used in Macs and PCs for high-speed data transfers with external peripherals.
IBM’s silicon photonics technology is meant for shorter distances, and is cheaper than optical technology used in telecom networks, Haensch argued.
Intel has also made silicon photonics chips for data centres, but has struggled to ship them on time. IBM may not be the first with a silicon photonics chip, but its technology is more viable and less complicated than Intel’s, Doherty said.
IBM’s chip is “more manufacturable” as it has a simple integrated silicon structure and is cheaper to make, while Intel’s structure needs additional physical components, according to Doherty.
Intel, however, said that its optical components are integrated and have testing and cost advantages.
The chips are also fundamentally different in how they transfer data, but have their cost and performance advantages. IBM’s chip transfers data over a single fibre using four different ‘colours’ as channels, while Intel’s technology could scale faster with more fibres added to optical cables, Doherty said.
Intel has built MXC optical cables that can have up to 64 fibres, with each fibre transferring data at 25Gb/s. But adding fibres can be expensive, and IBM’s singlefibre implementations could be cheaper and meet many speed and distance requirements in data centres, Doherty said. IBM declined to comment on when the silicon photonics chips would reach the market.