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Old August 24th 18, 07:21 AM posted to alt.comp.hardware
VanguardLH[_2_]
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Default SD card problems

Mike S wrote:

SanDisk Ultra 64GB microSDXC


https://www.sandisk.com/home/memory-...-microsd-48mbs

They only list the read speed (48 MB/s), not the write speed. All they
mention in the notes is "write speeds lower". Yeah, right, very vague.
They lie about the read speed by not mentioning burst mode became
available in USB 3.0 which your USB 2.0 controller doesn't support; see
http://www.techdesignforums.com/prac...e/use-usb-3-0/. So you
don't really know the read spec of that card when used with USB 2.0 and
they say NOTHING about its write spec. Many users focus only on the
capacity of the card, not its read and write speeds, so they end up with
a slow card. You are saving files to the card which means you are
writing to the card.

https://www.pcmag.com/article2/0,2817,2393486,00.asp

That author said he got 13.5 MB/s for write speed; however, he never
mentioned the size of the files (to determine if they were under the
burst mode size or larger) or if he use USB 2.0 or 3.0.

https://www.tweaktown.com/reviews/67...iew/index.html

That review is for the larger cards. However, note the change in read
and write speeds under the different test modes. Tiny files don't fare
as well for transfer speed on flash media. You didn't mention the size
of your music files, or how many files you were writing at a time.
https://crystalmark.info/en/software...k-main-window/
gives info on choosing number of test runs (for averaging their
results), test size, and a short description of each test type.

You did not mention how you were saving (writing) the files. Were you
using Windows Explorer, some music library software, or what? Was the
data bus quiescent, so the only data traffic was for the file copying?
You mention "SIIG USB 2.0 Multi Card Reader/Writer" for the card reader
but not its model number. I don't know if that comes with any software.
I remember a USB HDD docking station that came with speed-up software
that did just the opposite. Uninstalling the software got transfer
speeds more consistently higher. I didn't see any software downloads at
http://www.siig.com/download/search/...d=JU-MR0C12-S1 (if that is
your USB card reader).

You also did not mention if the card is formatting using FAT32, exFAT,
or NTFS. Generally NTFS results in faster transfer than FAT32, plus
NTFS doesn't have the 4GB max file size limit of FAT32.

https://www.flexense.com/fat32_exfat...omparison.html

exFAT beats NTFS for some tests; however, exFAT has no journaling to
help protect files from corruption.

You could go into Device Manager to look at the properties of the USB
drive when it is plugged in and recognized. Check the Policies tab to
see if Quick Removal is enabled (for safer handling of the drive) or if
Better Performance is selected (which means you *must* safely eject the
drive before physically disconnecting it; else, some data in the write
cache won't get written to the drive, so you lose data and possibly
corrupt the files). You never mentioned if you were safely ejecting
(which is just a disconnect, not physical ejection) the card before
removing it from the USB card reader or the USB card reader from your
PC's USB port.

You said you have a SIIG USB card reader. You did not mention if you
are using that on a PC or with your Moto X4 phone (don't know if it
could be used that way on the phone). I've not looked into USB transfer
speeds on PCs versus smartphones. My cursory reading of some online
articles has USB ports on smartphones being a lot slower than USB ports
(of the same version, like 2.0 or 3.0 for both) on PCs. OTG (on-the-go)
seems even slower. I only used an OTG drive once with my smartphone and
found it slow (until it died and Samsung replaced it afterwhich I didn't
rely on it anymore). Some phones have USB 3.0 ports while some still
only have USB 2.0. I have the LG V20 whose specs say USB 2.0 but
benchmarking by others shows it has USB 3.0