Joel Cochran wrote:
John,
What do you mean by "general processing"? The database is on the CF card,
the application accesses the database. Other than what application
normally
do (select, update, insert, etc.), I'm not sure what else to tell you.
Or do you mean over the course of the lifetime of a CF card it can only be
used so much? That might apply to this scenario, these cards have been
written over continuously for the last 6 months.
From Wikipedia:
Note: flash memory supports only a limited number of erase/write cycles
(around 1,000,000 write cycles for NAND flash memory) before a
particular "sector" can no longer be written. Typically the controller
in a CompactFlash attempts to prevent premature wearout of a sector by
mapping the writes to various other sectors in the card - a process
referred to as wear levelling.
My understanding is that "industrial" flash supports a lot more
erase/write cycles than "regular" flash, but its also a lot more
expensive. I'd check your CF card documentation to see what your
average write cycles per sector is. If you are constantly writing to
the database, you are likely to kill sectors a lot faster. Out of
curiosity, just how often *does* the database get written to?
Typically you write to flash only when you have to, and try to keep
things in memory as long as possible/feasible. That being said, I'm
sure there are embedded device experts on this list that can provide
better tips on how to extend the expected life of your flash card.
Joel
On 4/13/07, John Stanton <[EMAIL PROTECTED]> wrote:
Regular flash memory has a limited number of write cycles before it
fails. Are you hitting this problem by using it for general processing?
--
Glenn McAllister <[EMAIL PROTECTED]> +1 416 348 1594
SOMA Networks, Inc. http://www.somanetworks.com/ +1 416 977 1414
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