A Scalable Server Architecture for Next-Generation Heterogeneous Compute Clusters

Increasing the energy efficiency of today's high-performance computing systems requires new approaches that go beyond homogeneous architectures, which primarily target maximum performance per node. Heterogeneous architectures that can be tailored towards the specific needs of a particular application are a promising alternative to state-of-the-art server systems. In this paper, we present a novel highly-scalable server architecture that seamlessly integrates variable combinations of general purpose CPUs, embedded CPUs, FPGAs, and GPUs. Embedded CPUs based on the latest ARM Cortex-A15 devices with integrated embedded GPUs are combined with FPGA-based reconfigurable SoCs, which can be used for application-specific hardware acceleration. A dedicated monitoring network enables continuous control and fine-grained observation of all relevant system parameters. Communication between the compute nodes is established by a flexible multi-level interconnect that can be adapted to various Ethernet and Infiniband standards. The communication facilities are further enhanced by direct high-bandwidth, low-latency links between the embedded FPGA-based reconfigurable SoCs.