Notes on two presentations by Gordon Bell ca. 1998
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From: Robert Myers on 31 Jan 2010 19:24 Three R Myers prizes to G Bell for the second presentation. Others may be interested in different things from that which got my attention. http://research.microsoft.com/en-us/um/people/gbell/ISHPC99.ppt (My comments are in parentheses) Bell-Hillis Bet slide (this business is really about massive single- image egos) ARPA-funded product development failed (doesn't mention effect of DoD directive about COTS, though) ASCI: DOE-funded product purchases creates competition (HAHAHAHAHA) First efforts in startups... all failed. (Left off the role of the DoE in assuring continuing domination by IBM.) Supercomputing is for the large and rich (Is that a statement of fact or a definition? My desktop will run circles around the supercomputers I used to use and that I still think of as the genuine article.) Beowulf, shrink wrap cluters (no negative comments, but who is Gordon Bell being paid by... a mfr of shrink-wrap software) Virtuous Economic Cycle that drives the PC industry (should have monoculture, not standards in the center). (Even a picture of Gordon Bell with an NT (!) cluster) You should /not/ focus NSF CS Research on parallelism. I can barely write a correct sequential program." Don Knuth 1987 (to Gbell... of course) Non-U.S. users continue to use vectors (no AF captains to drive things back to familiar territory--PC's--in Europe) Interconnecton networks log(p) continue to be the challenge (unless you are using a router chip per node, which scales as p/n, where n is the number of processors per node) Russian Elbrus E2K Micro What is the Processor Architecture (slam dunk for vectors, good reason to close down CS departments wholesale) It's memory bandwidth, cache prediction, inter-communication, and overall variation (G Bell gets an R Myers prize for getting it). Execution efficiencies of Community Climate Model Version 2 (why this fluid mechanicist has such contempt for the Top 500 list). Are US users being denied tools? (well, no. they have been sold on stupid tools) Do larger scale, faster, longer run times, increase problem insight and not just total flop or flops (second R Myers prize to G Bell in one presentation) Challenge to funders: Is the cost justified? (THREE R Myers prizes to G Bell in one presentation). Robert.
From: nedbrek on 31 Jan 2010 20:24 Hello all, "Robert Myers" <rbmyersusa(a)gmail.com> wrote in message news:ea2c8491-2403-499f-94dd-1fb3d37cd8f5(a)o28g2000yqh.googlegroups.com... > Three R Myers prizes to G Bell for the second presentation. Others > may be interested in different things from that which got my > attention. > > http://research.microsoft.com/en-us/um/people/gbell/ISHPC99.ppt > > What is the Processor Architecture (slam dunk for vectors, good reason > to close down CS departments wholesale) Are you saying vectors are good or bad? And is it short vectors (SSE) or long vectors (Arana)? Ned
From: Robert Myers on 31 Jan 2010 21:04 On Jan 31, 8:24 pm, "nedbrek" <nedb...(a)yahoo.com> wrote: > Hello all, > > "Robert Myers" <rbmyers...(a)gmail.com> wrote in message > > news:ea2c8491-2403-499f-94dd-1fb3d37cd8f5(a)o28g2000yqh.googlegroups.com... > > > Three R Myers prizes to G Bell for the second presentation. Others > > may be interested in different things from that which got my > > attention. > > >http://research.microsoft.com/en-us/um/people/gbell/ISHPC99.ppt > > > What is the Processor Architecture (slam dunk for vectors, good reason > > to close down CS departments wholesale) > > Are you saying vectors are good or bad? And is it short vectors (SSE) or > long vectors (Arana)? > That was my comment on Gordon Bell's slide, which summarized two artificially-opposed points of view. I like his false dichotomy, though. CS departments and much of the discussion here have focused on approaches that are essentially dead-ends--academic masturbation for those with CS degrees. SSE is better than nothing, but my long-term bet is on streaming architectures, which are a generalization of Cray-style vector parallelism. NO MORE NEW LANGUAGES. Asm only, if necessary, but figure out how to expand the space that can be handled with a streaming paradigm. Fortunately, GPGPU will save us from all of the expensive mistakes the US has been making ever since Seymour left the scene. That's my hope, anyway. Robert.
From: Terje Mathisen "terje.mathisen at on 1 Feb 2010 02:04 Robert Myers wrote: > SSE is better than nothing, but my long-term bet is on streaming > architectures, which are a generalization of Cray-style vector > parallelism. > > NO MORE NEW LANGUAGES. Asm only, if necessary, but figure out how to > expand the space that can be handled with a streaming paradigm. > Fortunately, GPGPU will save us from all of the expensive mistakes the > US has been making ever since Seymour left the scene. That's my hope, > anyway. Pure streaming architectures, even in the form of GPGPU, are dead. There is absolutely no way to get enough bandwidth for a pure streaming core, you have to have caches. What will determine your actual throughput is how well you can partition your problem into parts that can be reused at least a few times (i.e. cached) and those that cannot and have to be streamed by instead. The crucial part of streaming is simply that it makes it explicit that these inputs should not and must not pollute the caches! Terje -- - <Terje.Mathisen at tmsw.no> "almost all programming can be viewed as an exercise in caching"
From: nedbrek on 1 Feb 2010 07:54
Hello all, "Terje Mathisen" <"terje.mathisen at tmsw.no"> wrote in message news:20bi37-lic2.ln1(a)ntp.tmsw.no... > Robert Myers wrote: >> SSE is better than nothing, but my long-term bet is on streaming >> architectures, which are a generalization of Cray-style vector >> parallelism. > > >> Fortunately, GPGPU will save us from all of the expensive mistakes the >> US has been making ever since Seymour left the scene. That's my hope, >> anyway. > > Pure streaming architectures, even in the form of GPGPU, are dead. Terje is right. Even GPUs are moving to short vectors (for ray tracing). Long vectors are just so specialized, there is no market for them. The super guys are riding the coat tails of product oriented towards consumers. That's why clusters are so important. They're the only way to get more power. Long vectors are "embarassingly parallel", so you can use just about any method to exploit them. Ned |