X520 live as the product NIC: rate buckets re-keyed to read time (one shared clock, one commit per drained batch) with the backward smear as a settled window — each completed bucket enters once, donates excess to the nearest earlier deficits once, locks for display when nothing later can refill it (per-sample recompute double-counted excess and read >20G on a 20G wire); timestamp machinery deleted (ts.go, SO_TIMESTAMPING, rx_filter=ALL check) after the audit confirmed the buckets were its sole consumer; testDriver ixgbe; RollBall mailbox hardened against orphaned-command completions (never sample status before a poll gap, value from the same block read, devad/reg echo required — a killed session's 7.60 read answered a PHY ID as 0x0006); full hardware pass: 20.00G flat both directions, zero errors, ECD 42m, SNR +7.4dB

docs/nics/README.md

@@ -8,7 +8,7 @@ A NIC is usable for module diagnostics only if the **host** can master the modul
 
 ## The timestamp requirement is dissolved
 
-All-packet hardware RX timestamps existed for one consumer — bucketing received frames by arrival time so the displayed rate stayed honest under host read-jitter. The smoothed-bucket plan ([x520](x520/README.md)) computes the rate from read-time buckets with a backward excess-fill instead, and every fault verdict comes from per-frame sequence/CRC accounting, never the rate. With that, the capability that disqualified the X520 — and the only thing the firmware-managed NICs offered over it — is no longer required (pending the audit that the rate buckets were the stamps' sole consumer). Raw-L2 steering was never a hard requirement either (encap acceptable).
+All-packet hardware RX timestamps existed for one consumer — bucketing received frames by arrival time so the displayed rate stayed honest under host read-jitter. The smoothed-bucket plan ([x520](x520/README.md)) computes the rate from read-time buckets with a backward excess-fill instead, and every fault verdict comes from per-frame sequence/CRC accounting, never the rate. The audit confirmed the rate buckets were the stamps' sole consumer, and the committed tree implements the plan; the capability that disqualified the X520 — and the only thing the firmware-managed NICs offered over it — is not required. Raw-L2 steering was never a hard requirement either (encap acceptable).
 
 ## Comparison