As a member of the technical program committee for VTDC 2007 I present the following Call for Papers, please feel free to pass on the text version to others that you know who may have an interest in this workshop.
Tango, the new AMD Opteron cluster that’s getting built at VPAC to replace the now 4 year old Brecca is taking shape nicely!
The Victorian Partnership for Advanced Computing (VPAC) is looking for a Linux systems administrator to join our systems team working on grid computing.
Reporting to the ICI Operations Manager, you will be working primarily in a Linux systems administrator role with Grid toolkits such as Globus and VDT. You will be involved in a National Project to provide Grid Based Computing available across Australia. The ability to work with and support our end users (typically scientific researchers and software developers) is very important in this role. Some national and international travel will be involved.
So if you think that it sounds interesting then please and go read the job advert on the VPAC website, or at least tell a friend! 
Our new cluster has started arriving at VPAC, and this is what my office looks like after a big delivery yesterday..
Fortunately that’s only for a few days until Xenon Systems start racking the boxes!
At SC06 there was a panel discussion on the final day about whether the trend to more and more cores on a socket was going to be good or bad for HPC. The feeling was that because the fact that chip makers need to do something to make up for stagnating clock speeds coincided with having more and more blank space on the die as transistor sizes shrunk more cores was inevitable.
However, this puts all your memory on the wrong side of the pins from the cores, and HPC will (must) need to find a way to deal with it!
The presentations were really good and I was a bit sad that I couldn’t get enough notes as the session was packed and I was up near the back, but I’ve just found out that all the slides used are up on the web as PDF’s, courtesy of the most amiable Thomas Sterling, who chaired the session.
The most illuminuating HPC related quote was from the slides of Steve Scott talking about how RAM characteristics have changed over the years:
1979 -> 1999:
16000X density increase
640X uniform access BW increase
500X random access BW increase
25X less per-bit memory bandwidth
My favourite non-HPC quote is from Don Becker’s slides:
My nightmare: An 80 core consumer CPU means your web experience will be 79 3D animated ads roaming over your screen
Be afraid, be very afraid (on both grounds)..
Eugen Leitl has just posted on the Beowulf list a message with a link to a draft of a paper by Alfredo Buttari, Piotr Luszczek, Jakub Kurzak, Jack Dongarra and George Bosilca called A Rough Guide to Scientific Computing On the Playstation 3. It’s a 74 page PDF looking at the possibilities and problems with using the PS3 for scientific computing (there is already a PS3 Linux cluster at NCSU).
The introduction to the paper lets you know that this isn’t going to be easy..
As exciting as it may sound, using the PS3 for scientific computing is a bumpy ride. Parallel programming models for multi-core processors are in their infancy, and standardized APIs are not even on the horizon. As a result, presently, only hand-written code fully exploits the hardware capabilities of the CELL processor. Ultimately, the suitability of the PS3 platform for scientific computing is most heavily impaired by the devastating disproportion between the processing power of the processor and the crippling slowness of the interconnect, explained in detail in section 9.1. Nevertheless, the CELL processor is a revolutionary chip, delivering ground-breaking performance and now available in an affordable package. We hope that this rough guide will make the ride slightly less bumpy.
Of course, it’s unlikely you’re going to see the PS3 being used in production clusters anyway, so the interconnect shouldn’t be such a problem there..
The paper covers the hardware, Linux support and how to get it onto a PS3, programming methods and models, MPI, performance, etc. The paper isn’t complete as I write, but it is still a very interesting read. HPC folks will certainly want to read section 9.1 “Limitations of the PS 3 for Scientific Computing”, especially the part that says:
Double precision performance. Peak performance of double precision floating point arithmetic is a factor of 14 below the peak performance of single precision. Computations which demand full precision accuracy will see a peak performance of only 14 Gflop/s, unless mixed-precision approaches can be applied.
Well I’m happy to say that today I got the Request For Proposals (RFPs) out of the door for the proposed replacement of VPACs ageing Linux cluster Brecca (180 cores of 2.8GHz Intel Pentium 4 Xeon) and a significant amount of additional storage. Needless to say the new cluster must run Linux!
Please see the announcement on the VPAC systems blog for more information and copies of the RFPs.
This has been keeping my very busy recently and so I’m looking forward to a nice quiet break over Easter!
XmdS looks like an interesting package:
XMDS is a code generator that integrates equations. You write them down in human readable form in an XML file, and it goes away and writes and compiles a C++ program that integrates those equations as fast as it can possibly be done in your architecture.
Personally I thought it might be drawing a long bow to call XML “human readable”, but some of the examples aren’t too bad at all.
RMIT came back online at around 09:30, hopefully it will last!
VPAC systems are unreachable from the outside world as it appears that all RMIT networks failed at around 8am.
This means that the Linux Users of Victoria (LUV) server is also down as it is hosted at VPAC, so no LUV email or website for the moment.
The systems themselves are still functioning normally, just needs the RMIT ITS networks folks to track down the problem and fix it (good luck people!).
To quote Eugen Leitl on the Beowulf list..
Apropos of Cell, I presume most of you have seen http://moss.csc.ncsu.edu/~mueller/cluster/ps3/
Shame Cell isn’t very good at double precision floating point..
