GPU SMs consumed by a reduction after composing NVLink-SHARP + IB-SHARP in NCCL 2.27
~16 → ≤6 SMsobserved
| Value kind | observed — Reported measurements, counts, and specifications keep the precision and scope stated by their source; an exact specification is not treated as a range. |
|---|---|
| Scope | NVIDIA figure for AllGather and ReduceScatter in NCCL 2.27: ring implementations can use 16 or more SMs, and NVLink SHARP plus IB SHARP reduce this to 6 or fewer. |
| As of | 2025-07 |
| Source | NVIDIA Developer (NCCL 2.27); SHARP in-network computing |
| Review | checking…review by 2027-04-16 · standard cadence |
| Recorded changes | last 2026-10-16 · 2 revisions tracked |
| Claim id | gpu-sms-consumed-by-a-reduction-after-composing |
Where the guide uses it
← Full numbers register — every date-stamped figure in the guide, with revision history.