[Discuss] SD Cards, cheap and here for a while?

[richard.pieri at gmail.com (Rich Pieri)]

On 8/24/2016 8:12 AM, Robert Krawitz wrote:
> I've also found SD cards to be unreliable (sometimes but not always
> DOA) compared to SSD.  I bought a new micro SD for my phone; I tested
> it prior to entering it into service, and it locked up hard after
> about 4 GB of testing, after which it went permanently catatonic.  The
> card it replaced developed silent write errors after about 2 years.

I've had USB flash drives show up DOA, too. Electronics fail. It
happens. That said, none of my Samsung and SanDisk SD and micro SD cards
have failed on me. I can't speak to cheaper brands like PNY; I tend to
avoid them because of poor performance.

But a thing to remember: any of our experiences, good or bad, are
statistically insignificant. These cards -- or more accurately the flash
chips in them -- are manufactured in quantities measured in tens, maybe
hundreds, of millions.


> And I had had another such that was *ahem* mismarked.

Fakes are a thing, especially in the higher capacities.


On 8/23/2016 11:41 PM, Eric Chadbourne wrote:
> Fascinating stuff.  Was just reading about the "protected area".
> Didn't know about that.  https://en.wikipedia.org/wiki/Secure_Digital

That protected area is what differentiates SD (Secure Digital) from MMC
(Multi-Media Card). I don't know any manufacturer that's actually used
that protected area; it's really just there as a sop to Big Content like
the blank tape tax.

-- 
Rich P.