SanDisk write speeds

QNX Newsgroups (Archives) qdn.public.qnx4
1

Hi all,

We are using the SanDisk CompactFlash cards on our P5x little board
running QNX 4.25. We’ve noticed a large decrease in write performance
in the larger and newer SanDisk cards we’ve purchased recently (192MB,
256MB AND Ultra 256MB). Interestingly, older OEM versions of the 192MB
seem fine, but we can’t get these anymore.

I need to run some diagnostic type utilites on these disks and I would
like to use QNX instead of DOS (to prevent having to install DOS or
Win98 on these flashcards). Does anyone have any ideas on how to
perform sequential read/write tests under QNX? Anyone know if hdparm
from linux is or can be ported to QNX?

Thanks,
Rob

2

Rob Davidson <rdavidson@softwareremodeling.com> wrote:

Does anyone have any ideas on how to perform sequential read/write
tests under QNX?

Both “iozone” and “bonnie” are available from the QUICS software download
“http://quics.qnx.com/cgi-bin/dir_find.cgi?/usr/free”

3

Rob,

I found the same problem, and called them up. The story: ALL sandisk PC
cards and compact flash cards have been changed to a different flash
technology. I can’t remember which way they moved because it seemed
irrelevant.

You will find the change affecting you with different card sizes depending
on manufacturing schedules and distributor turnover.

The newer ones and older ones cannot be told apart except by the
manufacturing codes on the side edge.

The new ones are apparently optimized for megapixel camera files for which
they are supposed to be an improvement, but they can be slow for small files
like I was writing. The read speed is supposed to be unaffected.

So theoretically your read/write test will depend heavily on your file size.

Incidentally, I am told that the SanDisk “Ultra” flashcards would also have
small-file performance problems.

Other brands might work differently for you. I have been scouting around
for another manufacturer who is willing to publish their endurance
management specs, but so far I have found nobody. I would love to hear
suggestions, if anybody knows.

=Dave

“Rob Davidson” <rdavidson@softwareremodeling.com> wrote in message
news:3C910061.5060905@softwareremodeling.com…

Hi all,

We are using the SanDisk CompactFlash cards on our P5x little board
running QNX 4.25. We’ve noticed a large decrease in write performance
in the larger and newer SanDisk cards we’ve purchased recently (192MB,
256MB AND Ultra 256MB). Interestingly, older OEM versions of the 192MB
seem fine, but we can’t get these anymore.

I need to run some diagnostic type utilites on these disks and I would
like to use QNX instead of DOS (to prevent having to install DOS or
Win98 on these flashcards). Does anyone have any ideas on how to
perform sequential read/write tests under QNX? Anyone know if hdparm
from linux is or can be ported to QNX?

Thanks,
Rob

4

Thanks for the info. I will test based on smaller file sizes. So far
I’ve found that the Lexar Media 256MB 16x card has performance much like
the older SanDisk cards we used. I’m sticking to 256MB because that is
what our application requires, so I don’t know about larger ones. You
are right about the Ultra SanDisk, it has the same performance issues.
Only the Lexar seems to work well so far, but our client is concerned
about other problems we might find later using a different manufacturer.

Rob


Dave Lees wrote:

Rob,

I found the same problem, and called them up. The story: ALL sandisk PC
cards and compact flash cards have been changed to a different flash
technology. I can’t remember which way they moved because it seemed
irrelevant.

You will find the change affecting you with different card sizes depending
on manufacturing schedules and distributor turnover.

The newer ones and older ones cannot be told apart except by the
manufacturing codes on the side edge.

The new ones are apparently optimized for megapixel camera files for which
they are supposed to be an improvement, but they can be slow for small files
like I was writing. The read speed is supposed to be unaffected.

So theoretically your read/write test will depend heavily on your file size.

Incidentally, I am told that the SanDisk “Ultra” flashcards would also have
small-file performance problems.

Other brands might work differently for you. I have been scouting around
for another manufacturer who is willing to publish their endurance
management specs, but so far I have found nobody. I would love to hear
suggestions, if anybody knows.

=Dave

“Rob Davidson” <> rdavidson@softwareremodeling.com> > wrote in message
news:> 3C910061.5060905@softwareremodeling.com> …

Hi all,

We are using the SanDisk CompactFlash cards on our P5x little board
running QNX 4.25. We’ve noticed a large decrease in write performance
in the larger and newer SanDisk cards we’ve purchased recently (192MB,
256MB AND Ultra 256MB). Interestingly, older OEM versions of the 192MB
seem fine, but we can’t get these anymore.

I need to run some diagnostic type utilites on these disks and I would
like to use QNX instead of DOS (to prevent having to install DOS or
Win98 on these flashcards). Does anyone have any ideas on how to
perform sequential read/write tests under QNX? Anyone know if hdparm
from linux is or can be ported to QNX?

Thanks,
Rob
\

5

Rob,

Do you know if the endurance specs are available?
e.g… SanDisk publishes guaranteed additional 1 percent spare sectors, each
sector retired after 300,000 write cycles. They do not use wear leveling.
So I can estimate the minimum time a given capacity card will last.

=Dave

“Rob Davidson” <rdavidson@softwareremodeling.com> wrote in message
news:3C91F6E7.40204@softwareremodeling.com…

Thanks for the info. I will test based on smaller file sizes. So far
I’ve found that the Lexar Media 256MB 16x card has performance much like
the older SanDisk cards we used. I’m sticking to 256MB because that is
what our application requires, so I don’t know about larger ones. You
are right about the Ultra SanDisk, it has the same performance issues.
Only the Lexar seems to work well so far, but our client is concerned
about other problems we might find later using a different manufacturer.

Rob


Dave Lees wrote:

Rob,

I found the same problem, and called them up. The story: ALL sandisk
PC
cards and compact flash cards have been changed to a different flash
technology. I can’t remember which way they moved because it seemed
irrelevant.

You will find the change affecting you with different card sizes
depending
on manufacturing schedules and distributor turnover.

The newer ones and older ones cannot be told apart except by the
manufacturing codes on the side edge.

The new ones are apparently optimized for megapixel camera files for
which
they are supposed to be an improvement, but they can be slow for small
files
like I was writing. The read speed is supposed to be unaffected.

So theoretically your read/write test will depend heavily on your file
size.

Incidentally, I am told that the SanDisk “Ultra” flashcards would also
have
small-file performance problems.

Other brands might work differently for you. I have been scouting
around
for another manufacturer who is willing to publish their endurance
management specs, but so far I have found nobody. I would love to hear
suggestions, if anybody knows.

=Dave

“Rob Davidson” <> rdavidson@softwareremodeling.com> > wrote in message
news:> 3C910061.5060905@softwareremodeling.com> …

Hi all,

We are using the SanDisk CompactFlash cards on our P5x little board
running QNX 4.25. We’ve noticed a large decrease in write performance
in the larger and newer SanDisk cards we’ve purchased recently (192MB,
256MB AND Ultra 256MB). Interestingly, older OEM versions of the 192MB
seem fine, but we can’t get these anymore.

I need to run some diagnostic type utilites on these disks and I would
like to use QNX instead of DOS (to prevent having to install DOS or
Win98 on these flashcards). Does anyone have any ideas on how to
perform sequential read/write tests under QNX? Anyone know if hdparm
from linux is or can be ported to QNX?

Thanks,
Rob

\

6

Sorry for not responding sooner, I hadn’t got back to the group in a
while. No, I don’t know about this spec for Lexar but need to find out
now that you mention it. We assumed the same as SanDisk but that’s not
good to do. I’ll have to call them or contact them to find out myself.
Please let me know if you’ve found out already.

Rob


Dave Lees wrote:

Rob,

Do you know if the endurance specs are available?
e.g… SanDisk publishes guaranteed additional 1 percent spare sectors, each
sector retired after 300,000 write cycles. They do not use wear leveling.
So I can estimate the minimum time a given capacity card will last.

=Dave

“Rob Davidson” <> rdavidson@softwareremodeling.com> > wrote in message
news:> 3C91F6E7.40204@softwareremodeling.com> …

Thanks for the info. I will test based on smaller file sizes. So far
I’ve found that the Lexar Media 256MB 16x card has performance much like
the older SanDisk cards we used. I’m sticking to 256MB because that is
what our application requires, so I don’t know about larger ones. You
are right about the Ultra SanDisk, it has the same performance issues.
Only the Lexar seems to work well so far, but our client is concerned
about other problems we might find later using a different manufacturer.

Rob


Dave Lees wrote:


Rob,

I found the same problem, and called them up. The story: ALL sandisk

PC

cards and compact flash cards have been changed to a different flash
technology. I can’t remember which way they moved because it seemed
irrelevant.

You will find the change affecting you with different card sizes

depending

on manufacturing schedules and distributor turnover.

The newer ones and older ones cannot be told apart except by the
manufacturing codes on the side edge.

The new ones are apparently optimized for megapixel camera files for

which

they are supposed to be an improvement, but they can be slow for small

files

like I was writing. The read speed is supposed to be unaffected.

So theoretically your read/write test will depend heavily on your file

size.

Incidentally, I am told that the SanDisk “Ultra” flashcards would also

have

small-file performance problems.

Other brands might work differently for you. I have been scouting

around

for another manufacturer who is willing to publish their endurance
management specs, but so far I have found nobody. I would love to hear
suggestions, if anybody knows.

=Dave

“Rob Davidson” <> rdavidson@softwareremodeling.com> > wrote in message
news:> 3C910061.5060905@softwareremodeling.com> …


Hi all,

We are using the SanDisk CompactFlash cards on our P5x little board
running QNX 4.25. We’ve noticed a large decrease in write performance
in the larger and newer SanDisk cards we’ve purchased recently (192MB,
256MB AND Ultra 256MB). Interestingly, older OEM versions of the 192MB
seem fine, but we can’t get these anymore.

I need to run some diagnostic type utilites on these disks and I would
like to use QNX instead of DOS (to prevent having to install DOS or
Win98 on these flashcards). Does anyone have any ideas on how to
perform sequential read/write tests under QNX? Anyone know if hdparm

from linux is or can be ported to QNX?

Thanks,
Rob


\