This is nonsense. In microcomputer architecture there is something known as the radius of control, which is bounded by the distance that can be traversed by a signal from a processing unit to memory and back. That feedback time is, even in some hypothetical all-optical computer, limited by the speed of light. Light travels one foot per nanosecond or thereabouts. So if you had wafer-scale optical computing you could support radius of control at a cycle time of about 1GHz. This is a hard limit -- very hard.
I've attacked this computation limit as directly as just about anyone with an analog mutex crossbar circuit that keeps main memory access on chip <http://jimbowery.blogspot.com/2013/04/a-circuit-minimizing-multicore-shared.html>. This is critical because as soon as you go off chip you suffer orders of magnitude slowdown in your primary control cycle. Architectures that attempt to hide this problem with lots of processors accessing local stores in parallel are drunks looking for their keys under the lamp post. On Mon, Jan 26, 2015 at 6:22 PM, Rich Murray <rmfor...@gmail.com> wrote: > doubling speed every 2 years for decades more, Intel silicon photonics now > revolutionizing data centers, Michael Kassner: Rich Murray 2015.01.26 > http://rmforall.blogspot.com/2015/01/doubling-speed-every-2-years-for.html > > > [ See also: > > exponential information technology 1890-2014 10exp17 more MIPS per > constant 2004 dollar in 124 years, Luke Muehlhauser, Machine Intelligence > Research Institute 2014.05.12: Rich Murray 2014.12.27 > > http://rmforall.blogspot.com/2014/12/exponential-information-technology-1890.html > > > since 1890, increase by 10 times every 7.3 years -- > > since 1950 -- 2014 = 64 years, with about 10exp13 times more = > 10,000,000,000,000 times more per device, from vacuum tubes to multicore > processors -- increase by 10 times every 5 years per constant 2004 dollar. > > > CSICON -- Murray's Law -- Eternal Exponential Expansion of Science: Rich > Murray 1997.04.05, 2001.06.22, 2011.01.03 > > http://rmforall.blogspot.com/2011/01/csicon-murrays-law-eternal-exponential.html > http://groups.yahoo.com/group/rmforall/message/102 ] > > > > http://www.techrepublic.com/article/silicon-photonics-will-revolutionize-data-centers-in-2015/ > > > NETWORKING <http://www.techrepublic.com/topic/networking/> > Silicon photonics will revolutionize data centers in 2015 > > By Michael Kassner <http://www.techrepublic.com/search/?a=michael+kassner> > January 23, 2015, 11:23 AM PST > > - Email Alert > > <http://www.techrepublic.com/article/silicon-photonics-will-revolutionize-data-centers-in-2015/?tag=nl.e101&s_cid=e101&ttag=e101&ftag=TRE684d531#> > - RSS <http://www.techrepublic.com/rssfeeds/topic/networking/> > > > - Comments > > <http://www.techrepublic.com/article/silicon-photonics-will-revolutionize-data-centers-in-2015/?tag=nl.e101&s_cid=e101&ttag=e101&ftag=TRE684d531#postComments> > - Save > - Facebook0 > - Twitter0 > - Linkedin0 > - > - More > > Data centers are morphing into computing singularities, albeit large ones. > Silicon photonics will hasten that process. The reason why begins with > Moore's Law. > > [image: siliconphotonics012815.jpg] > Image courtesy of Intel > > Gordon Moore's prediction known as Moore's Law > <http://www.intel.com/content/www/us/en/history/museum-gordon-moore-law.html> > -- > "The number of transistors incorporated in a chip will approximately double > every 24 months." -- has been uncanny in its accuracy since he made it in > April 1965. That didn't stop pundits from saying Moore's Law > <http://www.computerhistory.org/semiconductor/timeline/1965-Moore.html> had > a nice run, but like all good things, it was coming to an end. The pundits' > prediction was erroneous, thanks to Intel (the company Moore co-founded). > The reason is light, or more accurately photons. > The problem photons overcome > > [image: gordonmooreintel.png] > Gordon Moore > Image courtesy of Intel > Moore's Law requires scientists and engineers to continually figure out > how to pack larger quantities of transistors and support circuitry into > chips. It's a challenge, but not as difficult as figuring out what to do > about the by-products of shoving electricity through an ever-more dense > population of chips: heat buildup, current leakage, and crosstalk between > adjacent wire traces. > > Multi-core technology > <https://software.intel.com/en-us/articles/frequently-asked-questions-intel-multi-core-processor-architecture> > breathed > new life into Moore's Law, but only for a short time. Using copper wires to > transmit the digital information becomes the limiting factor. This MIT > Technology Review 2005 article > <http://www.technologyreview.com/featuredstory/404358/intels-breakthrough/>explains > why copper wires were no longer good enough. "The problem is that > electrical pulses traveling through a copper wire encounter electrical > resistance, which degrades the information they carry," states author > Robert Service. "As a result, data bits traveling through copper must be > spaced far enough apart and move slowly enough that devices on the other > end of the wire can pick them up." > > That challenge becomes evident when walking through a data center, because > most, if not all, copper-based Ethernet runs have been replaced with fiber > optics. Using *existing* fiber-optic technology will not help Moore's Law > -- that requires a new technology called the silicon laser > <http://www.intel.com/content/dam/www/public/us/en/documents/intel-research/Silicon-Laser_WhitePaper.pdf> > . > Fast forward to 2009 > > Intel's Photonics Technology Laboratory > <http://www.intel.com/content/www/us/en/research/intel-labs-silicon-photonics-research.html> > in > 2009 mastered the silicon laser. "We have done all the things that skeptics > said we could not," mentions Intel Fellow Mario Paniccia > <http://newsroom.intel.com/community/intel_newsroom/bios?n=Mario%20J.%20Paniccia&f=Fellows> > in > this SPIE article <http://optics.org/article/40732>. "We have got beyond > the proof-of-principle stage. Now we're putting it all together so that > Moore's Law can extend for decades into the future." > > The article goes on to explain how Paniccia and his team created > high-speed silicon modulators and photodetectors so small they will fit on > chips. The slide below depicts the two devices and their interconnections. > > [image: intelsilicondevices012315.png] > Image courtesy of Intel > > Innovations since 2009 > > Since 2009, Intel introduced: > > - 50 Gigabit per second silicon-based optical data connection > > <http://www.intel.com/content/dam/www/public/us/en/documents/intel-research/Intel_SiliconPhotonics50gLink_FINAL.pdf>. > The world's first silicon-based photonics link running at 50 Gbps, using > technology that combines fiber-optic attributes with silicon manufacturing > processes. > - Photonics technology operating at 100 gigabits per second > > <http://www.intel.com/content/www/us/en/research/intel-labs-idf2013-justin-rattner.html>. > This is an integrated module including silicon modulators, detectors, > waveguides, and circuitry. > - Optical PCI Express server > > <http://www.intel.com/content/www/us/en/research/intel-labs-silicon-photonics-optical-pci-express-server.html>. > Fujitsu and Intel showcased new silicon-photonic connections that allow PCI > cards to be moved off the main board, which creates shared pools of compute > and storage, enhances cooling flexibility, and lowers costs by moving hot > components farther apart. > > Moving data centers to a single computing entity > > One by-product of securing Moore's Law for the foreseeable future will be > the complete redesign of data centers. Racks and racks of heat-spewing > servers will be replaced by efficient, discrete components that are > connected using silicon photonics. > > For example, in 2013, Intel and Facebook released information > <http://newsroom.intel.com/community/intel_newsroom/blog/2013/01/16/intel-facebook-collaborate-on-future-data-center-rack-technologies> > about > using silicon photonics at the rack level. "Intel and Facebook are > collaborating on a new disaggregated, rack-scale server architecture that > enables independent upgrading of compute, network, and storage subsystems > that will define the future of mega-datacenter designs for the next > decade," said Justin Rattner, Intel's then CTO. "The disaggregated rack > architecture includes Intel's new photonic architecture...that enables > fewer cables, increased bandwidth, farther reach and extreme power > efficiency compared to today's copper based interconnects." > > Disaggregated refers to separating compute, storage, networking, and power > distribution resources into modules housed in the rack. "Traditionally, a > server within a rack would each have its own group of resources," according > to the press release. "When disaggregated, resource types can be grouped > together and distributed throughout the rack, improving upgradability, > flexibility and reliability while lowering costs." > > So look for a two-pronged attack on copper in the data center. First, what > Intel considers "pluggable" -- its MXC connector > <http://www.intel.com/content/www/us/en/research/intel-labs-silicon-photonics-mxc-connector.html> > and > new technology will revamp connections even as short as five inches. > Second, embedded technology using silicon photonics will supply high-speed > optical links to and from the processor. > > I have written that data-center technologists are striving to morph data > centers into a virtual and physical singularity. It appears that silicon > photonics will help them reach their goal. > > Automatically subscribe to TechRepublic's Data Centers newsletter. > Subscribe > > <http://www.techrepublic.com/search/?a=michael+kassner> > About Michael Kassner > > Information is my field...Writing is my passion...Coupling the two is my > mission. > > - Full Bio > > <http://www.techrepublic.com/article/silicon-photonics-will-revolutionize-data-centers-in-2015/?tag=nl.e101&s_cid=e101&ttag=e101&ftag=TRE684d531#modal-bio> > - Contact > > <http://www.techrepublic.com/article/silicon-photonics-will-revolutionize-data-centers-in-2015/?tag=nl.e101&s_cid=e101&ttag=e101&ftag=TRE684d531#author-contact> > - See all of Michael's content > <http://www.techrepublic.com/search/?a=michael+kassner> > - Google+ <https://plus.google.com/108264533098601176125/?rel=author> > > > > >
