I would like to point-out that The Opportunities and Challenges of Exascale Computing has some interesting information in the section "The Hardware Challenges" Less recent (2008) but much more interesting with regard to hardware is ExaScale Computing Study: Technology Challenges in Achieving Exascale Systems, Peter Kogge, Editor & Study Lead The 2008 report convinced me that a large amount of hardware improvements are needed so I've remained curious as to whether the changes would come to pass from commercial mass-market COTS development.
A useful collection of reports can be found at http://science.energy.gov/ascr/news-and-resources/program-documents/ To clarify, I'm not recommending the use of cell-phone computers, rather, for a question after talk I asked a knowledgable person in the field of exascale what was currectly driving technological advances towards Exascale hardware and he indicated that circuit improvements for cell phones would drive the low-power circuit development. Personally, I'm not convinced. With regard to attracting government funding, many of the reports such as "The Opportunities and Challenges of Exascale Computing" seem to be primarily sales brochures oriented towards that goal, IMHO. With regard to cache coherency, Eugen Leitl wrote "There also cannot be any such thing as a global memory, unless you want it to be slow and spend a lot of silicon real estate to make multiple writes to the same location consistent." It is a very interesting question as to what can be done with global shared memory without requiring coherency. For some algorithms global atomic operations are needed but not necessarily cache coherence. Supercomputer manufacturers are building ever more sophisticated networks, on the other hand, one of my interests in the Beowulf mailing list is to hear about global memory improvements available with COTS hardware so researchers are not dependent on the few supercomputers with specialized interconnect hardware. Regards, Alan -- Alan Scheinine 200 Georgann Dr., Apt. E6 Vicksburg, MS 39180 Email: [email protected] Mobile phone: 225 288 4176 http://www.flickr.com/photos/ascheinine _______________________________________________ Beowulf mailing list, [email protected] sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
