[CALUG] Can Media cards have bad blocks?

[Bryan J Smith]

All commodity NAND blocks have bad cells from virtually day 1.
Within 1,000 writes, they will be unreliable.  These are the reality
of the technology today.  They are also normally very slow at
writes, but techniques are used to sychronize commits in the
circuits.
Access times are much better than disk, but still poor next
to actual DRAM (let alone SRAM).  NAND != RAM, no matter how
much people assume otherwise.

--  
Bryan J Smith - mailto:b.j.smith at ieee.org  
http://www.linkedin.com/in/bjsmith
Sent via BlackBerry from T-Mobile  
    

-----Original Message-----
From: James Ewing Cottrell 3rd <JECottrell3 at Comcast.NET>
Date: Fri, 09 Apr 2010 18:42:04 
To: Rajiv Gunja<opn.src.rocks at gmail.com>
Cc: CALUG<calug at unknownlamer.org>
Subject: Re: [CALUG] Can Media cards have bad blocks?

If you asked me 8 days ago I would have said...

No. Flash drive always record all data accurately.

But the other 364 days a years....

If a device can have Good Blocks, it can have Bad Blocks.

JIM

Rajiv Gunja wrote:
> Hello,
> I have been using my Mobile to listen to Music and Audio books rather 
> than carry around both my Mobile and iPod. The other advantage being, I 
> have a stereo bluetooth headset for my Mobile.
> 
> On the media card 8GB MicroSD, There are folders created by my 
> BlackBerry. I have created couple of folders on them too, within the 
> directories it has created.
> 
> Under Documents, I have created Audiobooks and eBooks. For some reason, 
> if I copy my MP3s to "Music" folder created by the BB OS, BB hangs and 
> becomes very slow and I have remove the SD card to make it respond. 
> Whereas if I copy those same MP3 files to "Audiobook" directory, it 
> works fine and plays fine too.
> 
> Is this because there are bad block or whatever is holding the 
> information? Is it time to buy another card?
> 
> -GGR
> 
> 
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