It's a technology that has been worked upon tirelessly by both IBM, Intel and many others. On-chip optical interconnects promise to offer high-performance at low-cost when it comes to transferring data from one chip, or even a server, to another.
Currently, optical interconnection is handled by discrete add-on cards, typically sitting on something like a PCI Express bus. This approach incurs several levels of overhead: the cost of the PCB manufacturing, parts and card development, the actual data overhead of PCI Express transfer and use of available PCI Express lanes/slots and the optical componentry itself is generally quite costly and, this is all before considering the significant mark-up optical technology has seen up until now.
IBM believes it has cracked it, however, by successfully manufacturing the first 90nm CMOS chips with nano-scale optical interconnects built-in. By integrating the technology into a processor's standard build process, the cost of adding these interconnects is negligible, with chips now capable of communicating more efficiently and cheaply, straight from the die.
The firm is claiming that each of its 'optical channels' can transmit around 25Gbps and that multiple channels can be multiplexed into a single fibre to reach bandwidths one the scale of Terabytes per second. This technology promises to significantly improve the viability of multi-chip systems and multi-server data-centres, we only hope that IBM makes any patents available to all for a reasonable cost.
