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

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.

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

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.

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