MicroSD - Revision history

Qwakaw: /* Importent features */

2010-06-10T12:43:37Z

‎Importent features

Glenn: /* Use */ more

2010-01-17T13:53:48Z

‎Use: more

Glenn: chg

2010-01-17T13:52:35Z

chg

Glenn: ==External links==

2010-01-17T13:42:49Z

==External links==

Glenn: /* References */ linkchg

2010-01-17T13:32:44Z

‎References: linkchg

Glenn: /* References */ more

2010-01-17T13:28:21Z

‎References: more

Glenn: /* References */ more

2010-01-17T13:17:09Z

‎References: more

Glenn: /* References */ chg

2010-01-17T13:16:07Z

‎References: chg

Glenn: /* References */ chg

2010-01-17T13:15:26Z

‎References: chg

Glenn: /* References */ more

2010-01-17T13:14:47Z

‎References: more

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 A list of supported cards can be found at [[Supported microSD cards]].
-==Importent features==
+==Important features==
-Importent note: [http://en.wikipedia.org/wiki/Wear_levelling Wear-leveling] and ECC error correction and detection is not part of the SD card specification (version 2.0 SDHC), so please check for yourself that the SD(HC)-card support and use:
+Important note: [http://en.wikipedia.org/wiki/Wear_levelling Wear-leveling] and ECC error correction and detection is not part of the SD card specification (version 2.0 SDHC), so please check for yourself that the SD(HC)-card support and use:
 *built-in ECC error correction and detection
 *Wear Leveling technology
 If the manufacturer advertises the card with e.g. 1,000,000 hours [http://en.wikipedia.org/wiki/Mean_time_between_failures MTBF], it might be a strong indication that the above features are used.
-Other importent specifications are:
+Other important specifications are:
 *Low power consumption
 *Number of insertions the card endures - 10,000 seems to be good quality.

@@ Line 17: / Line 17: @@
 ==Use==
-*A log-structured file system (e.g. [[NILFS2]]) ought to be a good choice because of the continuous snapshotting.
+*A log-structured file system (e.g. [[NILFS2]]) when available, ought to be a good choice because of the continuous snapshotting.
 ==References==

@@ Line 15: / Line 15: @@
 *Number of insertions the card endures - 10,000 seems to be good quality.
 *Total I/O operations per second
 ==References==
@@ Line 22: / Line 25: @@
 ==External links==
 *MicroSD(HC) flash cards can be tested via a USB flash adaptor and H2testw. Please backup your data before testing: [http://sosfakeflash.wordpress.com/2008/09/02/h2testw-14-gold-standard-in-detecting-usb-counterfeit-drives/ September 2, 2008, sosfakeflash.wordpress.com: H2testw 1.4 – Gold Standard In Detecting USB Counterfeit Drives], [http://www.bloggersbase.com/computers/h2testw-fix-usb/ bloggersbase.com: H2testw - Fix Your USB!] Quote: "...H2testw was developed to test USB sticks for various kinds of errors. It can also be used for any other storage media like memory cards, internal and external hard drives and even network volumes...", [http://www.heise.de/software/download/h2testw/50539 H2testw 1.4]
 [[Category:MicroSD| ]]

@@ Line 20: / Line 20: @@
 *[[MicroSD]](HC) cards are a sort of a SSD: [http://robert.penz.name/137/no-swap-partition-journaling-filesystem-on-a-ssd/ December 7, 2008, robert.penz.name:  No SWAP Partition, Journaling Filesystems, … on a SSD?] Quote: "...They assume perfect wear leveling...We stay also with the 2 million cycles and assume a 16GB SSD *With 50 MByte/sec we get 20 years! *With 2 MByte/sec we get 519 years! *And even if we reduce the write cycles to 100.000 and write with 2 MByte/sec all the time we’re at 26 years!!...1.  Never choose to use a journaling file system on the SSD partitions: Bullshit, you’re just risking data security. Stay with ext3...7. One more thing to consider is that flash-devices handle their space in blocks. The blocksize typically varies between 16KB and 512 KB. Therefore writing one byte may cause erase and rewrite of up to 512KB..."
 *'''Please note: SDHC-cards test - not ''Micro''SDHC-cards''': [http://www.tomshardware.com/charts/sdhc-memory-card-charts/File-Server-Benchmark-Pattern,865.html tomshardware.com: SDHC Memory Card Charts > File Server Benchmark Pattern: File Server Benchmark Pattern] Quote: "...IOMeter 2003.05.10 (Total I/O operations per second for Queuedepth 1 - 64)...", [http://www.tomshardware.com/charts/sdhc-memory-card-charts/benchmarks,40.html All SDHC Memory Card Charts]
 *A log-structured file system (e.g. [[NILFS2]]) ought to be the best for flash cards: [http://www.sunhelp.org/pipermail/geeks/2008-February/061492.html 2008 (geeks) Flash wear leveling] Quote: "...We tested several file systems (ext2/3, xfs, reiserfs, FAT, ...) and finaly gave up...and developed an application speciffic log structured file system in userland..."
 *MicroSD(HC) flash cards can be tested via a USB flash adaptor and H2testw. Please backup your data before testing: [http://sosfakeflash.wordpress.com/2008/09/02/h2testw-14-gold-standard-in-detecting-usb-counterfeit-drives/ September 2, 2008, sosfakeflash.wordpress.com: H2testw 1.4 – Gold Standard In Detecting USB Counterfeit Drives], [http://www.bloggersbase.com/computers/h2testw-fix-usb/ bloggersbase.com: H2testw - Fix Your USB!] Quote: "...H2testw was developed to test USB sticks for various kinds of errors. It can also be used for any other storage media like memory cards, internal and external hard drives and even network volumes...", [http://www.heise.de/software/download/h2testw/50539 H2testw 1.4]
 [[Category:MicroSD| ]]

@@ Line 20: / Line 20: @@
 *[[MicroSD]](HC) cards are a sort of a SSD: [http://robert.penz.name/137/no-swap-partition-journaling-filesystem-on-a-ssd/ December 7, 2008, robert.penz.name:  No SWAP Partition, Journaling Filesystems, … on a SSD?] Quote: "...They assume perfect wear leveling...We stay also with the 2 million cycles and assume a 16GB SSD *With 50 MByte/sec we get 20 years! *With 2 MByte/sec we get 519 years! *And even if we reduce the write cycles to 100.000 and write with 2 MByte/sec all the time we’re at 26 years!!...1.  Never choose to use a journaling file system on the SSD partitions: Bullshit, you’re just risking data security. Stay with ext3...7. One more thing to consider is that flash-devices handle their space in blocks. The blocksize typically varies between 16KB and 512 KB. Therefore writing one byte may cause erase and rewrite of up to 512KB..."
 *'''Please note: SDHC-cards test - not ''Micro''SDHC-cards''': [http://www.tomshardware.com/charts/sdhc-memory-card-charts/File-Server-Benchmark-Pattern,865.html tomshardware.com: SDHC Memory Card Charts > File Server Benchmark Pattern: File Server Benchmark Pattern] Quote: "...IOMeter 2003.05.10 (Total I/O operations per second for Queuedepth 1 - 64)...", [http://www.tomshardware.com/charts/sdhc-memory-card-charts/benchmarks,40.html All SDHC Memory Card Charts]
-*A log-structured file system (e.g. [[Booting_from_SD#NILFS|NILFS2]]) ought to be the best for flash cards: [http://www.sunhelp.org/pipermail/geeks/2008-February/061492.html 2008 (geeks) Flash wear leveling] Quote: "...We tested several file systems (ext2/3, xfs, reiserfs, FAT, ...) and finaly gave up...and developed an application speciffic log structured file system in userland..."
+*A log-structured file system (e.g. [[NILFS2]]) ought to be the best for flash cards: [http://www.sunhelp.org/pipermail/geeks/2008-February/061492.html 2008 (geeks) Flash wear leveling] Quote: "...We tested several file systems (ext2/3, xfs, reiserfs, FAT, ...) and finaly gave up...and developed an application speciffic log structured file system in userland..."
 *MicroSD(HC) flash cards can be tested via a USB flash adaptor and H2testw. Please backup your data before testing: [http://sosfakeflash.wordpress.com/2008/09/02/h2testw-14-gold-standard-in-detecting-usb-counterfeit-drives/ September 2, 2008, sosfakeflash.wordpress.com: H2testw 1.4 – Gold Standard In Detecting USB Counterfeit Drives], [http://www.bloggersbase.com/computers/h2testw-fix-usb/ bloggersbase.com: H2testw - Fix Your USB!] Quote: "...H2testw was developed to test USB sticks for various kinds of errors. It can also be used for any other storage media like memory cards, internal and external hard drives and even network volumes...", [http://www.heise.de/software/download/h2testw/50539 H2testw 1.4]
 [[Category:MicroSD| ]]

@@ Line 21: / Line 21: @@
 *'''Please note: SDHC-cards test - not ''Micro''SDHC-cards''': [http://www.tomshardware.com/charts/sdhc-memory-card-charts/File-Server-Benchmark-Pattern,865.html tomshardware.com: SDHC Memory Card Charts > File Server Benchmark Pattern: File Server Benchmark Pattern] Quote: "...IOMeter 2003.05.10 (Total I/O operations per second for Queuedepth 1 - 64)...", [http://www.tomshardware.com/charts/sdhc-memory-card-charts/benchmarks,40.html All SDHC Memory Card Charts]
 *[http://www.sunhelp.org/pipermail/geeks/2008-February/061492.html 2008 (geeks) Flash wear leveling] Quote: "...We tested several file systems (ext2/3, xfs, reiserfs, FAT, ...) and finaly gave up...and developed an application speciffic log structured file system in userland..."
-*MicroSD(HC) can be tested via a USB flash adaptor and H2testw. Please backup your data before testing: [http://sosfakeflash.wordpress.com/2008/09/02/h2testw-14-gold-standard-in-detecting-usb-counterfeit-drives/ September 2, 2008, sosfakeflash.wordpress.com: H2testw 1.4 – Gold Standard In Detecting USB Counterfeit Drives], [http://www.bloggersbase.com/computers/h2testw-fix-usb/ bloggersbase.com: H2testw - Fix Your USB!], [http://www.heise.de/software/download/h2testw/50539 H2testw 1.4]
+*MicroSD(HC) flash cards can be tested via a USB flash adaptor and H2testw. Please backup your data before testing: [http://sosfakeflash.wordpress.com/2008/09/02/h2testw-14-gold-standard-in-detecting-usb-counterfeit-drives/ September 2, 2008, sosfakeflash.wordpress.com: H2testw 1.4 – Gold Standard In Detecting USB Counterfeit Drives], [http://www.bloggersbase.com/computers/h2testw-fix-usb/ bloggersbase.com: H2testw - Fix Your USB!], [http://www.heise.de/software/download/h2testw/50539 H2testw 1.4]
 [[Category:MicroSD| ]]