Modern HPC systems must be designed considering different parameters, which include cost, performance, and throughput, as well as non-functional properties, such as power/energy consumption and reliability. This paper describes the work performed and the results achieved by the partners of the Italian National Research Center for HPC, Big Data and Quantum Computing in the frame of the sub-project dealing with Future HPC architectures and solutions. The work in this subproject focused on advanced design and monitoring techniques for devising energy- and power-efficient, reliable parallel architectures based on open standards (e.g., RISC-V) and design space exploration techniques and tools. This paper provides a summary of the achieved results and developed products stemming from the activities of the different partners.

The N -body problem is a classical computational challenge that involves integrating the motion equations of a system of interacting bodies. This problem is computationally demanding and, as power consumption becomes a critical issue in computing systems, increasing the energy efficiency of solutions is essential. To address this, we use FPGA accelerators to implement the acceleration computation, the most demanding part of the integration algorithm. FPGAs are known for their low power requirements and high internal parallelism, but they traditionally require hardware programming skills. With High-Level Synthesis (HLS) now well established, we leverage the AMD Vitis HLS toolchain to implement the acceleration computation for the N-body problem. After analyzing the various forms of parallelism at different levels of granularity in the acceleration computation, we design a parallel architecture, implemented on an FPGA using the HLS flow. The speed and energy efficiency of our solution are compared against high-end CPU implementations, showing substantial improvements. Our FPGA implementation achieves 30.4 GPair/s and $697\ \mathrm{MPair} / \mathrm{s} / \mathrm{W}$, significantly outperforming previous FPGA and CPU solutions in both speed and power consumption.

The TEXTAROSSA project aims to bridge the technology gaps that exascale computing systems will face in the near future in order to overcome their performance and energy efficiency challenges. This project provides solutions for improved energy efficiency and thermal control, seamless integration of heterogeneous accelerators in HPC multi-node platforms, and new arithmetic methods. Challenges are tacked through a co-design approach to heterogeneous HPC solutions, supported by the integration and extension of HW and SW IPs, programming models, and tools derived from European research.

Writing good code for FPGA is a challenge “per se”, but also running already existing and optimized FPGA kernels often requires writing specific “host side” code and some target hardware knowledge to achieve good performances. In this work, we describe a FastFlow extension supporting seamless off loading of tasks to FPGA, once an FPGA kernel is available. In particular, we show how kernels implemented in Vitis and running on XILINX Alveo FPGA boards may be integrated to implement “normal” parallel stages (pipeline stages, map/farm workers) in a structured parallel FastFlow computation. Experimental results are shown, demonstrating the feasibility of the approach.

To achieve high performance and high energy efficiency on near-future exascale computing systems, three key technology gaps needs to be bridged. These gaps include: energy efficiency and thermal control; extreme computation efficiency via HW acceleration and new arithmetics; methods and tools for seamless integration of reconfigurable accelerators in heterogeneous HPC multi-node platforms. TEXTAROSSA aims at tackling this gap through a co-design approach to heterogeneous HPC solutions, supported by the integration and extension of HW and SW IPs, programming models and tools derived from European research.

The paper presents a research work concerned with the integrate assessment of seismic vulnerability and energy performance of existing buildings at urban scale through BIM (Building Information Modelling).At the urban scale, it is often required to manage large set of buildings, for which it is not possible to perform detailed investigation, modeling and analysis. At this scale of analysis, an additional issue is the coexistence of different building components and performance requirements (structural safety, functional and aesthetic efficiency, energy efficiency, and so on), which often have a dynamic interaction.For this reason, the modeling approach should be able to encounter this complexity and provide the interaction of multiple expertise, in order to provide optimal solutions of the critical issues and vulnerability of buildings.Within this context, the research has proposed and tested a framework structured through a suitable BIM model finalized to implementation of integrated simplified evaluation procedure of seismic vulnerability and energy performance at urban scale.The objective is to provide an innovative tool for the performance-based assessment in a context of uncertainty and incomplete information typical of the urban scale analysis.The proposed approach allows to manage information from different source and quick investigations concerns structural safety and energy efficiency, and it has been focused on the case study of “Fiera del Levante”, a trade fair district extending over 280.000 m2, composed by several buildings aged from 1929 to 2012, that host about thirty events (including international fair shows) throughout the year as well as conferences and/or exhibitions.

This paper presents a building automation strategy for natural ventilation control and reducing building energy consumption. An on-off control is proposed in order to manage the windows opening and realize a natural ventilation flow guaranteeing indoor thermal comfort. The control logic is based on activation thresholds that are optimized to reduce the discomfort for overheating and undercooling. In particular, the temperature comfort range dynamically varies according to the adaptive thermal comfort theory. To this aim, a co-simulation architecture is proposed: the thermal building behavior and ventilation dynamics are simulated by TRNFLOW within the TRNSYS software and a Particle Swarm Optimization algorithm is employed to optimize the thresholds of windows opening. A case study focusing on a residential building situated in the Mediterranean climatic context is presented: the thermal comfort analysis shows that the optimized control logic significantly reduces the overheating discomfort.

The Integrated Tokamak Modelling Task Force (ITM-TF) is developing an infrastructure where the validation needs, as being formulated in terms of multi-device data access and detailed physics comparisons aiming for inclusion of synthetic diagnostics in the simulation chain, are key components. A device independent approach to data transport and a standardized approach to data management (data structures, naming, and access) is being developed in order to allow cross validation between different fusion devices using a single toolset. The effort is focused on ITER plasmas and ITER scenario development on current fusion device. The modeling tools are, however, aimed for general use and can be promoted in other areas of modelling as well. Extensive work has already gone into the development of standardized descriptions of the data (Consistent Physical Objects) providing initial steps towards a complete fusion modelling ontology. The longer term aim is a complete simulation platform which is expected to last and be extended in different ways for the coming 30 years. The technical underpinning is therefore of vital importance. In particular, the platform needs to be extensible and open-ended to be able to take full advantage of not only today's most advanced technologies but also be able to marshal future developments. A full level comprehensive prediction of ITER physics rapidly becomes expensive in terms of computing resources and may cover a range of computing paradigms. The simulation framework therefore needs to be able to use both grid and HPC computing facilities. Hence, data access and code coupling technologies are required to be available for a heterogeneous, possibly distributed, environment. The developments in this area are pursued in a separate project - EUFORIA (EU Fusion for ITER Applications). The current status of ITM-TF and EUFORIA is presented and discussed.