02-01-2013, 10:01 AM
Fiberoptic Interconnect Opportunities in Supercomputers & High End Servers
1Fiberoptic Interconnect.pdf (Size: 1.78 MB / Downloads: 49)
Bandwidth Must Increase to Sustain System Performance
Moore’s Law (at the system performance level) no longer comes just from
improvements at the chip level
Parallel System performance increasingly comes from high-level interconnection of increasinglyparallel
chips & boxes
BW requirements must scale with System Performance, ~1B/FLOP (memory + network)
Requires exponential increases in communication bandwidth at all levels of the system
Inter-rack, backplane, card, chip,..
Summary and Take-Home points
Optics will play an increasing role in supercomputers as they approach the Exascale
ƒParallel optical interconnects are fast replacing copper cables today
nLow cost ($1/Gb/s) is critical to wider adoption, including optical backplane circa 2012
nSingle wavelength multimode VCSEL-based links appear to be lowest cost and lowest power ‡
Readily extensible to 10-20 Gb/s, perhaps 5mW/Gb/s
nPosition optics near logic for largest benefits
If cost can be further lowered, optically-enabled circuit cards based on polymer
waveguides will be deployed, circa 2012-2016
Optical board manufacturing “ecosystem” needs to evolve
Work today is single wavelength multimode VCSEL-based, could migrate to CWDM
Or even singlemode DWDM with cheap Si photonics
Optics directly on the chip for on- and off-chip global interconnects is a future
possibility
Drive is power savings for communications
Still at an early stage, basic building blocks being developed
Needs to be approached from a systems level, not individual devices