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SSD question
newbie questions he
Do internal SSD cards require a constant uninterrrupted supply of power to maintain the data stored in it? What about external SSD cards? I just saw an ad for a portable SSD (Crucial 500GB X8 Portable SSD - Up to 1050 MB/s - USB 3.2 - USB-C, USB-A - CT500X8SSD9) that jogged my questions. If they do, how long can they go without power before the data is lost? Thanks, John |
#2
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SSD question
On Sat, 9 May 2020 18:03:53 -0000 (UTC), "Yes"
wrote: If they do, how long can they go without power before the data is lost? No manufacturer will include a piece of paper with fine print that says - 'don't store important data on our drive that isn't powered from a computer, because it will all fall out, due to rot, at precisely 42,389,467 hours.' Bit rot is theoretical. Like trade-show laptops equipped with inexpensive SSDs units that, with a nudge and wink, get reviewed for a life expectancy of a year. |
#3
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SSD question
Yes wrote:
newbie questions he Do internal SSD cards require a constant uninterrrupted supply of power to maintain the data stored in it? What about external SSD cards? I just saw an ad for a portable SSD (Crucial 500GB X8 Portable SSD - Up to 1050 MB/s - USB 3.2 - USB-C, USB-A - CT500X8SSD9) that jogged my questions. If they do, how long can they go without power before the data is lost? Thanks, John https://blog.macsales.com/43702-we-b...-exercise-too/ ideal storage environment, usually mentioned as around 25 C hard drives are predicted to be able to retain their data for 9 to 20 years Now, say an SSD is rated at 3000 writes per cell, and you've just completed write 3000 of all cells. The reliability under this ridiculous assumption is: Consumer grade SSD: 1 year at a 30 C storage temperature. Enterprise grade SSD: 3 months at 40 C storage temperature. Because the cells are worn out, there is already some threshold shift there, and the quoted retention is with that threshold shift in place. ******* So they've upped the temperature a bit to enhance leakage, and quoted a number. This doesn't tell us how a drive with 100 writes behaves, when you leave it in a cupboard. SLC (single bit per cell) technologies and the floating gates they use, those last for around 10 years. The invention of higher density MLC, TLC, QLC has degraded that number. The number will be higher than the "3 months" or "1 week" quoted in the article, but it also won't be ten years, but some lesser number of years. BluRay MDisc - lasts as long as polycarbonate lasts Hard drive - good, as long as the storage is cool and *dry* flash based - not as good as the other two - not suited for time capsule burial in the back yard. forty years from now it will be erased. Paul |
#4
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SSD question
BluRay MDisc - lasts as long as polycarbonate lasts Hard drive - good, as long as the storage is cool and *dry* flash based - not as good as the other two - not suited for time capsule burial in the back yard. forty years from now it will be erased. Paul DLT and 3590 tape were claimed to have a life of 50 years (if stored properly). I've had no trouble reading 20 year-old tapes. The older stuff (9-track) gets to be a problem. |
#5
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SSD question
Paul wrote:
Yes wrote: newbie questions he Do internal SSD cards require a constant uninterrrupted supply of power to maintain the data stored in it? What about external SSD cards? I just saw an ad for a portable SSD (Crucial 500GB X8 Portable SSD - Up to 1050 MB/s - USB 3.2 - USB-C, USB-A - CT500X8SSD9) that jogged my questions. If they do, how long can they go without power before the data is lost? Thanks, John https://blog.macsales.com/43702-we-b...-exercise-too/ ideal storage environment, usually mentioned as around 25 C hard drives are predicted to be able to retain their data for 9 to 20 years Now, say an SSD is rated at 3000 writes per cell, and you've just completed write 3000 of all cells. The reliability under this ridiculous assumption is: Consumer grade SSD: 1 year at a 30 C storage temperature. Enterprise grade SSD: 3 months at 40 C storage temperature. Because the cells are worn out, there is already some threshold shift there, and the quoted retention is with that threshold shift in place. ******* So they've upped the temperature a bit to enhance leakage, and quoted a number. This doesn't tell us how a drive with 100 writes behaves, when you leave it in a cupboard. SLC (single bit per cell) technologies and the floating gates they use, those last for around 10 years. The invention of higher density MLC, TLC, QLC has degraded that number. The number will be higher than the "3 months" or "1 week" quoted in the article, but it also won't be ten years, but some lesser number of years. BluRay MDisc - lasts as long as polycarbonate lasts Hard drive - good, as long as the storage is cool and dry flash based - not as good as the other two - not suited for time capsule burial in the back yard. forty years from now it will be erased. Paul Thanks. Interesting article. Seems to answer my question; I'm used to temperatures expressed in Farenheit but I've bookmarked sites that provide conversions. John |
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