Rockbox and SDXC

[clumsymoe]

So here in a little while we should start seeing microSDXC cards, which means we can start trying to fit them in our tiny PMPs. From what I know, SDXC is basically just a different layout of all the little magic legos inside the card, so it would only need firmware to support it, not a different controller?

Basically, would be be able to have SDXC support on a device that doesn't normally support it (Clip+) thanks to rockbox?

[torne]

There are two kinds of SDXC cards: one kind is just an SDHC card with a higher capacity which is supposed to come preformatted as exFAT. This should work with Rockbox just fine as long as you reformat it as FAT32. The other kind is a "real" SDXC card which are faster but are not electrically compatible with SD/SDHC readers. This won't work.

[Yakuman]

Well, the 64gb SDXC cards have dropped (somewhat) in price. Amazon has them for $160. http://amzn.to/AdpGtD

Is there any word as to whether they will work in Rockbox, now or in the future?

Edit: What about an Android phone that is known to be SDXC capable. That would work, right?

Or what about a future mp3 player that uses the discs?

I'm concerned that Rockbox would have to work with SDXC soon, as it becomes standardized on portable devices.

[evilnick]

I imagine that providing SDXC becomes used for enough devices that RB can run on then it will become supported. Although as with anything open-source, these requests don't come with an ETA.

On an Android phone, my assumption is that since the phone itself handles the SDXC card then this should work with RB on that phone (but that's very much an assumption).

If/when SDXC becomes more prevalent on the devices that RB runs on then I'd be frankly shocked if RB did not support it.

[bluebrother]

On an Android phone, my assumption is that since the phone itself handles the SDXC card then this should work with RB on that phone (but that's very much an assumption).

Yes, as in any hosted environment Rockbox does not do the "bare" filesystem operations. Right now there's even this situation: on Android the SD card is (usually) FAT, but everything else (usually) uses a different file system. Rockbox does not know about those since those are handled by the OS (i.e. Android)

If/when SDXC becomes more prevalent on the devices that RB runs on then I'd be frankly shocked if RB did not support it.

You might want start being shocked then.

For SDXC cards, there are two types available. Version 3.0 is somewhat compatible to SDHC: it can physically be used with SDHC hosts. However, the SDXC standard requires those cards to use the exFAT filesystem which Rockbox does not support, and is unlikely to support since it's proprietary and requires a fee to be used. One can reformat such a card to FAT32. In that case it should work with Rockbox (except that Rockbox cannot use the new features of SDXC, as is true with any SDXC card reader). However, other devices (like digital cameras) might not be able to handle an SDXC card that uses a different filesystem than exFAT.

The newer type of SDXC (haven't found the spec version right now, I guess it's 3.1) is not compatible to SDHC so it is not possible to support such cards unless the player has an SDXC host interface. Given that evolution of music players goes rather into the everything-device direction (like Android and iOS) I doubt a player with SDXC host will ever be available. But with the (likely) evolution of Rockbox to running as an app this won't be much of concern anymore.

If a player comes out that has an SDXC host interface it might be supported, but supporting exFAT is highly unlikely.

(and as a side note, this SDXC thing is -- from a technical point of view -- unnecessary when it comes to storage sizes. SDHC changed the addressing compared to SD, and the protocol does not limit the maximum size to 32GiB. However, the SDHC spec limits the maximum size to 32GiB. In theory it's perfectly possible to build a 128GiB SDHC card, but that's out of spec so this will never happen. Plus, vendors need a reason for us to buy new card readers and other devices ...)

[torne]

The interface change in the later revision of the SDXC spec is about improving performance, not capacity, so hey

[saratoga]

I thought UHS-II (the v4.0 300MB/s) mode was backwards compatible with SDHC, just at a lower clock speed and without using the new 8 bit mode (or whatever it is). 

[evilnick]

Bluebrother:  Consider me then!