OESF Portables Forum
Everything Else => General Support and Discussion => Zaurus General Forums => Archived Forums => Accessories => Topic started by: SharpEnd on May 07, 2004, 05:54:14 pm
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Can someone point me to (or fill me in) a quick primer on SD versus CF memory cards? Which ones are better, more functional, etc. for the Z, and the pros and cons of each.
Can\'t wait to get my Z C860 next week!
Thanks!
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SD cards are smaller, slightly more expensive for equivalent storage (although this gap is shrinking fast), and access is somewhat slower. This can be a problem because sometimes movies have trouble playing from SD cards if the bitrate is too high. On the Zaurus, you can only use the SD slot for flash storage cards. The driver for the SD slot is binary only, which can be a problem if you want to experiment with alternate kernels.
CF cards are bigger, slightly cheaper per megabyte, and go up to much larger capacities. (I think the current max is 4GB, but it increases every year). You can even buy \"microdrives\" which are basically a standard hard drive shrunk down into a tiny package. CF is based on PCMCIA, which is a venerable technology invented for laptop expansion a very long time ago. The CF slot is useful for many more things besides storage - you can put all kinds of devices in there, network/wireless cards are just one common example.
Because the CF slot is so much more flexible, most people use the SD slot for holding a memory card with all the programs and data, and use the CF slot for other things like network access.
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did I just see a 12 GB flash? or was it 16GB? anyway, it was a cool $9999.99 etc.
To me, the $300 range is tops for storage cards. a $150 muvio is within that range :-)
Scott
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I saw that one too... 12 GB world\'s largest capacity and yep $9999 now they reduced the price of the 6 GB one from $7999 to $3999
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Um, I stand corrected. Hands up, everyone who has a ]4gig CF card.
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SD cards are smaller, slightly more expensive for equivalent storage (although this gap is shrinking fast), and access is somewhat slower. This can be a problem because sometimes movies have trouble playing from SD cards if the bitrate is too high. On the Zaurus, you can only use the SD slot for flash storage cards. The driver for the SD slot is binary only, which can be a problem if you want to experiment with alternate kernels.
Because the CF slot is so much more flexible, most people use the SD slot for holding a memory card with all the programs and data, and use the CF slot for other things like network access.
So I guess I need one of each? A CF card to store/load kernels, SD card for daily use while I have a CF wifi card in that slot?
Any brand SD or CF cards particularly better than others, or all they all pretty much the same?
Any recommendations for a low-power usage yet good function CF wifi card?
Thanks!!
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A lot of SD cards won\'t work with the Zaurus (or the Dell Axim or the Tungsten T3 or etc.). Worse, it isn\'t really possible to tell ahead of time which cards will and won\'t work - with the possible exception of that the ones which have been manufactured in Japan seem to work consistently. But you usually can\'t tell if the card was made in Japan until after you\'ve bought it, opened the package, and looked at the back of the chip. For gory details, see: http://sdprob.aximsite.com/ (http://sdprob.aximsite.com/). There\'s a list at http://sdprob.aximsite.com/theproblemlist.htm (http://sdprob.aximsite.com/theproblemlist.htm) which might give you an idea of which models are and aren\'t flakey. SanDisk cards are particularly bad.
Does anyone know if this is still an issue with recently manufactured Zauri?
patrick charles hayes
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A lot of SD cards won\'t work with the Zaurus (or the Dell Axim or the Tungsten T3 or etc.).
For gory details, see: http://sdprob.aximsite.com/ (http://sdprob.aximsite.com/). There\'s a list at http://sdprob.aximsite.com/theproblemlist.htm (http://sdprob.aximsite.com/theproblemlist.htm) which might give you an idea of which models are and aren\'t flakey. SanDisk cards are particularly bad.
Thanks, Patrick, for the tip and the link. Looks like the Lexar card that I was looking at is OK, as is Simpletech (which is supposed to be a very fast SD card, from what I\'ve read). Will look into it further before buying.
Any tips as to size to purchase, supposing that I\'m going to be flashing roms?
Mike
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Any tips as to size to purchase, supposing that I\'m going to be flashing roms?
Mike
I would make sure at least one card (either SD or CF) is 256mb or larger. With the C series Zs, you may find the need to do a NAND restore (http://www.zaurususergroup.com/modules.php?op=modload&name=phpWiki&file=index&pagename=NAND%20Flash%20Restore), and the NAND files are generally ]130mb. btw - I think people have had more luck with flashing with a CF than a SD card, but I could be completely wrong (someone please correct me!).
Also, you may want to check out the following How-To docs, good reading and more knowledge...
Compatibility and Support (http://www.zaurususergroup.com/modules.php?op=modload&name=phpWiki&file=index&pagename=Compatibility_And_Support)
SD and CF FAQ (http://www.zaurususergroup.com/modules.php?op=modload&name=phpWiki&file=index&pagename=SD%20And%20CF%20FAQ)
offroadgeek
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So after reading the FAQ, I\'m actually more confused as it mentioned that the Z can\'t take advantage of the extra speed of SD cards (is this accurate?). I\'m wondering if one SD card which is faster than another, or one CF card which is faster than another, is worth the price difference? Or just buy the cheapest card, because speed doesn\'t matter?
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\'m actually more confused as it mentioned that the Z can\'t take advantage of the extra speed of SD cards (is this accurate?).
I\'ve been wondering about that too!
Here\'s what I (think I) know: There\'s an older standard called MMC, which is the original basis for SD. MMC cards look just like SD cards, except they have 2 fewer pins and are a tiny bit thinner. They are also compatible with SD slots. (you can use an MMC card in the Zaurus just fine)
The SD card builds on the MMC standard, and features a slow compatibility mode where they mostly function like an MMC card. However, SD cards also support some faster transfer modes that aren\'t MMC compatible.
Now, some drivers apparently only support the slow MMC modes. The question is whether or not the Zaurus does this.
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I have been using both the Lexar and SanDisk SD cards, both 256mb. Not a problem with either one. I also have NOT had any luck trying to load a ROM image from SD, no problem on CF. Go figure. I understand that initially there was a quality control issue with the main factory that supplies these chips. Most prominent were the ones sold by SanDisk, they were the first to market, therefore the first to fail. Recent product has been quite good, although I dont know about the claims of speed as such.
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On my 5600, I was able to flash the ROM from an MMC card. I changed kernels and distributions several times with no problem.
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Although I had a lot of trouble with a 256MB SanDisk SD card, my new Kingston 512MB SD works perfectly for NAND Backups & Restores and installing new ROMs (I have tried Cacko and pdaXrom so far).
I recommend that when you buy a new card (either SD or CF) you do a badblock scan before using it. I had trouble with my SanDisk card since I first started using it but it wasn\'t until I did a badblock scan that I realised only the first 108MB was free of bad blocks! I partitioned the card so I could only use these first 108MB and the card worked perfectly. I returned the card to SanDisk, got my money back and bought a Kingston instead.
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C860 with 512Mb SanDisk secure digital card & 512Mb SanDisk CF card. No problems with either one so far (knock silicon!).
Bob W
Miami FL
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C860 with 512Mb SanDisk secure digital card & 512Mb SanDisk CF card. No problems with either one so far (knock silicon!).
I think I found a couple of bargains on SD cards:
Buy.com has the Simpletech Pro-X fast SD 256mb for $60.69 : http://www.buy.com/retail/product.asp?sku=...02&loc=101&sp=1 (http://www.buy.com/retail/product.asp?sku=10359102&loc=101&sp=1)
and Sandisk 512mb SD for $99.99 today only (assuming that this is the made in Japan model which works): http://www.buy.com/retail/clearance/dotd.a...14&sku=70012130 (http://www.buy.com/retail/clearance/dotd.asp?loc=114&sku=70012130)
(no connection to the seller - just passing on some deals - I grabbed one of the Simpletech cards)
Mike
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my 512mb lexar sd goes offline whenever I give it any sustained writes -- ie: whenever I write to it.
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my 512mb lexar sd goes offline whenever I give it any sustained writes -- ie: whenever I write to it.
Is it a \"made in Japan\" model, or made in Singapore?
Look here, as someone posted earlier: http://sdprob.aximsite.com/theproblemlist.htm (http://sdprob.aximsite.com/theproblemlist.htm)
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I have tested several sd and cf cards for speed, and I have not found a card that will do more than 1mb per second sustained on either a 5500 or an slc760.
the badged standard lexar 256 performs at the same speed as a badged 32X lexar 256mb card on my zaurus, but not on my PC!
In my usb2 card reader the 32x card wins hands down!
Anybody who has a card (cf or sd) that can achieve a sustained throughput of more than 1 mbyte per second in a zaurus then I want to know, as I will buy one.
The lexar 32X that I tested was supposed to go faster than 9mbytes per second. But it got no furthet than 1mb/sec in my tests on both zauri and the c760 definately out performed the 5500 with the same card.
CF also always outperoms sd, in my tests, but never crosses the 1mb/ps threshold leaving me to believe that either the cards are not fully wired or the zaurus bus is not upto the job.
Prove me wrong, if you can! I would love to have a faster card in my zaurus.
Peter
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CF also always outperoms sd, in my tests, but never crosses the 1mb/ps threshold leaving me to believe that either the cards are not fully wired or the zaurus bus is not upto the job.
Peter
Thanks for the info, Peter, this is good to know.
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I get around 1600 kB/s with both a panasonic and a simpletech pro-x 256MB SD card when I dd 10MB from /dev/zero to /mnt/card. Is there a better way to measure the speed?
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I recommend that when you buy a new card (either SD or CF) you do a badblock scan before using it. I had trouble with my SanDisk card since I first started using it but it wasn\'t until I did a badblock scan that I realised only the first 108MB was free of bad blocks! I partitioned the card so I could only use these first 108MB and the card worked perfectly. I returned the card to SanDisk, got my money back and bought a Kingston instead.
(newbie question, sorry )
How do you do a \"badblock scan\" ? Directly from the Zaurus, ot from a PC through a card reader ?
Thanks,
fp
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If you format it ext2, you can do the badblocks scan while formatting. Use the -j option.
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Thanks !
Is there any way to check an existing FAT32-formatted card, without erasing it ?
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I get around 1600 kB/s with both a panasonic and a simpletech pro-x 256MB SD card when I dd 10MB from /dev/zero to /mnt/card. Is there a better way to measure the speed?
That\'s a good choice as /dev/zero is not going to be a bottle neck in terms of read. However 10mb may not be a large enough file for a true test.
You have 64mb ram, some of that will be used as buffer cache so to defeat the effects of that you may have to write a larger file.
Just to prove the point, post the exact command you ran and I will try it on my two sd cards. Then the only difference would be the make of sd card in our test.
Peter
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I have used 256 MB SD card made by Hagiwara Sys-Com from Japan as my system backup disk since 09/2003. I have used Sandisk CF cards, ranging from 32 MB to 256 MB, since 2001 for various PDA.
I have no p reliability and quality problem with memory cards from both bands.
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I get around 1600 kB/s with both a panasonic and a simpletech pro-x 256MB SD card when I dd 10MB from /dev/zero to /mnt/card. Is there a better way to measure the speed?
That\'s a good choice as /dev/zero is not going to be a bottle neck in terms of read. However 10mb may not be a large enough file for a true test.
You have 64mb ram, some of that will be used as buffer cache so to defeat the effects of that you may have to write a larger file.
Just to prove the point, post the exact command you ran and I will try it on my two sd cards. Then the only difference would be the make of sd card in our test.
Peter
The following is with a vfat-formatted 256MB Simpletech Pro-X SD card. I include a sync command into the timing to exclude buffer effects.
root@zaurus(pts0):~# time sh -c \'dd if=/dev/zero of=/mnt/card/dump bs=1024k count=10; sync\'
10+0 records in
10+0 records out
real 0m5.942s
user 0m0.060s
sys 0m5.880s
root@zaurus(pts0):~# rm -f /mnt/card/dump
root@zaurus(pts0):~# time sh -c \'dd if=/dev/zero of=/mnt/card/dump bs=1024k count=20; sync\'
20+0 records in
20+0 records out
real 0m11.741s
user 0m0.040s
sys 0m11.680s
root@zaurus(pts0):~# rm -f /mnt/card/dump
root@zaurus(pts0):~# time sh -c \'dd if=/dev/zero of=/mnt/card/dump bs=1024k count=40; sync\'
40+0 records in
40+0 records out
real 0m23.596s
user 0m0.040s
sys 0m8.430s
root@zaurus(pts0):~# rm -f /mnt/card/dump
root@zaurus(pts0):~# time sh -c \'dd if=/dev/zero of=/mnt/card/dump bs=1024k count=80; sync\'
80+0 records in
80+0 records out
real 0m47.895s
user 0m0.010s
sys 0m26.370s
Not sure why the sys time is too small for the larger file sizes. The real time is correct. These values are reproducible within a few percent.
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root@zaurus(pts0):~# rm -f /mnt/card/dump
root@zaurus(pts0):~# time sh -c \'dd if=/dev/zero of=/mnt/card/dump bs=1024k count=80; sync\'
80+0 records in
80+0 records out
real 0m47.895s
user 0m0.010s
sys 0m26.370s
Zazz, thanks for that, I get :-
real 1m41.504s
user 0m0.040s
sys 1m28.640s
So your card is indeed over twice the speed as my lexar.
I still doubt that that is anywhere near the mf quoted speed though, do you know what that is?
Also, what zaurus/rom/kernel was this on?
*EDIT*
Just done a search, c860 with pdaxrom, was it overclocked at all as that does make a difference.
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I still doubt that that is anywhere near the mf quoted speed though, do you know what that is?
The manufacturer hyped speed is up to 10MB/s. I\'m not sure if the card itself is the bottleneck or rather the bus speed of the Z. Does anyone have a faster card?
Also, what zaurus/rom/kernel was this on?
*EDIT*
Just done a search, c860 with pdaxrom, was it overclocked at all as that does make a difference.
Yes, C860 with pdaxrom, not overclocked.
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Yes, C860 with pdaxrom, not overclocked.
Just to rule out any sash type jigory pokery optimization stuff, could you possible test your internal flash?
I get 42.120s for 80m, 23.465s for 40m and 4.940s for 10mb.
I used the same command line just changed count= to 10,40, and 80.
I did a few as on the pdaxrom I doubt you will have 80mb free.
Oh, the sync line was left in as well.
Cheers,
Peter
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Just to rule out any sash type jigory pokery optimization stuff, could you possible test your internal flash?
I get 42.120s for 80m, 23.465s for 40m and 4.940s for 10mb.
I used the same command line just changed count= to 10,40, and 80.
Due to space constraints I can only do the 10MB test (even though I have a single 121MB partition)... I get 4.85 +- 0.10 sec.
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I get 4.85 +- 0.10 sec.
OK, thats good enough for me it is close enough to be classed as the same speed.
I take it you can use it as ext2/3 without any nasty going read only issues or io error issues? If so my next sd card purchase will be one of these, unless anybody can beat 1.6mb/sec
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My own small contribution to the cause:
SanDisk SDSDB-512-768 Secure Digital Card
time sh -c \'dd if=/dev/zero of=/mnt/card/dump bs=1024k count=80; sync\'
real 0m46.384s
user 0m0.020s
sys 0m27.950s
replicates +/- 2-3 sec \"real\"
SanDisk SDCFB-512-768 Compact Flash Card
time sh -c \'dd if=/dev/zero of=/mnt/cf/dump bs=1024k count=80; sync\'
real 0m24.284s
user 0m0.020s
sys 0m4.470s
replicates +/- ~2 sec \"real\"
Internal Flash
time sh -c \'dd if=/dev/zero of=/home/zaurus/Documents/dump bs=1024k count=10; sync\'
real 0m4.648s
user 0m0.050s
sys 0m4.580s
time sh -c \'dd if=/dev/zero of=/home/zaurus/Documents/dump bs=1024k count=20; sync\'
real 0m9.248s
user 0m0.030s
sys 0m9.080s
time sh -c \'dd if=/dev/zero of=/home/zaurus/Documents/dump bs=1024k count=40; sync\'
real 0m18.523s
user 0m0.030s
sys 0m18.170s
time sh -c \'dd if=/dev/zero of=/home/zaurus/Documents/dump bs=1024k count=80; sync\'
real 0m39.240s
user 0m0.030s
sys 0m36.430s
replicates well
The 2 storage cards were both purchased locally on impulse because they had significantly discounted prices (after the %#$@*&! MIRs, of course). No obvious pedigrees that the packaging indicates.
YMMV
Bob W
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Thanks !
Is there any way to check an existing FAT32-formatted card, without erasing it ?
Yes, just go to a terminal window, su to root and type the following:
umount /mnt/card
badblocks -sv /dev/mmcda
(Note /dev/mmcda instead of /dev/mmcda1. You can scan just /dev/mmcda1 if you like, but using /dev/mmcda will scan the whole card including data outside of the first partition.)
If this shows up bad blocks, you can use the -o option to write a list of bad blocks to a file, e.g.:
cd /tmp
badblocks -svo sd_card_badblocks /dev/mmcda
You can then use this file to tell mkfs which blocks to skip (has the same effect as running mkfs with -c but means you don't have to scan the card again).
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Hi Guys,
Just gotten my C860 directly from Japan and have performed most of the conversion to English from the original Sharp ROM 1.40JP.
I have also bought a CF Kingston 512MB Elite PRo given as 5MB/s for writing (2X std CF speed).
The CF works fine with the Z already the overall OS, but, no way to get NAND backup done. From the service menu, the Z starts the backup process but never hits the point when you have to respond yes before it goes. Removing the CF showed that the Z is trying to test/initialize the CF card.
I tried with another Kingston 512MB std speed and the backup worked (I have not tested any restore yet).
At this point, I think that the soft performing the NAND backup is not able to handle the High Speed CF but would like to have confirmation.
Anybody of you has a Kingston Elite Pro CF and tried already NAND Backup on it?
Thanks
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my digicam came with a 32 MB SD card, can i use a CF card in the same slot?