Rabbit
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Post by Rabbit on Jul 13, 2016 7:23:55 GMT
It seems that all SD cards aren't all the same.
I have quite a lot of them for my Fiio daps ranging from 32 to 128gb. (And cameras) Never had problems with the 32gb but my first 128gb seemed less secure and tended to crash etc., even after a formatting. I gave up on it and got another make which seemed fine.
Yesterday, I phoned Amazon support because I was getting an error every time I tried to download a film onto a Kindle Fire. It worked, then it didn't, then it did .......
In the end, it wouldn't save anything.
Amazon support did a remote support thing, where they take control of the Fire and a technician had a look. He set it all up again and off it went, saving files. So for all intents and purposes, the problem was fixed, although he wasn't sure what it was really.
An hour later, it stopped again. (I'm downloading films for my holiday flight)
I went into settings and set it so that it was saving films to the Fire and it worked again. Back to the card and it stopped.
So, the whole problem was caused by a 64gb card which has been working for a year and suddenly decided it wasn't going on any more. I tried to reformat it in my computer and that showed there was some kind of problem. The computer was unable to access or reformat the card.
So I didn't use it again, I broke the back off before chucking it away. What surprised me was just how easy it was to break the back away. Suggests that maybe they are prone to flexing? So when pulling them out of a storage box, it seems that we might need to be careful not to bend them?
It did teach me a lesson ..... don't trust sd micro cards; even if they've been working perfectly for a year. Back ups are crucial.
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Post by marveltone on Jul 13, 2016 12:35:00 GMT
I've noticed the reviews on micro SD cards are all over the board. It does seem that the higher priced models (reputable brand names) tend to get slightly better overall reviews, as do the smaller capacity, but that's no guarantee, either. I personally have yet to have a problem, but it's just a matter of time. In the end, I think you're right about keeping a backup.
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Rabbit
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Post by Rabbit on Jul 13, 2016 14:53:27 GMT
It surprised me how easily it snapped when I destroyed it, so durability could be another issue.
I had no warning of anything going wrong. It just stopped storing files in mid download!!
These aren't particularly cheap ones either!!
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Post by Mr Trev on Jul 14, 2016 21:46:15 GMT
I've see people who'll always swear by Sandisk and others that curse the things. So far I haven't had any problems with mine (kingston, patriot) so I really think its mostly a lottery. Strangely enough, Ive read more complaints about the full sized SD cards.
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garyc
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Post by garyc on Aug 11, 2016 14:29:43 GMT
...<omitted> It did teach me a lesson ..... don't trust sd micro cards; even if they've been working perfectly for a year. Back ups are crucial. Wise words. NAND flash memory is inherently unreliable - the memory cell arrays have to be managed by sophisticated controllers which employ quite heavy error protection and correction (a different league to, say, ECC DRAM where simple parity provides single bit error detection; by contrast, ECC for flash has to cope with up to several 10s of errors per page - 2KBytes and up). The biggest contribution to errors in flash are retention errors - think of the flash cell like a leaky bucket, it's filled up with charge when programmed (cell written to) then gradually loses charge over time. Originally the buckets represented one bit (SLC, Single Level Cell NAND) - charge present, bucket half full or more, equivalent to a 0, charge not present, bucket half full or less, (when a cell is erased, the bucket become notionally empty) a 1. Once a full bucket had leaked away to less than half full, a 0 would be confused as a 1 - a read error. Then to increase the density, the quantity of water represented 2 bits (so-called Multi-Level Cell MLC NAND). Now, empty == 11, third full == 10, two thirds full == 00, full == 01 . Now you only have to leak one sixth and the level moves into the lower adjacent two bit representation - again, one bit error (the 2 bit states are Gray coded so only one bit changes from state to state). TLC (Three level cell) NAND increases the bit density still further, making leakage errors even more common. All this means that anything I write to SD cards I either have a backup copy elsewhere (in the case of music, I copy from a RAID 1 equipped server) or I immediately copy to a backup (photographs get transferred ASAP to the server, I don't leave them hanging around on flash for long). SSDs have more sophisticated controllers than the kinds used in USB sticks, SD cards and eMMC flash in mobiles/tablets, but the same basic principle of NAND flash applies - the charge will leak unless the data is refreshed/re-written, so the longer you leave data in flash, the more likely there will be errors when you come to read it again. There are really only 4 main players in NAND flash manufacture - Samsung, Toshiba/Sandisk (they have a JV), Intel/Micron and Hynix. Any other brands will use flash from one of those companies. Personally, I only ever buy Sandisk or Samsung, as NAND bought by a 3rd party from the big 4 may well have been purchased on the open market and may not be the best quality. Right now, 64GB Samsung cards retail at £12.99, 128GB are more like £34.99, so I have never bought 128GB (and will not unless it becomes markedly cheaper per GB for the higher density) as I don't feel it's worth the risk given the increasing liklihood of uncorrectable errors with TLC (and now 3D NAND) that these bigger capacity cards use. SSD controllers are now employing LDPC for error correction, I'm not sure about SD card controllers, but they may still be using BCH due to the differing operating parameters of SD Cards vs. SSDs (fewer r/w and erase cycles with SD cards).
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Rabbit
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Post by Rabbit on Aug 11, 2016 15:11:04 GMT
You've made me even more nervous now Gary. Although these cards are tiny with big memories, I am very aware that stuff could be gone in a flash.
Before I went on holiday, I backed all my cards up to computer. Trouble is, it's a lot to store.
2x 128gb 4x 64gb 4x 32gb
And all that music is sitting here with me in Florida!!!
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garyc
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Post by garyc on Aug 11, 2016 15:57:29 GMT
... And all that music is sitting here with me in Florida!!! Florida you say... pretty hot there isn't it? Don't want to worry you further, but: "Increased temperature exponentially increases retention loss" (from Data Retention in MLC NAND Flash Memory ). Best to wrap those cards in a plastic bag and keep them in the fridge, or turn up the aircon. :-)
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Rabbit
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Post by Rabbit on Aug 11, 2016 20:37:11 GMT
It's baking here!! Just had to come home because my daughter was losing the ability to even stand in the sun! My wife has a heat rash. I'm fine since I have a pretty good tan from sitting in the garden at home. So I have all of my cards in my bedroom safe so it's fairly cool. I love the tropical heat but the others suffer more than I do.
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Rabbit
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Post by Rabbit on Sept 18, 2016 9:04:22 GMT
I've found a slight problem with 128gb cards on Fiio players.
Mine are class 10 and play MP3 fine. However, I have been getting 'stuttering' on my x3 with some files. Stopping the player and starting again did the same but in a different place. So it wasn't bad files, which is annoying because I stupidly deleted some other files a few months back that were stuttering, thinking that there was a problem. Luckily, I had backups.
Putting the cards that stuttered into my X5 revealed stuttering as well, but again, in a different place.
Then I took a closer look and found that in all cases, the stuttering files were hi res FLAC 24/192.
So I copied a stuttering file from that sd card to another, lower capacity card. The file played fine.
It seems that although the Fiios are compatible with 128gb cards, they do have problems with hi res stuff, but not on lower capacity cards.
The solution for me was to just transfer everything to 64gb cards and now everything plays fine.
So watch out if you buy 128gb cards. They work in most cases, until you get to hi res FLAC!!
The cards themselves are all Sandisk Ultras, all bought at the same time in different capacities. I bought 2 X 128gb, plus 4 X 64gb. I have another 3x 64gb on the way today to empty everything from my computer. I also have 4x64gb full of hi res and DSD files which play perfectly.
So if anyone wants two 128gb cards cheap, just say. They work fine for MP3 but be careful with hi res. If you don't use hi res, then they're absolutely fine. Very annoying for me though because high capacity cards would have been useful for hi res files!!
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solderdude
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Post by solderdude on Sept 18, 2016 11:08:21 GMT
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Rabbit
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Post by Rabbit on Sept 18, 2016 11:18:39 GMT
Not sure I have fakes Frans. The data loads on and off and the Fiio sees everything. With fakes, they normally don't have the capacity to take the amount that they say. I've tried some fakes in the past.
It's almost like there's a blockage and the card transfers data too slowly. (In which case that could be a fake but showing a different symptom)
They came from Amazon. Maybe the 'class 10' branding is wrong?
Anyway, I've sorted out 256gb of data now onto smaller cards!!!
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Post by tracestar on Sept 18, 2016 12:27:06 GMT
I've found a slight problem with 128gb cards on Fiio players. Mine are class 10 and play MP3 fine. However, I have been getting 'stuttering' on my x3 with some files. Stopping the player and starting again did the same but in a different place. So it wasn't bad files, which is annoying because I stupidly deleted some other files a few months back that were stuttering, thinking that there was a problem. Luckily, I had backups. Putting the cards that stuttered into my X5 revealed stuttering as well, but again, in a different place. Then I took a closer look and found that in all cases, the stuttering files were hi res FLAC 24/192. So I copied a stuttering file from that sd card to another, lower capacity card. The file played fine. It seems that although the Fiios are compatible with 128gb cards, they do have problems with hi res stuff, but not on lower capacity cards. The solution for me was to just transfer everything to 64gb cards and now everything plays fine. So watch out if you buy 128gb cards. They work in most cases, until you get to hi res FLAC!! The cards themselves are all Sandisk Ultras, all bought at the same time in different capacities. I bought 2 X 128gb, plus 4 X 64gb. I have another 3x 64gb on the way today to empty everything from my computer. I also have 4x64gb full of hi res and DSD files which play perfectly. So if anyone wants two 128gb cards cheap, just say. They work fine for MP3 but be careful with hi res. If you don't use hi res, then they're absolutely fine. Very annoying for me though because high capacity cards would have been useful for hi res files!! I had stuttering on and off playing high res FLAC files on my iBasso DX50 when I got a 128gb Sandisk microsd. It's always at a different part when I stop and start playback. Solved it by reformatting it to fat32. Didn't have any problems when I used 32gb and 64gb microsd. No idea whether this trick would help you or not.
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Rabbit
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Post by Rabbit on Sept 18, 2016 13:07:03 GMT
Aha. Same exact problem. I'll have a look, but I'm not sure Windows 10 allows me to do that .....
Thanks for that. I'll give it a go.
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Rabbit
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Post by Rabbit on Sept 18, 2016 13:12:20 GMT
I just checked and mine's just set on default. Exfat with default allocation size. Should I set the allocation size to 32?
Oh no ... I just looked up 'default' and for that card size, it is 32 already on default.
I'll format a card and move my music files back from the computer to see if that's the cure. When I got the cards, I did a 'quick format' not the long winded full one.
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Post by tracestar on Sept 18, 2016 15:18:30 GMT
I just checked and mine's just set on default. Exfat with default allocation size. Should I set the allocation size to 32? Oh no ... I just looked up 'default' and for that card size, it is 32 already on default. I'll format a card and move my music files back from the computer to see if that's the cure. When I got the cards, I did a 'quick format' not the long winded full one. Changing the default partition size wouldn't help since its the exfat format that's the culprit. Unfortunately, you can't format it to fat32 in Windows 10 if the usb / microsd card is bigger than 32gb. There are tools to format it to fat32 for Windows though I didn't use it. I have a Linux desktop too so i just reformatted in Linux. Right now I'm travelling so I don't have access to my PC and won't be able to confirm what tools would work for Win 10. I'll drop in here again once I'm home.
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