Expanse will be a Dell integrated compute cluster, with AMD Rome processors, interconnected with Mellanox HDR InfiniBand in a hybrid fat-tree topology. There are 728 compute nodes, each with two 64-core AMD EPYC 7742 (Rome) processors for a total of 93,184 cores. They will feature 1TB of NVMe storage and 256GB of DRAM per node. Full bisection bandwidth will be available at rack level (56 nodes) with HDR100 connectivity to each node. HDR200 switches are used at the rack level and there will be 3:1 oversubscription cross-rack. In addition, Expanse also has four 2 TB large memory nodes. The system will also feature 12PB of Lustre based performance storage (140GB/s aggregate), and 7PB of Ceph based object storage.None