With all the talk about flash...

[alank2]

One thing I noticed in the other thread was this 3 month figure given when it is AT the rated P/E cycles.  What about if it is new or not at the end of its life.  If you took a new piece of flash and programmed it, how long would it be reliably readable?  1 year?  2 years?  5 years?  10? 20? etc.

Some of the i2c EEPROM I've been using says 200 years...

[ataradov]

If you took a new piece of flash and programmed it, how long would it be reliably readable?

Most flash ICs specify 20 years of data retention.

[bktemp]

It depends on the type of flash: I2C EEPROMs use NOR flash and are designed for a high number of write cycles with no biterrors, while SSD uses multi level NAND flash, designed for maximum density. NAND flash has a high number of bit errors, therefore requires a strong error correction.
The data retention of NOR flash is much higher than for NAND flash because of the much larger cell size.

[ion]

It seems to be related to the process size.
After coming across that thread I decided to read up on it and it seems that high density flash chips using the smaller feature sizes currently available tend to be rated for 1 year at room temperature at worst ( at least from the datasheets I found in the short time I spent searching).  High temperatures seem to have a significant effect on that though.

Lower density stuff with correspondingly larger feature sizes are more like 20 years, and I think I saw something about some types of SLC chips having a data retention of up to 100 years.

[Fungus]

If you took a new piece of flash and programmed it, how long would it be reliably readable?  1 year?  2 years?  5 years?  10? 20? etc.

It depends on the type of flash, the density, the gate sizes, etc. Some will last a few months, some will last for decades. See the datasheet.

Storage temperature is a big factor.

[georges80]

Yeah, refer to the datasheet.

One small 8mbit device I'm using claims 200 years retention and 4 million write cycles. Obviously NOR technology (eeprom).

cheers,
george.

[Fungus]

The datasheet for AVR chips (Arduino) says:

"Data retention: 20 years at 85°C/100 years at 25°C"

I don't have any other datasheets at hand.