Results & Impact

Sustained upstream contribution, June 2025 – August 2026

76 commits landed
152 PRs reviewed
216 review comments

Evaluation that changed upstream code

Testing of the proposed Open MPI strong-progress implementation on two LLNL systems found a performance regression and a crash; both reported upstream, the crash now fixed.

Resilient training without checkpointing

ReCoVer keeps a per-iteration invariant so that failures are absorbed rather than rolled back, removing the checkpoint-restart tax from large-model pretraining. A. K. Maurya; under review, NeurIPS 2026

Disaggregated inference, characterized inside the engine

Two shipped vLLM KV-cache connectors — NCCL push and NIXL pull — instrumented under one replayed trace (panel below).

Both move 652 MB per request, but past a crossover near 45–60 req/min push’s prefill queue grows 4.4× faster, and 98% of pull transfers sit at the paged allocator’s 16 KiB descriptor floor — under 8% of a Slingshot rail.

Both need non-blocking completion and efficient movement of thousands of small, non-contiguous device regions — exactly what one-sided RMA with notification provides. under review, PMBS@SC 2026

OpenCCL: runs real software unmodified

NVIDIA’s own all-reduce benchmark ran to full correctness over OpenCCL on H100 nodes — within a node and across two nodes over InfiniBand — with no source changes.

Behind it, a normative openccl.h at NCCL 2.23.4 API compliance and a design record as large as the code: 65 documents, ∼19k lines, against ∼19k lines of implementation.

Early results; performance characterization in progress.

Phase-level power and energy attribution across 512 GPUs and 480 APUs on Frontier and Portage — the measurement basis for the energy behavior of AI phases in Year 2.

ISC High Performance 2026