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Atos and the CEA launch EXA1 supercomputer – the most powerful & energy-efficient HPC system in Europe based on General Purpose CPUs

​Atos and the CEA’s Military Applications Division (CEA/DAM) today announce the first partition of “EXA1”, a supercomputer developed together based on Atos’ BullSequana XH2000 architecture, which is among the world’s 500 most powerful machines. Reaching 14th position in the TOP500 ranking, “CEA-HF” is the most powerful supercomputer and most energy-efficient supercomputer based on general purpose CPUs in Europe. It has 12,960 AMD processors, this is 829,440 computer processor cores, making it the largest ever installed HPC system based on general purpose CPUs worldwide. It has a computing power of 23.2 petaflops and a competitive power consumption of 4.96 MegaWatts.

Published on 18 November 2021
EXA1 features Atos’ 100% highly efficient water-cooled patented Direct Liquid Cooling (DLC) solution, which uses streams of lukewarm water to cool the machine, providing the most advanced PUE~1 (Power Usage Effectiveness) on the market. This feature enables the CEA/DAM to effectively control its energy consumption and reduce costs, and at the same time benefitting from processors with the very highest power requirements.
CEA-HF is interconnected by the second generation of Atos’ BullSequana eXascale Interconnect (BXI v2). Thanks to the full hardware offload of the communications mechanism in the BXI V2, the processor’s usage is optimized, avoiding interferences. The offload boosts the communication performance of HPC applications, enabling CPUs to be fully dedicated to computational tasks while communications are independently managed by the BXI V2. As a result, CEA-HF delivers high communication performance considering bandwidth, latencies, or message rates. 

Vincenzo SALVETTI, Director of the CEA’s Military Applications Division, says:

Developing such a high-level supercomputer is  essential for some of the defence programs that we implement at the CEA/DAM. To reach this capacity, technological breakthroughs are needed – such as maintaining low levels of energy consumption, while ensuring that the huge volumes of data produced by increasingly precise simulations can be effectively processed. I am proud that the long-term R&D partnership between Atos and the CEA/DAM allows us to achieve this new major milestone for our program, and leverage CEA/DAM’s innovation capabilities”. 

Pierre BARNABÉ, Acting Co-CEO of Atos and Head of Atos’ Global Big Data & Security Division, adds: 

We’re thrilled that our BullSequana supercomputer continues to boost Europe's scientific excellence and industrial strength, and we are extremely pleased to support CEA in bringing their research and innovation one step further with EXA1”. 
As long-standing partners, Atos and CEA have been collaborating since 2004. EXA1 is the 4th supercomputer that the two companies have developed together, crowning the expertise acquired by the CEA and Atos HPC team.
Atos is a Spotlight Sponsor at this year’s SC’21 that takes place in St. Louis (US) from 15-18 November 2021 and will host a live webinar on “The incessant pursuit in the Exascale Journey” and virtual booth sessions. More details -

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