Date: Thu, 23 Mar 2017 09:07:32 -0600 From: Ian Lepore <ian@freebsd.org> To: "Dr. Rolf Jansen" <rj@obsigna.com>, freebsd-arm@freebsd.org Subject: Re: Identifying counterfeit microSD cards on a Beaglebone Black Message-ID: <1490281652.58015.71.camel@freebsd.org> In-Reply-To: <70C95FC9-4B0A-4DA4-9857-EFAF41522D1B@obsigna.com> References: <D08E6528-56E6-4229-8722-D87116B8064D@obsigna.com> <CANCZdfo97-iFg4zLxbyQhv9rPrd8eU5rN-mzDL5wz3xj6XxrsQ@mail.gmail.com> <A633D336-2581-4C51-A3C9-7AFD0ABB9E9F@obsigna.com> <1489864043.40576.219.camel@freebsd.org> <16B03E70-00E6-4C17-9A9A-8601F4C07364@obsigna.com> <2F7D5F42-E50A-4761-9EEC-DC873BD7D0AB@obsigna.com> <CAB=2f8wR57ip7gUVGQqHNAzCHq-qiC8nwVG1%2BASu1N3kCcKrEQ@mail.gmail.com> <70C95FC9-4B0A-4DA4-9857-EFAF41522D1B@obsigna.com>
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On Thu, 2017-03-23 at 00:42 -0300, Dr. Rolf Jansen wrote: > Am 21.03.2017 um 13:25 schrieb Luiz Otavio O Souza <lists.br@gmail.co > m>: > > > > On 19 March 2017 at 18:45, Dr. Rolf Jansen wrote: > > > > > > Am 18.03.2017 um 21:30 schrieb Dr. Rolf Jansen: > > > > > > > > Am 18.03.2017 um 16:07 schrieb Ian Lepore: > > > > > > > > > > On Sat, 2017-03-18 at 15:03 -0300, Dr. Rolf Jansen wrote: > > > > > > > > > > > > Am 18.03.2017 um 12:30 schrieb Warner Losh: > > > > > > > > > > > > > > > > > > > > > On Sat, Mar 18, 2017 at 8:44 AM, Dr. Rolf Jansen > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > I bought a 16 GB microSDHC SanDisk chip rated at 4 MB/s > > > > > > > > write > > > > > > > > speed for use with my Beaglebone Black. > > > > > > > > > > > > > > > > The internal flash offers practical write speeds in the > > > > > > > > range of > > > > > > > > 2 to 3 MB/s when copying data to it from a NFSv4 volume > > > > > > > > depending > > > > > > > > on the size of the files being copied. Executing the > > > > > > > > same copy > > > > > > > > operation with said microSDHC card as the target I see > > > > > > > > only 0.1 > > > > > > > > to 0.2 MB/s (less than 1/10). > > > > > > > > > > > > > > > > I suspect now that I got a counterfeited card. Before I > > > > > > > > dump it, > > > > > > > > I would like to run a definitive non-destructive test, > > > > > > > > preferably > > > > > > > > on the Beaglebone Black, and I would like to ask you > > > > > > > > for > > > > > > > > suggestions. > > [picking a random message to reply] > > > > I just saw an email from SanDisk support (whatever this means) > > where > > they claim the only supported model for this kind of use is the > > high-endurance series: > > https://www.sandisk.com/home/memory-cards/microsd-cards/high-endura > > nce-microsd > > > > This same email says that running any kind of OS in any of the > > other > > card models automatically breaks the warranty. > Luiz, thank you very much for the note. Do you know, whether this > high endurance XC card is compatible with the Beaglebone Black? > > Best regards > > Rolf I would assume that it is, they're typically just standard sd cards with flash arrays based on SLC technology and with a lot of extra space for reassigning bad blocks (a card that claims 8gb capacity could actually have 4x that many blocks or more available internally). But be aware that high-endurance or industrial-rated cards can be very expensive. I think at work we pay around $40 each for industrial-rated 8gb cards. (One of them was included in those test results I posted, and the performance was among the best, at least you get something for all that extra money.) -- Ian
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