Micro SDHC Cards

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JHZR2

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I dont need a fast one, but would like a high quality one. Which ones are the best/most reliable? Are there any US made ones anymore? What brand is best?

I would like class 10 just for the future, but I think a 6 would be fine. Im not writing to it very fast.

Thanks!
 
Originally Posted By: JHZR2
Originally Posted By: EricF
Sandisk


Made in USA?


Never ever seen any kind of memory card made in USA. Other than the rocketfish flash drive. No it'll be China, Korea, or Taiwan.
 
Which is best? Korea? What mfr will most likely provide their cards from the best country?
 
I like Transcend. I have a 4GB MicroSDHC Class 6 in my phone now. I paid $15 for it this time last year. Now you can get a 8GB Class 10 for the same price. I bought mine from Newegg.com
 
There is no card made in the USA, but, Micron has a FAB in the US, and since NAND is the most expensive part of the card, they are equivalent to having the highest domestic content percentage.

Controllers are all made in Taiwan but designed in different countries depend on which company it is from. So are invisible stuff like firmware.

I'd say Micron / Crucial likely has the highest US percentage, then SanDisk (shared FAB with Toshiba in Japan), then Samsung, Toshiba, and the rest of the Taiwanese relabel brands. However they all relabel each others' stuff once in a while so you never know in the end what is in what. (i.e. I once got a Crucial / Micron card that is made in Japan and the model number said it is actually a Toshiba).

They are all tested and assembled in China, but that's a small part of the cost percentage.
 
Originally Posted By: JHZR2
Which is best? Korea? What mfr will most likely provide their cards from the best country?


Technically, Panasonic, because they OWN the standard, but they rarely made cards nowadays. So the most compatible IMO is SanDisk (because I worked there and was dealing with the battery of test to make sure they were compatible, end of shameless self promotion).

However, if you want high quality, I'd recommend skipping the bottom of the line speed class. They tend to use the 3 bit per cell memory (3LC) instead of the 2 bit per cell (MLC), so their long term reliability and durability is not as good. Most likely you won't wear it out either way, but if you want more reliability, I'd pay a bit more.
 
So isn't a class 10 (fastest) what I want then? The should have the 3-bit setup, right?

Is Sandisk though manufactured in china, fabled in Japan then? One of the two memory sticks I've had go bad on me was a Sandisk... The other was a Kingston.

Can't say I've seen any toshiba, Samsung or micron micro sdjc cards... But ice just been looking on amazon.
 
What are you writing to the card? If lots of small files (less than 4K or so), steer clear of Class 10 cards. If doing larger file sizes (MP3, JPG's, etc) then a Class 10 is great.
 
Why would that be, to steer clear of class 10 for small files? is it file system, memory address/size or something else?

4k is awful small, so Im assuming bigger than that, but much of the file writing to the card should be in the 100-1000k size.

And then Ill have a bunch in the 3-10MB size, probably a few files from my class that are 300 MB.
 
It has to do with substantial delays when the card attempts to write a tiny amount of data, then has to fill the remainder of the entire file system block.

The problem looks much the same as when the 1st gen of MLC SSD's hit the consumer market and write times too inordinately long...so long the OS was locking & hanging. Same thing here.

SanDisk class 2/class 4 cards seemingly are the on only cards on the market now to overcome this limitation and will write tiny amounts of data 50-500X faster than a class 10 card.

Initial link: http://forum.cyanogenmod.com/topic/28469-nook-color-seems-slow-running-from-sd-card/

Link embedded in that story with more details:
http://forum.xda-developers.com/showthread.php?t=1005633
 
It is not because class 2 or 4 is faster than class 10. The test spec for these classes are using large blocks of write to see how the card would handle long write for video and large photo files.

Once upon a time, many card designer optimize their speed by having the garbage collections done in the very last priority. The result is "hiccup" when you want it the worst, like video recording or large photo saving.

So the camera and camcorder producers get together for a spec to avoid these issues, by testing against large files (1MB to 4MB, for example) for worst case performance.

It is not about small files and it will never be an indicator for such. The reason of the false impression that class 2 or 4 will be faster for small file is because.... they are old cards with older memory (i.e. 56nm MLC instead of 32nm or 29nm 3LC). They were more expensive to produce but is now selling for a lower cost because they are no longer competitive, and the newer cards aren't even that big anymore.

Every generation of NAND have smaller cell size, larger block and page size, and today even more bit density per cell (3LC has 8 voltage levels instead of MLC's 4 voltage levels, or SLC's 2 voltage levle) and it takes even longer to write the same unit and they are even less durable. In flash memory you have to write one page at a time and erase one block at a time, so a lot of 4KB write will be easier to deal with in older memory with 2KB page and 512KB block than the newer memory of 4-8KB page and 2MB block.

My understanding, is that the lowest end card of SanDisk and the companies relabeling SanDisk, uses 3LC for its lower cost, then the "Ultra and low end Extreme III" uses MLC, and the Extreme IV and lightning series uses SLC. Withing this brand it would be a better indicator than speed class for small file speed, but i don't know how to compare across brand other than to avoid the lowest end cards.

Or you can dumpster dive for a small, old cards hoping for a fast one.
 
Last edited:
Panda,

thanks so much. So in laymen's terms what do I want for ultimate reliability and optimum performance for non-photo use. I dont need something optimized to write 4MB files in a fast photography setting, but I may want to read or write a big file of 300 MB without it taking forever. Besides that, it is just small files that ill swap on and off and I want reliablity.

Thanks!
 
Originally Posted By: JHZR2
Panda,

thanks so much. So in laymen's terms what do I want for ultimate reliability and optimum performance for non-photo use. I dont need something optimized to write 4MB files in a fast photography setting, but I may want to read or write a big file of 300 MB without it taking forever. Besides that, it is just small files that ill swap on and off and I want reliablity.

Thanks!


If you want it for phone use, I'd buy the fastest (i.e. Lexar Professional or SanDisk Extreme IV) cards for the size I need, rather than a lower end big capacity card.
 
Last edited:
im not using it in a phone, rather like a usb drive with swappable memory innards.
 
Panda, thank you for the explanation! Interesting to see on the chart in that link that only SanDisk cards had respectable small write performance. All others paled in comparison to the SanDisk product.

I'll check out the Extreme IV, that might just do the trick making this Nook Color feel like a usable product again. Thanks!!
 
Originally Posted By: ToyotaNSaturn
Panda, thank you for the explanation! Interesting to see on the chart in that link that only SanDisk cards had respectable small write performance. All others paled in comparison to the SanDisk product.

I'll check out the Extreme IV, that might just do the trick making this Nook Color feel like a usable product again. Thanks!!


I just checked, there isn't Extreme for MicroSD, Ultra is apparently the highest they get. Which make sense since SD is a very slow interface.

A lot of the speed comes from running the memory chip in interleave (parallel) at the same time and MicroSD is so small that you can't put too many chips together. Maybe that's why everyone is slow.

Originally Posted By: JHZR2
im not using it in a phone, rather like a usb drive with swappable memory innards.


I'd use a faster interface memory like USB stick than a USB adapter with MicroSD. The bottleneck would still be in the SD interface and since you have much more room with USB, you can just use a native USB interface stick.
 
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