Re: [gentoo-user] usb1 performance out of usb2 external HD

[Richard Fish <bigfish@asmallpond.org>]

On 1/16/06, Iain Buchanan <iaindb@netspace.net.au> wrote:
> On Mon, 2006-01-16 at 06:40 -0700, Richard Fish wrote:
> > On 1/15/06, Iain Buchanan <iaindb@netspace.net.au> wrote:
> > > Hi all,
> > > $ sudo hdparm -tT /dev/sdd
> > >
> > > /dev/sdd:
> > >  Timing cached reads:   3640 MB in  2.00 seconds = 1820.28 MB/sec
> > >  Timing buffered disk reads:   30 MB in  3.13 seconds =   9.60 MB/sec
> > >
> > > 9.6 is pretty slow! I should be able to get at least double that...
>
> actually, I should be able to get 4x that...

No, you won't.  The max I've ever seen any USB drive run at is about
30MB/sec, even when the same drive installed internally will run at
65MB/sec.  My best 2.5" case and drive will pump about 25MB/sec.

> > Please post the dmesg output from plugging in the drive.
>
> Note, there are 4 LUNS on this device, the first 3 are card readers ,so
> they show with no media (no drive or partitions), the fourth (sdd) is
> the ide drive.

Ok, I've never used one of these combination devices.  I'm a little
concerned, because the maximum throughput of most media readers is
about 10MB/sec...so hoping this is not a limitation of the chipset.

> relevant dmesg:

Looks normal...

>  sdd: sdd1 sdd2 sdd3 sdd4 < sdd5 sdd6 sdd7 sdd8 sdd9 sdd10 sdd11 >

Damn, and I thought I made a lot of volumes.... ;->

> $ zgrep USB /proc/config.gz | grep -v "^#"
> CONFIG_USB_IRDA=m
> CONFIG_BT_HCIUSB=m
> CONFIG_BT_HCIUSB_SCO=y
> CONFIG_BT_HCIBFUSB=m
> CONFIG_USB_ARCH_HAS_HCD=y
> CONFIG_USB_ARCH_HAS_OHCI=y
> CONFIG_USB=m
> CONFIG_USB_DEVICEFS=y
> CONFIG_USB_EHCI_HCD=m
> CONFIG_USB_UHCI_HCD=m
> CONFIG_USB_PRINTER=m
> CONFIG_USB_STORAGE=m

I think you need to turn on some of the options under USB Mass Storage
support.  Particularly

CONFIG_USB_STORAGE_FREECOM=y

but I don't think there is any harm in turning all of them on...it is
very likely that one of these will give you the best performance.

-Richard

-- 
gentoo-user@gentoo.org mailing list