Question conserve SSD - Page 1
Forum section: electronics / general

author: classicsamus87
author_rank: Regular Contributor
timestamp: October 01, 2020, 03:09:51 pm
content: I have a KingDian SSD stored, how to store it correctly and protect its electronics?

author: Twoflower
author_rank: Frequent Contributor
timestamp: October 01, 2020, 03:42:56 pm
content: SSDs are not useful devices for archive data. They need to be powered on every now and then to restore the data. The dataretention time highly depends on many factors (how many bits per cell, temperature, how often the cells has been written...). Under bad conditions that can go down to months or less. Especially for heavily used devices.The manufacturer of your SSDs doesn't state the Data Retention Time for their products. So either you should ask them to provide that data or use other devices that provide that data.Beside that, or you only want to store that SSD. The data sheet states the storage temperatures and humidity. Usually lower temperatures that doesn't change would be best but you should stay within the storage conditions. Use an ESD-Bag to prevent ESD damage.

author: classicsamus87
author_rank: Regular Contributor
timestamp: October 01, 2020, 04:23:18 pm
content: In this case, I would save it for future use and not to store data, the SSD is new in the packaging.on flash memories if I record once and save for a long time (USB Flash Drive, microSD card and SSD) is it impossible to avoid data loss?

author: electrolust
author_rank: Unknown
timestamp: October 01, 2020, 05:45:57 pm
content: yes. there is almost no consumer media that will not lose the data over time. The longest lasting technology is the M-Disc, which is 1000 years for the DVD version. (There's a blu ray version as well but it doesn't last longer than normal blu ray, which isn't very long. The advertising on the M-Disc blu ray is highly deceptive in this regard.) It's write-once, not rewritable, so it may or may not meet your requirements. You need an M-Disc-specific writer, but any DVD-ROM drive can read back the disc.Once written, a flash drive is estimated to last about 10 years. To be safe, I'd replace it every 5 years. This is highly dependent on storage conditions, though. Annually might be safer depending on that.No matter the technology, you want multiple copies, stored at multiple locations. So if you had 2 drives with the same data, alternate the replacement every 5 years and you should be good.If you are ok with the smaller data size of DVD, and the write-once nature, I would trust M-Disc for archival storage.

author: Twoflower
author_rank: Frequent Contributor
timestamp: October 01, 2020, 06:21:28 pm
content: The technology behind FLASH is to tunnel electrons through an insulator (pushing them hard enough that this happens). This process damages the insulator. Since there is a way in, there is also the chance that these electrons can escape by pure chance (yes, welcome to the quantum world). This insulator wears down by each erase/write cycle that the chance that these electrons can escape gets bigger each time. And with todays technology we're speaking of100s of electrons(Chapter 1, paragraph 3. And that paper is from 2015) storing your precious data.**The same problem appears for any memory using trapped electrons (FLASH). Some are more problematic (multi-level flash cells, storing more than one bit per cell) some not (single level cells). In the end it comes down to memory density (simplified). But sooner or later the data is gone.I have no experience how good or bad other FLASH based memories behave. But they are based on the same technology. The only difference is that usually a memory sticks or memory cards are not written that often (except if used in computers like the RasPi). Every erase/write cycle damages the cells and increases that the trapped electrons can escape easier. So an only one time written memory card might hold the data for reasonably long time. But in the end I would trust a branded SSD more as they can squeeze more and better compute power into the controller that drives the memory chips to check and correct data.Also the quality of the used memory chips itself has a huge impact. Cheap drives (SSD, USB or memory cards) often come with cheap chips not meet the high end performance used for the more pricier and more reliable devices.For backup the media of choice is still magnetic media (HDD or tape) or writable discs if copied regulary. Except maybe some more exotic stuff likeglass mediaor even DNA.** It is totally amazing that you have a device that can detect the charge of few 100s of electrons for nearly no money at all!

author: classicsamus87
author_rank: Regular Contributor
timestamp: October 01, 2020, 07:42:35 pm
content: i will not write frequently in flash memory (microsd, usb flash drive and ssd) i will write only once and store, will the data be lost after 5 years of storage?

author: Twoflower
author_rank: Frequent Contributor
timestamp: October 01, 2020, 08:22:01 pm
content: You have to ask the manufacturer about the retention time for that very specific device. Here no one can give you the answer. Use a genuine brand memory device that provides that information and you might be able to use it to store data for that provided amount of time. But you'll have a hard time to get such data. Even SanDisk (WesternDigital) or Samsung don't put any information about that in the public data sheets. There are only some generic information available but not device specific (Code:https://www.jedec.org/sites/default/files/Alvin_Cox [Compatibility Mode]_0.pdf, Sorry, since the URL contain brackets I can't make it clickable, page 26). I personally would not use a FLASH based media as single backup.You probably only get answers here from older (most likely more robust) devices that ain't comparable with todays devices. No one has 5 years experience with SD cards you can buy today.

author: BravoV
author_rank: Super Contributor
timestamp: October 02, 2020, 05:10:55 pm
content: Quote from: classicsamus87 on October 01, 2020, 07:42:35 pmIf I say YES , it will be lost, would you accept it ?orIf I say NO, your data will not lost after 5 years, do you believe me ? Or this is what youwant to believe.And NO, flash memory is not designed and made for long term storage, even you write it only once.

author: wraper
author_rank: Unknown
timestamp: October 02, 2020, 05:21:09 pm
content: If you want somewhat long storage time in unpowered state, you would need SLC NAND based SSD. Otherwise I would not count on unpowered drive storing data for more than a year. As of SD cards and sorts of, they unlikely to refresh any data even in powered state so eventually will lose the data regardless.

author: BravoV
author_rank: Super Contributor
timestamp: October 02, 2020, 05:36:26 pm
content: Quote from: wraper on October 02, 2020, 05:21:09 pmThe op is using low end cheap ssd, prolly filed with low quality or rejected flash chips.

author: classicsamus87
author_rank: Regular Contributor
timestamp: October 03, 2020, 11:38:08 am
content: I have some cartridges that I store and in them the OS is saved in some internal flash memory is the Super Everdrive China Version but if I knew that the OS is automatically deleted stored I would not have acquired a backup unit

author: wraper
author_rank: Unknown
timestamp: October 03, 2020, 12:06:16 pm
content: Quote from: classicsamus87 on October 03, 2020, 11:38:08 amThat's a NOR flash made on thick node with at least 20 years of data retention guaranteed. Don't confuse it with modern NAND.

author: classicsamus87
author_rank: Regular Contributor
timestamp: October 03, 2020, 03:05:30 pm
content: thanks for the answer, I didn't know about NOR flash technology but does it also have a data retention limit? after 20 years of storage, is the data automatically deleted?

author: wraper
author_rank: Unknown
timestamp: October 03, 2020, 04:23:59 pm
content: It's not automatically deleted. But memory cells slowly discharge. How fast depends on technology IC was made with, temperature, erase/write cycles and even quality of particular IC (there are process variations). 20 years is minimum guaranteed. It might last 100 years easily.

author: classicsamus87
author_rank: Regular Contributor
timestamp: October 03, 2020, 04:33:12 pm
content: Isn't this slow discharge avoided if the device with the memory is used once a year or once a month?Nor Flash are all flash memories that are soldered on the PCB? microsd card, usb flash drive and SSD do not use Nor Flash do they use Nand flash which has a data retention in less time?Does SSD have moisture corrosion problems?

author: wraper
author_rank: Unknown
timestamp: October 03, 2020, 04:37:27 pm
content: Nothing is avoided by simply powering Flash memory IC. SSD rewrite the old data from time to time to avoid data corruption.QuoteNOR flash is different memory technology with much lower size. It's not allowed to have bad blocks unlike NAND. NOR is usually used to store things like firmware, motherboard bios and sorts of without any bad block management. Either of them is soldered on the PCB.

author: classicsamus87
author_rank: Regular Contributor
timestamp: October 03, 2020, 08:09:59 pm
content: In the photos of the card I posted where is the NOR flash chip? can these chips reach 100 years of retention?

author: wraper
author_rank: Unknown
timestamp: October 03, 2020, 08:14:30 pm
content: Quote from: classicsamus87 on October 03, 2020, 08:09:59 pmI even attached datasheet. 20 years is the guaranteed figure. Nobody knows for sure if it will last 100 years. This data is acquired by accelerated tests. Chip may simply fail in such a long time besides problems than retention. Also in 100 years there likely will be no off the shelf equipment to read this data.

author: Halcyon
author_rank: Unknown
timestamp: October 06, 2020, 05:27:08 am
content: Quote from: classicsamus87 on October 01, 2020, 03:09:51 pmIf it's a cheap Chinese SSD, I probably wouldn't be too worried about how you store it. It'll probably fail when you go to use it anyway.