Igor Posted April 7, 2017 Posted April 7, 2017 During spring cleaning I found Nokia 128Mb SD card and I could not resist to make the standard test ... which took around one hour to finish I expect worse. Spoiler Command line used: iozone -e -I -a -s 100M -r 4k -r 16k -r 512k -r 1024k -r 16384k -i 0 -i 1 -i 2 Output is in kBytes/sec Time Resolution = 0.000001 seconds. Processor cache size set to 1024 kBytes. Processor cache line size set to 32 bytes. File stride size set to 17 * record size. random random kB reclen write rewrite read reread read write 102400 4 2612 2621 4559 4563 3197 48 102400 16 2598 2592 6645 6622 5809 201 102400 512 2538 2594 7615 7615 7579 1825 102400 1024 2541 2601 7641 7646 7628 2142 102400 16384 2537 2608 7694 7696 7694 2586
martinayotte Posted April 7, 2017 Posted April 7, 2017 That makes me remembering when I purchased my first digital camera : 1Mpix per picture, 32MB FullSD. cost me $1000 ... 1
hojnikb Posted April 7, 2017 Posted April 7, 2017 I think i still have 32MB MMC card lying around somewhere As far as i recall, it was very slow even at the time
manuti Posted April 10, 2017 Posted April 10, 2017 On 7/4/2017 at 10:43 PM, hojnikb said: 32MB See your 32 and go down to 16MB 1
technik007_cz Posted April 10, 2017 Posted April 10, 2017 On 07/04/2017 at 6:38 PM, Igor said: During spring cleaning I found Nokia 128Mb SD card I needed small sized cards for nfs boot. I ordered 10pcs of them on Aliexpress and received exactly same ones (Nokia 128MB) probably ripped off old phones :-). 1 could not initialize but rest of them passed badblock test (I received refund for bad piece without any problem). Than I ordered cheaper ones, 10 pcs again. I got new cards with orange/white colour. 1 could not innitialize => rubbish 2 did not pass test in external but passed test in internal reader => ??rubbish 2 did not pass neither in external or internal reader => rubbish So keep this card :-) it still has value.
tkaiser Posted April 10, 2017 Posted April 10, 2017 10 minutes ago, technik007_cz said: badblock test Better use F3 or H2testw instead: https://docs.armbian.com/User-Guide_Getting-Started/#how-to-prepare-a-sd-card Badblocks semantics are pretty useless on flash media implementing FTL (flash translation layer) since there's no real mapping between physical flash cells and logical blocks. F3 or H2testw do a better job here and sellers usually accept their logs/screenshots to get a refund/replacement. BTW: both tools reports writing and reading speeds which is also interesting since some flash media do 60MB/s fine... but just for a couple of minutes and then slow down. Another good reason to get a refund/replacement! And here is a related but rather lenghty discussion regarding SD card 'problems' (that are on some platforms often caused by the other standard SBC problem: underpowering, especially Raspberries a few years ago suffered from SD card corruption related to undervoltage): http://tech.scargill.net/a-question-of-lifespan/
technik007_cz Posted April 10, 2017 Posted April 10, 2017 9 minutes ago, tkaiser said: Better use F3 or H2testw instead: I run test on debian distro at this moment. (I can switch on windows but only if it is question of life or die). Thank you for keeping me updated I gonna try f3.
technik007_cz Posted April 10, 2017 Posted April 10, 2017 @tkaiser I tested 10pcs of 128MB sized and there is result. I needed insert card in and just only press enter in opened terminal screen (with command ready like badblocks -wsv /dev/mmcblk0), replace card and press again until no more cards left. Badblocks found 5 cards with errors and i decided just for case test good ones with f3. I must mount card, change directory, write test data, unmount, unplug it, plug it again. (I tried test on cards marked bad by badblocks and sometimes it did not find error without replugging it !!!) and make same procedure .. mount card, change directory and run reading test of previously data. And result of f3 test on "badblocks" cards marked ok? F3 did not find any error. Sorry F3 is not user friendly and I am definitely staying with "badblocks -wsv" which is easier to operate for me.
tkaiser Posted April 10, 2017 Posted April 10, 2017 1 hour ago, technik007_cz said: Sorry F3 is not user friendly and I am definitely staying with "badblocks -wsv" which is easier to operate for me Well, you're free to do whatever you want, even fooling yourself For anyone else who stumbles accross this: badblocks is absolutely useless when it's about flash media you bought recently (SD cards, SSDs, USB thumb drives and so on). If you bought really cheap old crap cards somewhere it might blame them correctly as bad but it it's not possible to check for the real problems we face with SD cards today: Checking fraud/counterfeit cards: http://www.happybison.com/reviews/how-to-check-and-spot-fake-micro-sd-card-8/ This is only possible by writing random data patterns to the card and then read all of them back. Takes some time but it's strongly recommended to test immediately with every flash based media you buy. H2testw is easy to use on Windows, F3 is easy to use within Armbian (we automated that for you so in case you forgot to check your card directly after purchase just let 'armbianmonitor -c $HOME' run) Again: badblocks works fine with spinning rust but is absolutely useless to check flash based media: http://git.net/ml/zfs-discuss/2014-10/msg00312.html The underlying technology has to be considered and then certain tools/strategies that worked fine for decades are of no use any more. Same for example with 'RAID 1' many people seem to love. Useful with HDDs, not that much with SD cards and an attempt to fool yourself when done with 2 SSD of same type.
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