Hi Peter and all,
Yes, that sound like me too. The earlier discussion's resolution you
mention was to mount the disk as 'async'. I am not absolutely
certain, but I understand that async mounted drives do not write as
they go but delay until a timeout occurs or certain size of date write
accumulates. This certainly fits with my observation that writing a
large file to the disk mounted as async initially goes very fast then
slows down as the write process becomes continous.
For my application, I am writing a continous stream of critical
scientific data to the disk, and, because the system may power down
with only a few seconds notice, I cannot guarantee giving the async
mounted disk time to write the caches before I lose power. Thus, I
need to use the sync method.
Given that the SD card interface does not appear to have more than
8-10kB/s continious write speed, does anyone have any figure for the
TS-RF2-CF compact flash write speed and its demands on the CPU?
Thanks,
Hamish
--- In "PeterElliot" <> wrote:
>
> --- In "hamishavery" <hamishavery@> wrote:
> >
> > Killing all unused applications and mounting only one of my three
> EXT2
> > partitions on the SD card (as sync), I get a write speed to the card
> > of around 8kB/s (from bonnie++) with a Kingston 256MB SD card, and
> at
> > best 16kB/s with a 512MB no-brand 60X SD card. Furthermore, the
> > processor loading reported by bonnie++ is 99%. I get around 800kB/s
> > doing the same test but writing to a network drive (NFS) at around
> 3% CPU.
> >
> > I would like to know if anyone else has experienced this problem or
> > has any solutions. Is it normal or is my system somehow wrong?
>
> I've noticed slow ftping to the SDcard. I only get 10k/s downloading
> to my 7300 via ethernet - which just happens to be the same speed as
> using zmodem via serial...
>
> There has been dissusion on this list previously on this subject
> (from memory), but I can't remember any resolution to the issue.
>
> PJE
>
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