Slashdot Mirror
Top 500 Supercomputer List Released
sundling writes "The heavily anticipated Top 500 Supercomputer list has been released. There is a Sevenfold increase in AMD Opteron processors on the list. Two sections of an IBM prototype took spots in the top 10 and the famous Apple cluster didn't make the list, because it was out of service for hardware upgrades. When complete, the new IBM cluster is sure to take the top spot from the Earth Simulator."
At least 5 of the top 10 systems are running Linux, starting at number two with Thunder at the Lawrence Livermore National Laboratory. The others are IBM BlueGene/L clusters at places #4 and #8, Tungsten at NCSA at #5, MPP2 at Pacific Northwest National Laboratory at #9, and probably also the Dawning 4000A at the Shanghai Supercomputer Center as #10, though I'm not 100% sure about this last one.
It's like deja vu all over again.
Did they mention why myrinet and infiniband are heat sensitive? I've used myrinet before, and did not encounter any problems with it, though I was not using 1U dual-CPU systems. (just a bad idea in general) A myrinet card includes a pretty high-clocked ASIC that runs warm for a network card, but is nothing compared to most graphics cards these days.
Blue Gene is an amazingly simple, and crafty design, with efficiency at its heart. I'm not sure that it will be as successful as the IBM marketing machine claims it will, but it's exciting none-the-less.
The trend in CPUs, over the last ten years or so, has been to maximally fill long, wide super-scalar pipelines. The Power4 has half a dozen execution units and a 15 stage pipeline, running at 1.7 ghz. To keep that full, one has to have exceptional branch prediction, huge caches, and superb compilers, and tons of memory bandwidth.
The Blue Gene approach is to have fewer, shallower, lower-clocked pipelines, but lots of CPUs. Their peak speed is a quarter of the top CPU designs, but their real speed is half of the big guns. Since they are using today's chip technology to implement yesterday's chip designs, they use little power, and are very inexpensive. Since IBM has cleverly integrated all the communications networks and memory controllers, you only need three components in the system: CPUs, RAM chips, and passive circuit boards - plastic and copper. (Yeah, I'm sure there is other stuff, but not much)
The design is not revolutionary, it's a fairly intuitive evolution of the Paragon, or the T3E. This sort of system may not be perfect for every task, but will excell at the sorts of tasks that already work well on big clusters. That, and it will likely be very cost effective.