Experts such as Andy Bechtolsheim, founder of the switch vendor Arista Networks, have said silicon photonics will be key to driving a sluggish market for 100G links. Mellanox's Shainer took a more conservative view, even though its Kotura acquisition was one of the first to show 100G capabilities.
"Silicon photonics is a sexy topic, but it will be only a part of 100G, not everything," Shainer said. Mellanox's products will also support copper and more traditional optics options.
The copper version will have shorter reach than current 14G products that extend less than five meters, but he would not predict an exact length. As an optical alternative to silicon photonics, the company will use VCSELs from a source he would not name.
The Kotura approach uses wavelength division multiplexing; some others use parallel single-mode optics. All the competitors are using CMOS for silicon photonics, except the startup OneChip, which uses indium phosphide.
Intel hopes to gain an additional edge by integrating a high-speed interconnect into future server processors. The link will presumably provide unique features when coupled with Intel's silicon photonics.
Shainer said such an approach will force tradeoffs such as limiting the topology and applications of the link. "There will be clear reasons for a separate interconnect chip, [and] some customers prefer not to use an integrated SoC fabric."
Mellanox has carved out a growing piece of the high-performance networking business by expanding from chips and cards into full systems and designing products that use both Infiniband and Ethernet. Nevertheless, it has come under pressure as 100G and low-latency Ethernet standards have enabled systems that match Infiniband products.
In addition, much of the focus for big datacenters and carriers has turned to building networks that are simpler to manage using virtualization and software-defined networking. Much of that work is focused on Ethernet, rather than Infiniband. For its part, Mellanox has created an Ethernet initiative to drive open-source efforts and bolster interoperability of core Ethernet features such as routing and boot loaders.
Mellanox's roadmap shows its earlier acquisition of Voltaire, which put the company in the system-level switch business.