speed at which Meta ran production RoCE on the back-end with PFC only and no DCQCN, relying on receiver-driven admission in the collective library
400Gobserved
| 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 | Historical 400G deployment: DCQCN was removed after default settings degraded performance; PFC was the only flow control, with receiver-driven admission co-designed into the collective library and CTS packets prioritized at the switches. Meta's 2026 MetaRoCE transport runs without PFC. |
| As of | 2024-08 |
| Source | Engineering at Meta (RoCE at scale) |
| Review | checking…review by 2027-08-05 · standard cadence |
| Recorded changes | last 2026-10-16 · 2 revisions tracked |
| Claim id | speed-at-which-meta-ran-production-roce-pfc |
Where the guide uses it
← Full numbers register — every date-stamped figure in the guide, with revision history.