Hi,

Sandisk recently announced the release of a microSDXC card [1] and I'd like to know if the N900 cardreader is able to use such a card. I've read that it should be available from October this year.
I know the hardware specification is slightly different from SDHC and SDXC uses the crappy ExFat file system but I've heard rumors that some SDHC readers are already SDXC-capable even if not specified so. And I hope the same goes for some microSDHC readers, including the one in the N900. The file system could be changed anyway.

Frankly the Sandisk card doesn't look that appealing to me (64GB@30MB/s for $200+) but I think later cards might be useful. I'm not really interested in the capacity but if one day cards would be available that actually reach the ~100MB/s which the standard provides swapping could become unnoticeable and the precious internal storage of the N900 could be saved from unnecessary write accesses while still increasing speed.

So if somebody should be able to get hold of this or any other microSDXC card it would be very nice as a proof of concept to format it to ext2 and just check if the N900 can mount it, read and write data. And of course it would be nice to share the results here.

Thanks!

[1] http://www.sandisk.com/products/mobi...microsdxc-card

Unless a Micro SDHC card is actually produced we can't know for sure.

However, considering how expensive such cards are likely to be at launch, I would be hesitant to fork out the money and stick one into a device that doesn't advertise compatibility less I risk damaging the card's contents with too low a write speed or having it just plain not work at all.

People have asked here about compatibility for SDXC many times before. Theoretically it will work, but you'll need to reformat it with a supported filesystem, the Linux kernel driver for the card reader has supported the SDXC spec for ages so it shouldn't be a problem. There are also open source implemenations of ExFAT which might be able to be ported to the N900 should anyone care enough to.

I'm sure as soon as someone with a N900 gets a SDXC card they'll post back results here.

This is why I'm asking now. Apparently at least one is actually being produced right now.

The same goes for me. But if I had an otherwise good use for such a card, maybe my very new professional camera would support SDXC, I'd give the card a try in the N900 before using it the first time in the camera.

You'd have to reformat the card anyway to use it in the N900. So data loss is no issue because you know in advance that all data on the card will be lost.


But this is the first time it's not only a theoretical topic. With any luck we could know the answer within a month.

I'm aware that on the software side there shouldn't be any problem. Thanks anyway! My question is if the hardware, i.e. the N900's card reader, can actually use those cards.

Could you please point me at one? The only Linux ExFAT driver I know is the proprietary one from Tuxera. Nevertheless I wouldn't want to use ExFAT anyway.

I really hope so. I'd be that someone if I just knew what to do with that microSDXC in case the N900 does not support it.

The new San disk 64GB micro sdxc card works in the samsung galaxy s, gs2, htc sensation.

according to these:

http://www.androidnz.net/2011/09/san...confirmed.html

http://androidforums.com/samsung-gal...ing-sgsii.html

But i heard its slower than it should be in these probly becuz its not designed for them.

So if it can work in those its possible it will work in the N900 without any modification, software updates.

I'd suggest trying it out and if it doesnt work atleast everybody with an N900 will know it wont work & you can just get a camera that uses Micro sdxc so it wouldnt be such a huge lost.

Any more on this?

I have one in my N900 right now and it works perfectly after formatting.

That sounds good! Can you please give a little more info on that?

1. Which card do you use? I'm not sure if other cards than the Sandisk were released since I created this topic.
2. Which file system do you use?
3. What transfer rates do you get?

1. Its the only 64GB Sandisk SDXC Micro SD card available.
2. I formatted it with the inbuilt file manager, so whatever the default format is. So far I have copied files up to 2.5gb on to it
3. Using the N900 as mass storage via windows 7, I Get 13.2mbps transfer speed (from a sony vaio z with ssd drive and usb 3)

Hey, AFAIK they're not available yet, but *should* be soon. Are You sure, that You haven't got 16Gb or less card, with false size specified? Only one way to check it, is actually filling it up with ~64 GB of files, and md5 summing, if they're not written only partially.

Many Chinese sellers are famous for "fake" high capacity cards/pendrives.

Erm, default format would be exFat - N900 shouldn't be able to mount it at all, at least without special software support. Are You sure (again) that we're talking about 64GB SDXC card?...
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BTW, I wonder, how speed limits of our (hardware) microSD interface looks. RAM "sticks" with microSD plug, anyone?