France's KAIROS Leads June 2026 Green500 Rankings

France's KAIROS supercomputer tops the June 2026 Green500 list with 73.28 GFLOPS/Watt efficiency, as Nvidia GH200 chips dominate the top four.

France's KAIROS system has secured the top spot in the June 2026 Green500 rankings, achieving an energy efficiency of 73.28 GFLOPS/Watt. While leading in efficiency, the system dropped from rank 422 to 446 in the Top500 computing power list. The Green500 top 10 remained unchanged from November 2025, with the four most efficient systems utilizing Nvidia GH200 superchips. Following KAIROS are France's ROMEO-2025 at 70.91 GFLOPS/Watt and Germany's Levante GPU at 69.43 GFLOPS/Watt. Other top performers include the UK's Isambard-AI phase 1, Germany's Otus and Capella, South Korea's SSC-24, Poland's Helios GPU, and France's AMD Ouranos. The USA's Portage system, powered by AMD 4th Gen Epyc processors and Instinct MI300A accelerators, rounds out the top ten with 66.28 GFLOPS/Watt.