Re: usb 3.0 thumb drive speed limit

[Marat N.Afanasyev]

Florian Ermisch wrote:

Am 2. Januar 2017 10:59:49 MEZ, schrieb "Marat N.Afanasyev" <ama...@li.ru>:

Ian Smith wrote:

On Mon, 2 Jan 2017 11:27:49 +0300, Marat N.Afanasyev wrote:
   > I wonder is there a speed limit on usb 3.0? I've bought
   >
   > ugen0.4: <SanDisk> at usbus0
   > umass2 on uhub7
   > umass2: <SanDisk Extreme, class 0/0, rev 2.10/0.10, addr 4> on

usbus0

   > da2 at umass-sim2 bus 2 scbus9 target 0 lun 0
   > da2: <SanDisk Extreme 0001> Removable Direct Access SPC-4 SCSI

device

   > da2: Serial Number AA010808161609220143
   > da2: 40.000MB/s transfers
   > da2: 59840MB (122552320 512 byte sectors)
   > da2: quirks=0x2<NO_6_BYTE>
   >
   > that claims 'Up to 245 MBytes/sec read speed'
   >
   > and dd shows:
   >
   > % dd if=/dev/da2 of=/dev/null bs=1m count=1000
   > 1000+0 records in
   > 1000+0 records out
   > 1048576000 bytes transferred in 25.688997 secs (40818098

bytes/sec)

   >
   > why we have such a limit?

Seems you've plugged it into a USB 2 port, not USB 3

At least you're getting full USB 2 performance (40MB/s)

Check if you have one or more USB 3 ports with 'dmesg | grep xhci'

cheers, Ian

afair, single usb 2.0 device can be as fast as 240 Mbits/sec, not 320
Mbits/sec:

% dd if=/dev/da2 of=/dev/null bs=1m count=1000
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 34.026227 secs (30816699 bytes/sec)

it's the same drive in usb 2.0 port

And I do have usb 3.0:

% grep xhci /var/run/dmesg.boot
xhci0: <XHCI (generic) USB 3.0 controller> mem 0xfeaf8000-0xfeafffff
irq
17 at device 0.0 on pci5
xhci0: 64 bytes context size, 64-bit DMA
usbus0 on xhci0
xhci0: <XHCI (generic) USB 3.0 controller> mem 0xfeaf8000-0xfeafffff
irq
17 at device 0.0 on pci5
xhci0: 64 bytes context size, 64-bit DMA
usbus0 on xhci0

and I tried this thumb drive is in usb 3.0 port first, of course.

Are you running 10.x or 11.0?

When was running 10.1 I only got
~27 MB/s out of each of my two
external HDDs connected to the
same USB3 port (two disk enclosure,
speed according to `zpool iostat -v`
AFAIR).
They also attached as high-speed
devices.
Some time after upgrading to the
than current 11-CURRENT I've
noticed kernel messages mentioning
400 MB/s instead of 40 MB/s and
quite an improvement in throughput.

May be a quirk in the driver for your
paricular XHCI chip.

Regards, Florian
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11.0

I think that i have somehow buggy addon card :(

--
SY, Marat

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