experience with max block erase

Vipin Malik vipin.malik at daniel.com
Thu Jan 17 16:41:55 EST 2002

Herman Oosthuysen wrote:

> 100 000 cycles is lot.  You have to erase the chip about ten times per hour
> continuously for 100 years to reach that number...

Let's state 100K cycles another way:

for a 8mbit chip (1024KB)

It's only 100K * 1024KB of data life (assuming a circular use- which is the
best case and what you will get with wear leveling).

If you want your product to last 8 years (pick a number), then the max data
rate that you can send to the flash chip is "only":
100000 * 1024/(8*365*24*60*60) = 0.4KB/sec!

That's not a lot. This does not even take into account the extra data generated
due to the overhead of any filesystem one may be using. Tack in another 20% for
that (not unusual for JFFS2 system- it depends on write sizes- this assumes a
small write size/write) then the data rate falls to 0.32KB/sec

OR let's say that the system is generating data (that needs to be saved to
flash) at the rate of 10KB/sec (not very high number too), then the life of the
system is only 0.32years! (Yikes!)


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