The introduction of optical interconnections to internode connections
in the RWC-1 massively parallel computer testbed, which was designed t
o demonstrate fundamental internode communications, and uses eight pai
rs of 12-channel compact optical modules, has enabled 48-b parallel da
ta transmission at 100 MHz (600-MB/s throughput), to be achieved in fi
bers up to 20-m long. The latency caused by the additional delay time
due to OE/EO conversion in module is only 15 ns. This high throughput,
over a long transmission length, along with the compactness, and low
latency of optical interconnections make these interconnections applic
able to massively parallel computing. The introduction of optical inte
rconnections will do much to alleviate the communication bottlenecks i
n the computer systems.