APPLICATIONS

By Uwe Harms - Munich, When analysing the Top500, looking at the high-end clusters, Quadrics is the network of choice in high-end computing. Three of the Top 5 machines use its fast QsNet as the system area network. Also in the IDC Balanced Rating Benchmark of Capability Computers from November 2002 Quadrics is top. Here 5 of the leading 15 systems use Quadrics QsNet, although IDC deleted the second, identical machine of Los Alamos National Lab. Thus one has to count 6 of the 16 systems. The Top500 Supercomputer List The November 2002 list shows three newcomer in the Top 5. Two ASCI Q AlphaServer SC at Los Alamos National Laboratory follow the NEC Earth Simulator, delivered by the new Hewlett-Packard company. Having a peak performance of 10 TeraFlop/s using 4096 processors (1.25 GHz) each, they run with 7.7 TeraFlop/s the Linpack Benchmark. The number 5 is installed by Linux NetworX and is based on Intel Xeon, 2.4 GHz. This machine at Lawrence Livermore National Lab has a peak performance of 11 TeraFlop/s and runs Rmax with 5.7 TeraFlop/s. All these computers use the fast Quadrics QSnet system area interconnect. Their Linpack performance, Rmax, sums up to 21 TFlop/s, the peak performance is nearly 33 TFlop/s. That means that these Quadrics systems reach a Linpack application performance of 65% of the peak. Within the Top10 there are another two computers with Quadrics QSnet. Then, with 5 machines, the aggregated Rmax reaches nearly 30 TFlop/s, the peak performance is 44 TFlop/s. The number 6 and 7 are based on Alphas again, the Pittsburgh Supercomputing Center (Dual-Rail QsNet) and the French Atomic Authority (Commissariat a l'Energie Atomique, CEA. Here the Rmax data are 4.5 and 4 TFlop/s, the peak is 6 TeraFlop/s and 5.1 TeraFlop/s respectively. Pittsburgh has 3016 processors, CEA 2560. They use the Quadrics SAN too. Hewlett-Packard delivered another two Intel Itanium 2 based clusters with the Quadrics interconnect. The British Petroleum Houston, rank 42, has 545 processors with a peak of 1.6 TeraFlop/s and an Rmax of 1.1 TeraFlop/s. The Pacific Northwest Laboratory (Dual-Rail QsNet) on rank 61 with 256 processors. They have a peak of 1 and an Rmax of .85 TeraFlop/s. Thus nearly all the extremely fast clusters in the Top 10 use the high-speed Quadrics QsNet, except nr. 8 which uses Myrinet. IDC Benchmark This November IDC published a revised IDC Benchmark list. Here, because of its better processor and scaling rating, the IBM ASCI White lies on rank 2, ahead the Hewlett-Packard ASCI Q machine. In their table only one ASCI Q is listed, as they put only one of an identical machine in their ranking. The machine got an IDC rating of 4.046 compared to 40.478 of the Earth Simulator. This means 10% of this NEC machine. The followers on rank 4, 2.914, and 5, 2.485, the Pittsburgh and the CEA computer. Because of a lower processor rating the Linux NetworX machine fall back on rank 9, 1.607. Nr. 11 in IDC is the other LANL computer with 1536 processors. As IDC publishes details, one can look at the total memory & Interconnect bandwidth. Here the Earth Simulator is clearly ahead with 184 320 GB/s, followed by the proprietary IBM switch, 9216. The LANL data is 8474, the PSC is 6239, the CEA is 5296, and the Linux NetworX system delivers a bandwidth of 4078 GB/s. Thus IDC paints the same picture that Quadrics QsNet based clusters are strong in the high-end category. http://www.top500.org http://www.idc.com/hpc