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Newbie
Posts: 2
Registered: ‎02-16-2013

Re: 32GB Class 10 Micro SD card - unexpectedly removed in Android

Pointless for me to return it to dealer and asking for a new unit if this is going to be a persistent problem. I will end up requesting for RMA every 3 motnhs or so, it this what Sandisk wants?

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Newbie
Posts: 2
Registered: ‎04-30-2013

Re: 32GB Class 10 Micro SD card - unexpectedly removed in Android

[ Edited ]

Guys, it's not the card - it's the Class 10 rating.  You want a Class 2 or Class 4, but nothing higher than 4.  You don't want high read/write speeds, you want high Random Access response times.

 

Class 10 = High Write/Read, Very Low Random Access response times.

Class 2 = Low Read/Write, Very High Random Access response times.

 

It's a give or take, but not both.  You don't want high read/write speeds on sdcards, they are all very slow anyways.

 

Class 10 cards are for digital cameras that has 10 to 20 MB of data to write as fast as it can.  They are not for mobile devices.

 

All mobile devices (Windows Mobile, Windows Phone 7 (my personal hacks), multiple Androids, etc) all have built-in "timeouts" for request queues when reading/writing to a device (e.g. sdcard).  This is because mobile devices are synchronous, with only a single device able to read or write bits at a time.  Eveyrthing goes into a "queue" waiting to read/write, and everything has a timeout in that queue.

 

I had all sorts of issues with Windows Mobile and Android phones in the past, but they still worked mostly.  Until I got my Windows Phone 7 two years ago and immediately opened my HTC Arrive to replace the 16 GB Class 2 card with a 32 GB Class 10.  Immediate crashes, reboots, etc followed.  Returned the card, got a new one, same thing.  

 

As it turns out, a local Microsoft rep told me the secret: Windows Phone 7 operating system has "stricter timeouts" for the storage queue (read/writing).  They require extremely low Random Access times to shave 50% or more "milliseconds" from the response of WP7's GUI.  That's what makes WP7 so "snappy" with instant touches.

 

That made perfect sense!  I since purchased a SanDisk Class 2, stuck it into my HTC Arrive, and had zero problems.  The device was rock solid, and very very fast.  I have since purchased Class 2 and Class 4.

 

The problems that Microsoft had with the first batches of WP7 devices was that no one could produce an SDCard with a low-enough response times.  SanDisk was sold out of the Class 2/4 16GB sdcard cards for 3 months, which delayed a large amount of WP7 phones from being shipped.

 

 

Just want to reiterrate that I have since purchase 6 or 7 Class 2 and 4 cards rangomg from 16 GB to 64 GB, and they have all worked flawlessly for my devices and all friends' devices that asked me which card to get, including on friend with a Galaxy Note 2 and a 32GB Class 2 card.

Newbie
Posts: 1
Registered: ‎04-30-2013

Re: 32GB Class 10 Micro SD card - unexpectedly removed in Android

Hi eduncan911and all,

 

This makes sense and I'am happy to have found an evplanation. I have bought my 32G micro sdhc card in mid Decembre 2012 and about 2 weeks ago it started with the problems about 'unexpected removed by android'. It ended up in drainig the battery of my galaxy s2 drastically until removing the card.

 

Altough I know how to go on further now, I'm unhappy with this all. Have you ever seen the promotion and the package of the product? Sandisc literally suggest to use it espexially with Android devices. Just look at

http://www.nextgen-zone.com/assets/images/ultra_micro_sdhc_class-10_16gb_750-x-480.jpg.

 

I feel dissapointed because this doesn't match at all with the technical workaround described in your post. Or your words are pure nonsense (I don't think so) or Sandisc wants to sell inadequate products for the promotion and description delivered for the product..

 

Looking around same forums (I did researches for several hours in 4 different languages) I see many users posting the same problem. This topic does tear the reputation od Sandisc.

 

@ Sandisc

Is there any proactive way to deal this problem from your side or will you just wait for +- 80 % of the users claiming guarantee and never buy your products again? We want a product that fits our need (as promised in promotion)  and a hassle-free change of product.

Newbie
Posts: 2
Registered: ‎04-30-2013

Re: 32GB Class 10 Micro SD card - unexpectedly removed in Android

Older phones, like the HTC Hero I have (Android 2.1), didn't have an issue with Class 10.  Only newer phones seem to have this problem (just a guess, but the faster the hardware/OS, the more it holds the timeouts to their word?).  hehe.

 

Newbie
Posts: 3
Registered: ‎05-02-2013

Re: 32GB Class 10 Micro SD card - unexpectedly removed in Android

Hi, I had this same issue with a Class 10 SanDisk Ultra 32GB microSD card, I bought it on October 2012 and used it happily in my Samsung Galaxy Note until February 2013 when I started facing this same problem, repeated messages that I had extracted the card until now when it is completely unreadable by either phone or computer.

 

I called SanDisk today and they said they would ship a replacement card, and denied that this is a specific problem with this card, said that millions of people use SanDisk cards successfully and only those who have problems write in forums for certain problems. Now I must take a picture of the card and send it to them, then I must destroy the card and they ship a replacement.

 

I hope this is not a general Class 10 problem... your explanation makes sense except for one point: why people (myself included) get to use the card happily for 3-4 months (approx) until it starts having problems? I had absolutely no problems before the time when I started getting the "card removed" messages. I don't know about WP7, my experience is with Android 4.0.4 in my Galaxy Note 1 phone. I hope the replacement works.

 

Best and thanks for the info.

Newbie
Posts: 1
Registered: ‎05-10-2013

Re: 32GB Class 10 Micro SD card - unexpectedly removed in Android

I had this same issue with a Class 10 SanDisk Ultra 32GB microSD card on my Galaxy S3.

my card seem no error after check by windows 7 utility but offen unexpectedly removed in Android.

 

I guess the problem issue because android has updated the os with patch, that why people (myself included) get to use the card happily for 3-4 months (approx) until it starts having problems.

 

 

i need the action from sandisk to fix this, it drain my battery to emty so fast.

Newbie
Posts: 1
Registered: ‎05-13-2013

Re: 32GB Class 10 Micro SD card - unexpectedly removed in Android

This is happening on the Galaxy S4 as well. It's unbelieveable how nowadays companies can sell worthless products that don't work just to get the income. There is absolutely no recourse because the data on the card is irreplaceable. I was using the Class 10 SDHC Micro 32GB in my phone for 5 days. All of a sudden, it starts with the "card unexpectedly removed" error. Then it would unmount and mount continuously. I figured I'd at least get the data off by putting the card in my laptop. Nope. All I got was a "no drive" error, so everything's gone.

 

SanDisk is a huge company so like most large companies today, they probably couldn't care less, but I really hope they lose something as important to them as everyone using their products is. 

SanDisk Guru
Posts: 4,191
Registered: ‎07-18-2007

Re: 32GB Class 10 Micro SD card - unexpectedly removed in Android

it is strange that the only reports of this issue are with samsung phones. i ahve not seen anyone with any other manufacturer Android phones ever reporting this issue. that said if the card is not mounting even in the computer it will need to be replaced. Probably best to give sandisk support a ring 866-sandisk. 

Newbie
Posts: 3
Registered: ‎05-02-2013

Re: 32GB Class 10 Micro SD card - unexpectedly removed in Android

Yes, and it's strange the way they answer, as if denying that anything is going wrong. When I called Sandisk they made an effort to make me understand that this is not a widespread problem, just some people with problems that complain in a forum. There is clearly a problem with the Ultra 32g card mostly in Samsung phones, people, talk with Samsung and fix it! We are losing tons of precious info!
Newbie
Posts: 4
Registered: ‎05-14-2013

Re: 32GB Class 10 Micro SD card - unexpectedly removed in Android