Is Flash memory inherently unreliable?

[KeiCar]

Im noticing a unsettling trend with some of my tech gear, mostly with my micro SD cards but some of the regular sized cards as well. What happens is the card will be working fine (sitting idle or actually being read / written to) and then I'll notice (if its an android phone) an icon stating that the external memory has been abruptly removed. This isn't so much phone model specific as I have had a lot of phones over the years and the behavior is the same among all of them (all versions report on external memory behavior in a similar fashion).

The other issues are with devices that aren't always turned on, such as my cameras. I have a Nikon D3100 DSLR, Canon Vixia HFS100 and now just recently an (Excellent BTW) Sony HDR-CX160, these all have had issues during startup of "No external memory found" or "External memory database damaged, repair or quit", something similar. In the devices that also have internal memory (I know the Sony has 16GB built in) I NEVER get an issue with the internal, just external.

Now most of the memory (some 95% of it) is Sandisk or another high end brand, not specifically 1st tier (Branded Sony, Canon..ect memory), not that it matters since I think between such brands all the dies are off the same assembly line. I never use no-name or fake branded memory for obvious reasons. I also use Micro SD specifically because:
-They have class 10 speeds, so its just as fast as the full size and thats fast enough for me
-They can be swapped between devices (Phone--> DSLR--> Video Cam--> Laptop--> Friends "device" --> PSP (via Memory_Stick -> SD adapters)...ect. You see where Im going.

Now I've gotten a bunch of adapters laying around so if ever I have issues I can always try to eliminate 1 of the possible "weak links" by immediately replacing the adapter, this works around 2% of the time. I have no issues with using the adapters since, electronically speaking" their so stupid simple devices all it does is really lengthen the pins a bit so they reach their intended mount points in said device.

EDIT: I just remembered I use a standard SD card in my DSLR now, its still just a class 10 PNY 32GB (20MB/s) "Professional" branded card. I think I just got a great deal on it so I purchased it...

[Egilbe]

I've never had any problem with flash memory. I'm using the same 16 gbs stick for the last 5 years in three different phones, but I don't spend a lot of time removing and inserting it, either.

If you are removing/replacing it, you create more risk of the ram being destroying by electrostatic discharge. Most jolt's that destroy IC's are so small that you can't feel it.

[spoonie]

no problem with usb flash keys (some pretty old) or sd cards generally.

however, the 2gb flash cards that my stereo is limited to - i'm getting occasional errors and skips on my mp3 files that are otherwise OK on my computers.

[GeoffD]

ESD and bad connectors are the most common points of failure. FLASH soldered to a printed circuit board is bomb-proof.

FLASH does have a limit on the number of writes you can do per memory cell. The device driver has an algorithm to try to uniformly distribute the writes across the device but those don't work well if the device is almost full or if you're doing something that is doing constant write-read-delete cycles to the media (page faults by the operating system when the memory pool is exhausted, for example).

With my cameras, I tend to just buy more FLASH cards as I fill them.

[theevilshiftkey]

Out of all the cameras, phones, PDAs, tablets, PCs, MP3 players and USB sticks I've owned I've never had one fail. In fact I still have the very first USB stick I ever owned, a big 64MB of power and it still works too.

Maybe you should stop shuffeling around the shag carpet every day.

[dr_spock]

How are you formatting your SD cards before use in the devices?

[KeiCar]

How are you formatting your SD cards before use in the devices?

Let me check. I usually format the card within the device itself so I know compatibility is guaranteed. My macbook has a NTFS plugin so I can read/write
ntfs within the OS, so if android works best with that particular file system, Ill use that. I really don't know which FS to use that Android prefers and is reliable with large capacity
cards. I think Ive used Fat32 in the past for maximum compatibility despite the fact that its an old FS that isn't that reliable...

[Egilbe]

Let me check. I usually format the card within the device itself so I know compatibility is guaranteed. My macbook has a NTFS plugin so I can read/write
ntfs within the OS, so if android works best with that particular file system, Ill use that. I really don't know which FS to use that Android prefers and is reliable with large capacity
cards. I think Ive used Fat32 in the past for maximum compatibility despite the fact that its an old FS that isn't that reliable...

Android likes EXT4

[PhReE]

Android likes EXT4

Do all versions of Android support EXT4? Or what is the minimum version?

[Egilbe]

Do all versions of Android support EXT4? Or what is the minimum version?

for the last two years, anyway. Android is a lite version of Linux. Everything important is basically the same. Same commands, same way to install programs using a shell as Unix or Linux. It's jsut a very lite version for cell phones.

http://arstechnica.com/information-t...ear-data-loss/

[PhReE]

for the last two years, anyway. Android is a lite version of Linux. Everything important is basically the same. Same commands, same way to install programs using a shell as Unix or Linux. It's jsut a very lite version for cell phones.

http://arstechnica.com/information-t...ear-data-loss/

Yeah, lol, I know it's Linux, but it uses a fairly old kernel and I wasnt sure if that kernel had EXT4 support or not.

[Egilbe]

Yeah, lol, I know it's Linux, but it uses a fairly old kernel and I wasnt sure if that kernel had EXT4 support or not.

It has since 2.1 or 2.2, somewhere around then.

[O_loung1]

i have the same dlsr as the op and i always have problems with my micro sd + adapter cards till
the point i dont even use them. the brands i have used are mainly kingston and sandisk micro sds
but they both seem fairly unreliable.

with traditional sd cards from class 4 to class 10, i never have had a read error from any brand
on multiple devices, whether it be kingston, sandisk, pny, polaroid or amazon.

[zhenya00]

You guys who are having problems, have you bought your cards from the same retailer? I know that counterfeit memory is a big deal and fairly common on Amazon, and even places like Newegg sometimes end up with shipments of it. It looks like the real deal, but dies very quickly. That's the only kind I've ever had fail. I have tons of cheap (but not counterfeit) flash drives that have been in use for 5 years or more.

[KeiCar]

Recently mine have all be purchased in stores. I did run into an issue with fake memory before that I knew was too good to be true (to cheap), well guess what... It was too good and died on me.

What I read that they did was alter the file partition table somehow to show a larger amount. I don't think that is hard to do. Unfortunately you end up getting errors on the card and the first time you try and format it, it hoses the card.