Definition

YottaScale Index (YSI)

A framework for describing progress toward yotta-scale compute capability using transparent dimensions such as performance, efficiency, scalability, and reliability.

The YottaScale Index (YSI) is a structured way to summarize how close a computing system, platform, or ecosystem is to achieving yotta-scale capability—commonly understood as order-of-magnitude compute at or approaching 1024 operations per second (depending on workload definition).

Rather than treating yotta-scale as a single threshold, YSI expresses readiness across multiple dimensions that must advance together for yotta-scale capability to be practical, repeatable, and sustainable.

Purpose

YSI exists to support clear communication about “yotta-scale” progress without requiring a single vendor benchmark or a single hardware definition. The index can be used to:

  • Compare architectures or system designs at a high level
  • Track progress over time using consistent dimensions
  • Separate peak capability from deployable, reliable capability
  • Encourage transparent assumptions (workload, precision, power, scaling method)

Core Dimensions

1) Compute Throughput

Achieved operations per second under a defined workload profile (e.g., dense math, sparse math, AI training/inference). Must specify precision (FP64/FP32/FP16/INT8, etc.) and measurement method.

2) Energy Efficiency

Performance per watt at scale, including cooling and infrastructure overhead (where applicable). Distinguishes lab peak from sustained operational efficiency.

3) Scalability & Interconnect

How well performance grows with added nodes/accelerators, including network bandwidth, latency, topology constraints, and synchronization overhead.

4) Memory & Data Movement

The ability to feed compute with data: memory capacity, bandwidth, hierarchy design, and the cost of moving data across the system.

5) Reliability & Fault Tolerance

Error rates, recovery behavior, checkpointing overhead, and operational stability at very large scale. Yotta-scale systems must assume component failure as normal.

6) Practical Deployability

Supply chain feasibility, manageability, cost profile, and repeatability across environments. Separates “one-off demo” from “deployable class of system.”

How YSI Can Be Expressed

YSI is intentionally flexible. Common representations include:

  • Profile vector (dimension scores presented side-by-side)
  • Weighted composite score (when a governance group defines weights)
  • Maturity bands (e.g., Concept → Prototype → Pilot → Deployable)

Any published YSI value should include the workload definition and scoring rubric used.

Scope Notes

  • YSI is not a vendor benchmark and does not prescribe a single test suite.
  • “Yotta-scale” may be defined differently across domains; YSI requires the definition to be stated.
  • YSI is compatible with HPC, AI, and hybrid workloads, provided assumptions are declared.