Vienna Scientific Cluster 4 [Photo: Alexander Gigl/EDV-Design Informationstechnologie GmbH]
VSC-4 is a joint project of five Austrian universities – Vienna University of Technology, University of Vienna, University of Natural Resources and Life Sciences Vienna, Graz University of Technology and Innsbruck University – financially supported by the Federal Ministry of Education, Science and Research.
The new system consists of 790 water cooled nodes (Lenovo SD650), each with two Intel Skylake Platinum 8174 processors with 24 cores. The 700 standard nodes have a main memory of 96 GBytes, there are 78 fat nodes with 384 GBytes of main memory and 12 very fat nodes with 768 GBytes. Each node is also equipped with an SSD device of 480 GBytes, available as temporary storage during the runtime of a job.
The system is complemented with 10 login nodes and parallel file systems. Compute nodes, login nodes and file system nodes are interconnected with 100 Gbit/s OmniPath. The OmniPath network has a two-level fat-tree topology with an oversubscription of 2:1.
The compute nodes are directly water cooled allowing to use primary cooling water with a temperature in excess of 43 ℃, permitting year-round free cooling. Up to 90% of the energy will be removed by this high-temperature loop with the remainder being removed by air cooling. This permits a very reasonable energy foot-print.
A node reaches about 250 points in the SPECrate2017 Floating Point benchmark, which is about 5 times the performance of a VSC-3 node (16 cores). Looking at the Linpack benchmark, a single VSC-4 node reaches about 3 TFlop/s, about 10 times the performance of a VSC-3 node at slightly less than 300 GFlop/s. A large part of this floating-point performance comes from the two AVX-512 units per core, each allowing for 8 fused-multiply-add instructions per cycle.
Another system with 8174 processors, another impressive achievement by Lenovo.