iPod flash memory lifetime concern

[mahen]

Hi everyone,

a very simple question just came to my mind. We all know that flash memory has a limited count of "writes" (a few thousands ?), and also that Rockbox completely shuts down the iPod instead of switching it to a "light sleep mode".

This means that some pieces of information such as the name of the last file played was written to the flash memory. so... If you turn on and off your ipod a couple of times a day... Is it likely to die within... ONE year ?!

cheers !

- mahen

[bonham]

As said in this Wikipedia article : http://en.wikipedia.org/wiki/Flash_memory.

A flash memory, depending on its type, may endure from about 10,000 to about 10,000,000 write cycles.

(sorry for my poor english, I'm french)

[Dwyloc]

a very simple question just came to my mind. We all know that flash memory has a limited count of "writes" (a few thousands ?), and also that Rockbox completely shuts down the iPod instead of switching it to a "light sleep mode".

Another good question is why dose rockbox not put the ipod into a "light sleep mode" as well like the stock firmware?

If apples web site is to be believed putting your ipod into “deep sleep mode” then booting again after just a few minuets or an hours or two uses more power than using the “light sleep mode” so by shutting down and booting quite a lot the way rockbox works at the moment may reduce battery life as well as shorting the life span of flash based player like the ipod nano.

[Llorean]

1) Assume that the iPod flash has 1,000,000 writes. (It should have at least this much.) There are 365 days in a year. For simplicity of math we'll round up to 400. If you shut down once a day, you write once a day. At 400 days a year (more than a normal year) you get: 2500 years. Now, assume you do it twice a day. 1250 years. 20 times a day? 125 years. Do you think your iPod will last this long?

2) Rockbox just doesn't *have* a sleep mode yet. The reason it doesn't put it into a light sleep mode is an entire lack of one being written yet.

[Xoder]

1) Assume that the iPod flash has 1,000,000 writes. (It should have at least this much.) There are 365 days in a year. For simplicity of math we'll round up to 400. If you shut down once a day, you write once a day. At 400 days a year (more than a normal year) you get: 2500 years. Now, assume you do it twice a day. 1250 years. 20 times a day? 125 years. Do you think your iPod will last this long?

In addition, Llorean's math assumes that you keep writing to the same exact cells on disk. Most flash drives have low level firmware that ensures that writes are distributed evenly among the cells to provide better wear.

[Llorean]

Yeah, it's true, mine is a worst-case scenario.

[Dwyloc]

2) Rockbox just doesn't *have* a sleep mode yet. The reason it doesn't put it into a light sleep mode is an entire lack of one being written yet.

Thanks that answers the part of the question I was most interested in as I expect the battery will fail before the flash chips and as the battery is soldered to the board it is most likely the part that will end the life of the ipod nano first.