↳ CAF WATCHER // CONTINUOUS PHYSICAL AUDIT LEDGER

RIKEN & Fujitsu (Fugaku) Grade A+

Japan's sovereign exascale supercomputing monument: ARM A64FX architectural mastery and national resilience · Category: Supercomputing & National HPC

Executive Physical Feasibility & Delivery Audit

Institutional Baseline: CAF Watcher evaluates stated accelerator capabilities against empirical physical reality (interconnection queues, electrical substations, liquid cooling heat transfer, and optical network fabrics). Missing public evidence is classified as unknown—it is never treated as zero capacity. Operator telemetry strengthens assessments, but participation is never mandatory.

CAF INTERVAL
[0.63 – 0.96]
DELIVERY GAP SCORE
12 pts
OPERATING POWER
0.05 GW
vs 0.1 GW announced
EVIDENCE CONFIDENCE
MEDIUM (65%)

Physical Coupling Pillars

Power & Grid Substrate (E): 96/100. Powered by a dedicated 77kV underground transmission line from Kansai Electric Power, engineered to maintain power continuity even during magnitude 7+ earthquakes.
Thermal Dissipation & CDU Limits (T): 95/100. Every single A64FX processor is cooled by water flowing through micro-machined copper channels at 15°C inlet temperature, dissipating 95%+ of heat to water.
Cluster Topology & Optical Fabric (N): 97/100. Tofu-D network embeds routing directly into the CPU packaging, creating a 6D torus topology with fault-tolerant multi-path communication across 432 racks.
Silicon & Advanced Packaging (O): 88/100. Pioneered on-package HBM2 memory for general-purpose CPUs, achieving 1,024 GB/s memory bandwidth per node.

Attributable Public Evidence Ledger

Every claim evaluated by CAF Watcher is grounded in public regulatory filings, utility interconnection disclosures, environmental permitting reports, or peer-reviewed engineering papers.