SiPearl has begun delivering its Rhea1 processors to Bull for integration into Jupiter, Europe’s first exascale supercomputer. The move is significant because Jupiter’s record-setting booster currently relies on 24,000 US-made Nvidia superchips, while the new CPU partition will add European-designed silicon for workloads that GPUs cannot handle efficiently.

The Rhea1 is an 80-core Arm-based processor with 61 billion transistors, 64GB of HBM2e memory and 1.8TB/s of bandwidth, alongside four DDR5 channels. Jupiter’s CPU partition is expected to comprise 1,300 nodes and 2,600 processors, delivering about 5 petaflops—small beside the booster, but important for scientific applications and the EU’s digital-sovereignty ambitions; SiPearl’s newer Rhea2 chips are also planned for the Alice Recoque supercomputer.