Meta production RoCE fabric overprovisioning (under-subscription): rail-switch uplink capacity first doubled to run 1:2 under-subscribed against ECMP flow collisions, later trimmed to 1:1.125 — deliberately not 1:1, to keep buffer for up to two link failures
1:2 → 1:1.125observed
| 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. |
|---|---|
| As of | 2024-08 |
| Source | Engineering at Meta |
| Review | checking…review by 2026-09-26 · fast cadence |
| Recorded changes | last 2026-08-24 · 2 revisions tracked |
| Claim id | meta-rtsw-under-subscription-ratio |
Where the guide uses it
← Full numbers register — every date-stamped figure in the guide, with revision history.