Originally Posted by keithlakey
It appears (with an annoying 60% certainty) that MicroSD and MicroSDHC sizes overlap.
If MicroSD is using Fat32 and MicroSDHC is not using Fat32(??), this is significant.
So, it appears, both SD and SDHC comes in 4G, but different file systems.
This reference implies the above: SD Card: Information and Much More from Answers.com
....but doesn't state it outright. (I believe this is a copy off of Wikipedia)
This source supports the above statement, unless Samsung's PR
people were sloppy with distinguishing between the two formats: SAMSUNG Develops Mobile Phone Memory Card with Record Storage Capacity SAMSUNG
To add to the confusion, some BB-83xx's appear to report the capacity
correctly, even though they are not be able to use the full reported
blackberryFAQ.com just adds more confusion, stating a compatibility difference between 83xx models. [url=http://blackberryfaq.com/index.php/What_type_and_size_Media_Card_can_I_use_in_the_810 0_/_8300_/_8800%3F[/url]
The FAT32 thing isn't clarified either. Versions of fat32 have capacities ranging from 32GB to 8TB, (depending on the implementation), so fat32 all by itself is not a limiting factor.
Another reference says the incompatibility lies with memory addressing:
(sector addressing vs byte addressing) [url=http://en.wikipedia.org/wiki/Secure_Digital_card#SDHC[/url]
There's no shortage of opinion (guessing) on this though.....
Is there a way to get someone with some real authority on this to comment ?
Rule number one: never trust sites like answers.com or wikipedia.org!
The best place to find these types of answers are from the standards groups who define exactly what manufacturers must adhere to for the designation, or the manufacturer websites.
I posted on this subject in a different thread posting detailed information supplied by Sandisk
There is no overlap- above 2Gb, all cards are microSDHC. Filesystem on microSD is FAT 16, whereas microSDHC are SD FAT 32.
The microSDHC standard is NOT backwards-compatible with microSD because of this filesystem difference.
Hence reader (be it your BlackBerry, card reader or otherwise) MUST be microSDHC certified.
I'm assuming all of the RIM devices that support the media card are compatible, but don't quote me on that one. I just checked for my Curve since that's all I cared about!
Just be forewarned if you want to use a separate reader for the MicroSDHC, it must be SDHC-compatible. Lots of computer and stand-alone card readers that are over two years old probably are NOT.