SiPearl’s home-built European Rhea CPU, intended to power HPC systems, has been delayed again. The first samples of the processor would not appear until 2025, at a time when all the technology on board will be obsolete.

SiPearl’s Rhea CPU has been pushed back to 2025. Only then will SiPearl begin distributing samples of the HPC processor, with general availability planned for an unspecified later date. The Rhea CPU is part of the European Processor Initiative to increase the EU’s HPC capabilities and was originally planned for 2023.

Outdated technology

By 2025, the efforts of SiPearl and the EU funds could be in vain. Finally, all of the key technological components on which the Rhea CPU is built are outdated.

• Rhea will feature 80 compute cores (instead of the originally planned 72) based on Arm Neoverse V1 designs. Neoverse V2 is already used by AWS and Google, among others, and next year Neoverse V3 will offer competition.
• The chip features a unique memory structure with four HBM2E stacks and a 256-bit DDR5 interface. This year HPC chips include HBM3 memory.
• SiPearl will bake the CPUs on a 7nm process from TSMC. 5nm is currently the norm and by the time Rhea is released, competing processors will move out of the 3nm band.

What about Jupiter?

Rhea1 is intended to pave the way for future HPC chips manufactured in Europe. The processor can still take on this pioneering role. Finally, SiPearl supports a broad ecosystem. All steps taken to introduce this chip will also support the introduction of next generations.

A first supercomputer with Rhea is also being planned. The impact on the Jupiter system that Eviden will build in Germany is unclear. The schedule for this system, scheduled for delivery this year, appears unfeasible.

Not a successful start

However, we cannot call the saga a success. The delay will undoubtedly reduce Rhea’s impact. In addition, the design is a bit watered down from the start.

Ultimately, the goal of the European Processor Initiative is for the EU to be able to compete with the US and Japan with its own chips. Arm, whose designs SiPearl adopts, is originally a British company that is now firmly in Japanese hands through its parent company Softbank. The license-related ecosystem is also less open than, for example, Risk-V.