"da0: 40.000MB/s transfers" What was rationale behind pegging USB 2.0 at 40MB/s?

Wojciech Puchar wojtek at wojtek.tensor.gdynia.pl
Mon Jul 23 07:41:20 UTC 2012

> And USB 2.0 hard limit is 60MB/s.
i have never seen USB 2.0 exceeding 35MB/s write and 40MB/s read.

even when connecting SATA disk over USB-SATA bridge.

60MB/s is wire speed. USB have enormous protocol overhead.

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