Rolling Round-Robin Rate: Standard Heterogeneous Throughput for SPEC CPU

Abstract

SPEC CPU has long provided a common foundation for comparing processor, compiler, memory-system, and platform performance. Its multi-copy SPECrate mode measures homogeneous throughput by running many copies of the same benchmark at once. That mode remains valuable, but modern cloud and server systems commonly run heterogeneous collections of jobs whose interactions are shaped by shared caches, memory bandwidth, power management, operating-system scheduling, and noisy neighbors. SPEC CPU 2026 introduces Rolling Round-Robin Rate (RRR), an exhibition run style that uses the existing rate suites to generate deterministic heterogeneous multiprogrammed workloads. This paper describes RRR as a benchmark methodology and proposes a SPEC-like scoring model for future RRR reporting: compute per-benchmark average throughput and coefficient of variation from per-copy ratios, compute a SPEC-style geometric mean for each copy across the suite, and average that population of copy geomeans to form a suite score with its own coefficient of variation. RRR therefore preserves the familiar SPEC throughput tradition while exposing richer information about variability, interference, and heterogeneous-system behavior.

6 pages, 1 figure, Presented at the 2026 IEEE International Symposium on Workload Characterization (IISWC 2026), Boulder, Colorado