User documentation for the PLEIADES cluster at the University of Wuppertal


The cluster consists of 268 workernodes with 17152 Cores in total. Additionally, there are 5 GPU nodes with 8 NVidia A100 GPUs and 128 Cores each. 931 TB of parallel storage are provided with BeeGFS.

Node Types


The CPU Worker nodes wn21[001-268] are connected to each other and to the BeeGFS servers via InfiniBand and ethernet. All GPU nodes (gpu21[001-005]) are in a separate InfiniBand network and access BeeGFS via ethernet. The login nodes are currently connected to all other nodes via ethernet.

Hardware and network layout of PLEIADES

Network Performance for Computing

For network intensive computing tasks between multiple nodes (e.g. MPI), the InfiniBand (IB) network should be used in any case. Our InfiniBand network topology is a non-blocking fat tree, which allows for full bandwidth between all nodes:

InfiniBand network topology

Up to 40 nodes are connected with 100 Gbit/s (HDR100) to each leaf switch. All leaf switches have 40 channels with 200 Gbit/s (HDR) to the spine switches. As a consequence, it is not necessary to keep multi-node jobs physically close, since the bandwidth can be maintained throughout the whole network. Your multi-node jobs likely perform well with any wn21xxx involved.

A MPI job using our ethernet network, on the other, could saturate parts of or the whole network. For ethernet, the topology is similar, but with only 10 Gbit/s to each node and much fewer leaf-spine connections.