Old sd card dodgy performance? ssd speed loss on old data?

Cyber-Mav · 9 Nov 2023 at 22:31

so pulled out my camera which has not been used for probably a year. took the sd card out of it and it had few gigs of photos on it. thought ok its a samsung 32gb card, put it under hdtune for a read test and was surprised to see its read speed to be around 4 megabytes per second on the areas where the data was. empty areas were around 40megs a sec speed.
done full format of the card and benched it again this time it flatlined from start to end at 44megs a sec.

now i know samsung had ssd issues that suffered performance loss after a few months on old data and firmware fixes tried to rewrite the data in he flash cells but still wasnt fully fixed. but looks like this issue affects sd cards and probably other flash media too.
looks like using flash for long term backup storage is not a good idea.

i didnt do any other tests on it though, i should have left it plugged in to the pc for a few hours and then done a read test again to see if the card had done any sort of refreshing itself?

anyone else notice this on flash media?

Cyber-Mav · 9 Nov 2023 at 22:44

just saw this same phenomenon on wifes old 200 gig sandisk micro sd card. its been in storage for only few months since i got a 512gig card and passed here my 256gb card so the 200gig card just sat around. performance is very slow but when wiped and fresh data put on it the card works at full speed.

Snapshot · 10 Nov 2023 at 07:06

Cyber-Mav said:
looks like using flash for long term backup storage is not a good idea.

This is well known. Flash memory needs periodic refresh to avoid data loss which makes it unsuitable for long-term storage.

Cyber-Mav · 10 Nov 2023 at 07:11

how does it refresh? does it do it on its own or do you need to manually copy data off it and back onto it?

Cyber-Mav · 10 Nov 2023 at 08:18

ok doing more testing on this now.
here is a scan of the 1tb kioxia m.2 nvme drive i use for games, its got 42gig free space left on it. only cyberpunk is played from it and beamng.drive, so rest of the data been sitting on it for many months. this is on a gen2 mobo slot

you can see from first run there is a lot of dips in speed.

i then ran a full error scan on the drive using hdtune and then benched it after here is the result:

looks like doing that scan clawed back a lot of the performance. will run a few more scans on it and see if there is a difference.
odd that doing a read on the drive this way made such an impact to it?

Cyber-Mav · 10 Nov 2023 at 08:32

and here is the result after the 3rd surface scan:

i gonna check if i got some old usb sticks lying around and do some benches on them if they got old data on it.