On Sat, 20 Mar 2021 16:04:32 +0000, Jim Jackson wrote:

> On 2021-03-19, Craig Dooley
>  wrote:
>> BY: mm0fmf(3:770/3)
>>
>>
>> m> I've used Pi's since as soon as I could buy them but I've never run
>> one m> 24/7 before so I'd like to ensure I've done sufficient to
>> maximise SD m> Card life.
>> m>
>> Not sure what Pi you have, but if it's a 4, have you thought about
>> going with USB instead of SD card?  I've currently got my BBS running
>> on a RPi 4 with everything on a USB drive.  128 GB flash drive the size
>> of my thumbnail plugged into one of the USB 3.0 ports.  Works fine, and
>> I don't have to worry about read/write cycles.
>
> It's flash whether the interface is SD or USB - there is a write limit!

IIRC the on-device controller on any type of SSD is a lot smarter than
the ones fitted to a built-down-to-price semi-disposable SD card, and one
place this shows up is in dealing with card wear, i.e EEPROM ageing
defects. I don't think any SD card can remove a bad memory page from the
active pages map and replace it with one of the spares - something most
SSDs can do - because for starters SD memory pages are relatively large
(4Kb?) and pricing says they don't have any list of spare pages or a
controller that could handle remapping.

I'm told that the better (enterprise grade) SSDs will drop into read-only
mode when they find a prefefined unfixable number of defects. This means
the data content can be retrieved without errors. Lower spec SSDs and all
SD cards will merrily go on writing data well past that point.

--
Martin    | martin at
Gregorie  | gregorie dot org

--- SoupGate-Win32 v1.05