SATA link utilisation

SATA link utilisation: from line rate to delivered megabytes

Pick a SATA generation, set the protocol overhead and the drive's own sequential speed, and see where the bottleneck sits. The default numbers are the classic SATA 3.0 SSD: 550 MB/s on a 600 MB/s link.

SATA generation (line rate)

Drive sequential speed: 550 MB/s

Protocol overhead (FIS, CRC, primitives): 8%

Line rate (what the copper carries, 8b/10b coded)

Payload after 8/10 decoding (blue) — protocol overhead eats the orange slice

Delivered throughput (green) vs the payload ceiling (red tick)