slow USB HD

[Tito]

On Saturday 15 December 2007 19:30:00 Hauke Fuhrmann wrote:
> Hi there,
> 
> I'm rather a busybox noob, so I hope to find some help here:
> 
> I use busybox on my Siemens Gigaset settopbox together with VDR. This
> works very fine, but unfortunately I seem to be the only user with this
> combination that experiences a very slow USB HD performance.
> 
> Strange thing is, that the HD is running at a Windows PC perfectly with
> ~25MB/s.
> 
> benchmarks with dd result in the following:
> 
> # time dd if=/dev/zero of=/media/LAUFWERK_G/out.test bs=1024 count=100000
> 100000+0 records in
> 100000+0 records out
> real    1m 49.80s
> user    0m 2.30s
> sys     0m 34.70s
> # time dd if=/media/LAUFWERK_G/out.test of=/dev/null
> 200000+0 records in
> 200000+0 records out
> real    0m 46.59s
> user    0m 4.08s
> sys     0m 23.64s
> 
> which is about 4MB/s and worse.
> 
> mount results these mount options:
> /dev/sda1 on /var/media/LAUFWERK_G type vfat
> (rw,noatime,nodiratime,nosuid,nodev)
> Hence it's not synchronized.
> 
> Any Idea how I could debug this further? ~4MB/s is bigger than low-speed
> USB, so it does not seem to be a problem of the wrong USB driver...
> 
> I would also say that it's no problem of CPU performance, because there is
> some community of users with the same HW and don't experiencing this
> problem (but they don't have an idea what's wrong here, either).
> 
> So this mailing list is my last hope to get things going...
> 
> Cheers,
> Hauke

Hi,
maybe you can query the drive with hdparm or sdparm
to see how it is set up (DMA, Power Management, Acoustic Management) .
Checking with lsmod if EHCI, OHCI or UHCI kernel module is used
could give some information too.
Looking at you kernel config file can give also some info
(is the kernel misconfigured? Have you compiled it yourself?
which version?...)
The lsusb command  could give you more info about the usb device.
All in all I suspect that this has not much to do with busybox tough....


Ciao,
Tito