[bobsilver]

Hi all.
 
I have a Fiio X7 and have purchased a Sandisk 200gb sd card for it.  I have been using 128gb cards with my Fiio with no issues.  The problems I am running into is regular corruption of the 200gb card as IO am copying data to it (also bought a Samsung 256gb card and seeing similar issues).  What is happening is I am trying to copy my FLAC music from my NAS to my cards.  I have several USB card readers that I use.  First off I am seeing a max of 7-10mbs copy speeds to the cards.  I have a combo of USB 2 and 3 readers, each plugged into their respective USB 2 and 3 ports.  They are similar in performance surprisingly.
 
I am copying chunks of music in 25-40gb groups.  Takes and hour or 2 to copy that much.  (the 128 cards were similar).  After a day of copy I check the cards and low and behold have errors and need to run disk check.  Disk Check takes forever on these cards.  On the order of days.  In fact I have never waited for one to complete.  I have just reformatted the cards and started over.
 
At first I though I might have a bad card or reader.  I have multiples of each and have similar problems.  I have also tried the copy routine on another pc (I am using Win 10 Intel i5 based systems for this).  Again similar results.  I have multiple 128gb cards.  I have had little issues with them.  Copy data and they generally work fine.  On occasion they need a disk check but that happens quickly and all is good.  No issues with my Fiio.
 
So my questions are is any one else seeing these kinds of issues with these high capacity cards?
 
What are you using to copy your music with?  
 
I am really stumped at this point.  Really want to use these cards as the Fiio only has 1 sd card slot.  But at this point I am stumped.
 
Thanks,
 
bobsilver

 

[PleasantSounds]

How confident are you of the source you got them from?
 
From what you are describing sounds like they could be "doctored" by some dodgy operator.
There is a proceder going on where some operators buy in bulk 8MB cards for pennies and modify the firmware on them to report any capacity you wish. Unfortunately computers get fooled by that and "copy" files to their full reported capacity, while all that gets actually stored is only the directory entries.