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RISCOS SD card compatibility list

Posted: Mon Nov 26, 2012 3:31 pm
by Tirpitz
I had got an idea to work out SD card compatibility list because it looks RISC OS is more squeamish for SDs than other systems.
Immediately I write my experience here.

1. Kingston SDHC HD Video 4 GB Class 4
2. Kingston SDHC HD Video 8 GB Class 4
In both cases boot with error message: " Machine Start up has not completed successfully: 'The disc is empty' ".

3. MicroSD 2 GB from my Nokia - Boot without problems.

Re: SD card compatibility list

Posted: Mon Nov 26, 2012 4:28 pm
by nr.
I'm using a 4GB SanDisk class 4 card. Totally reliable so far, despite numerous unplanned system restarts thanks to my programming abilities.

Re: SD card compatibility list

Posted: Mon Nov 26, 2012 4:43 pm
by notarat
Two notes:

1 - You may want to message an Admin to see if they can change the title of the thread to "RiscOS SD Compatibility List" (or something similar)

2 - San Disk 4GB Class 10 works fine too.

Re: SD card compatibility list

Posted: Mon Nov 26, 2012 4:52 pm
by Joe Schmoe
I seriously doubt you can establish a reliable link between brand name and usability on the Pi.

I'm sure there are a whole bunch of other variables at work, including (but, of course, not limited to):
1) Phase of the moon (i.e., just luck)
2) User error (a big one - caught me, for example, when I forgot to "sync" before removing the card)
3) card reader/writer dynamics. I.e., some card readers won't work with any card, some might work with card brand X on day Y, but not under other combinations, etc, etc.

Re: SD card compatibility list

Posted: Tue Nov 27, 2012 12:40 am
by theom
If it works, *SDIODevices will tell you what it actually is, rather than what's printed on the outside.

Re: SD card compatibility list

Posted: Tue Nov 27, 2012 1:53 pm
by Tirpitz
Joe Schmoe wrote:I seriously doubt you can establish a reliable link between brand name and usability on the Pi.

I'm sure there are a whole bunch of other variables at work, including (but, of course, not limited to):
1) Phase of the moon (i.e., just luck)
2) User error (a big one - caught me, for example, when I forgot to "sync" before removing the card)
3) card reader/writer dynamics. I.e., some card readers won't work with any card, some might work with card brand X on day Y, but not under other combinations, etc, etc.
I used standard Unix/Linux/Mac OS X procedure with command dd. It can happen, the system would not take all cards. It is not so new for me. I remember similar thing on Nokia 3650, not every MMC card worked correctly with this smartphone. User references there were very helpful.

Re: SD card compatibility list

Posted: Tue Nov 27, 2012 2:35 pm
by Joe Schmoe
Tirpitz wrote:
Joe Schmoe wrote:I seriously doubt you can establish a reliable link between brand name and usability on the Pi.

I'm sure there are a whole bunch of other variables at work, including (but, of course, not limited to):
1) Phase of the moon (i.e., just luck)
2) User error (a big one - caught me, for example, when I forgot to "sync" before removing the card)
3) card reader/writer dynamics. I.e., some card readers won't work with any card, some might work with card brand X on day Y, but not under other combinations, etc, etc.
I used standard Unix/Linux/Mac OS X procedure with command dd. It can happen, the system would not take all cards. It is not so new for me. I remember similar thing on Nokia 3650, not every MMC card worked correctly with this smartphone. User references there were very helpful.
There's no implication that you're a dummy. As I said, it caught me, too. I'm pretty sure that the first time I wrote the RISCOS image to the card, I forgot to run "sync" before removing the card. It can happen to anybody. FWIW, I've never had a problem writing a Linux image (knock wood, and all that), so I think there is something to what people are saying that, for whatever reason(s), the RISCOS image is more prone to this sort of problem. And, of course, it doesn't help that the thing boots and looks more or less normal (after you hit Cancel - to get past the error screen).

As I said in my first sentence, I just don't think it is a good idea to think that there is going to be a good correlation between experiential success and the brand name stamped on the card. As I'm sure you are aware, a lot of the time, there isn't really any difference from brand to brand; they all come from the same source(s) and each manufacturer just stamps their name onto it before offering it for sale.

Re: RISCOS SD card compatibility list

Posted: Tue Nov 27, 2012 4:46 pm
by Unhban
SD cards don't just have memory on them, some manufacturers put wear-levelling circuitry on too. I just wonder if it's this that is causing problems with RISC OS specifically? (or perhaps the ones that don't have this circuitry on?)

Wear-levelling wiki:

http://en.wikipedia.org/wiki/Wear_leveling

P.S. the smaller the SD card, and the more data on it, will get more 'wearing' than a large SD card with a small amount of data. For example, I have a 16GB card of which only 17% is data on it. This gives the wear-levelling circuitry more room to go at to spread data around the memory when it needs to, and consequently much less 'wearing'.

BTW, mine is a SANDISK ULTRA Class 10 card and have had no problems with RISC OS.

Unh.

Re: SD card compatibility list

Posted: Tue Nov 27, 2012 5:34 pm
by MegaGumbo
Joe Schmoe wrote:I seriously doubt you can establish a reliable link between brand name and usability on the Pi.

I'm sure there are a whole bunch of other variables at work, including (but, of course, not limited to):
1) Phase of the moon (i.e., just luck)
That's probably the most usual one. I have a SanDisk 4GB that used to be working until a few days ago. I've "nulled" it a hundred times, mkfs'ed it, almost did the nude dance around it howling at the moon - but every time I put an image on it and try to boot it now fails. Still works fine with my digicam though.

Re: RISCOS SD card compatibility list

Posted: Wed Nov 28, 2012 12:59 am
by bhtooefr
Grr... lost a post to a NetSurf crash... (seems it didn't like me dragging and dropping a text file into this field).

Anyway, my understanding is that critical Filecore structures are stored at the end of the volume, which would obviously be the last thing written by a sync or a proper umount. Those structures don't get written, the filesystem freaks out, and the end of that is quite predictable.

Here's the output of *SDIODevices on the card that I have working properly on a first-run Pi:

Bus Slt RCA Fun Description Capacity Vendor Product Rev Date
0 0 E624 0 SDHC card 3782 Mbytes SanDisk SD04G 8.0 2011-09

It's branded as a SanDisk SDHC Card, 4 GB, Class 4.

Re: RISCOS SD card compatibility list

Posted: Wed Nov 28, 2012 1:06 am
by pygmy_giant
Ive noticed that loss of power tends to corrupt SD cards more easily under RISC OS than Linux.

My understanding is that any incompatability issues not fixed by Pi firmware revisions between RISC OS and SD Card manufactures are down to the card's controller circuityry rather than the type of flash memory used.

I've heard that cards deemed safe can become unsafe if the card manufacturer chooses to change their circuit specs, so any list can only ever really be a guideline.

I'm using a SiliconPower Class 6 16gb card.

In truth, I've never found a card that doesn't work with the Pi - a list of non-working cards migh be shorter and more useful.