NetBSD 6.1.5/amd64 and USB poor performance

[tlaronde%polynum.com@localhost]

Hello,

I have NetBSD 6.1.5 on a amd64 with USB 3.0 ports.

When writing files to an external USB (3.0) connected disk, using
ntfs-3g, the write performance is abyssal : it is only USB 1.0 (12
Mbps or 1.5MB/s).

From the manual pages (ehci(4)), NetBSD 6.x supports only USB 2.0 via
ehci(4). The ehci connectors have also companion controllers (ohci(4)
and uhci(4)) that support USB 1.0.

My kernel config had only ehci support. Nonetheless, the write
performance is only USB 1.0.

The disk is attached with umass.

Is the problem with umass? With ntfs-3g ? (but for what reason shall the
performance of a filesystem driver depend on the way the device is
connected?) Problem with librefuse ?

Any clue would be welcomed.

TIA,
-- 
        Thierry Laronde <tlaronde +AT+ polynum +dot+ com>
                     http://www.kergis.com/
                     http://www.arts-po.fr/
Key fingerprint = 0FF7 E906 FBAF FE95 FD89  250D 52B1 AE95 6006 F40C