Database Users

SD read/write speed causing lag on my HD2 but...

So I downloaded this app call H2testw.exe to test for legit sdcards but it also tells the read/write speed as well. I am testing my 8gb and 1gb cards. I set it to write a 300 mb files to the card and verify it.
Info about Android running on the two cards:
8gb = lags coming out of sleep, touch screen freezes, write~7.5 mb/s, read~12mb/s
1gb = no lags, no touch screen, write~4.3mb, read~13mb/s
I'm confused. The read speed is almost the same yet the 1gb microsd is more responsive running MDJ android compared to the 8gb microsd. Any thought?
UPDATE: Maybe this is what's causing the problem. Stolen from Engadget.
What we've learned from our tipsters and from documents culled from Microsoft, Samsung, and others is that the big issue is random access performance -- a figure that isn't taken into account in a card's class rating. Ironically, Microsoft discovered in its testing that cards with higher class ratings actually performed worse on Windows Phone 7 because the tweaks card manufacturers make to achieve high sequential throughput can actually hurt random access times. There's some rocket science involved here, but basically, it's a tradeoff and a bit of a gamble -- if a manufacturer tunes a card for a high class rating, it takes more time to access the first byte at a new location on the card because it's optimizing access for that area of memory, but once it does that, it can blast sequential bytes at very high speed. If you've got a lot of small reads or writes you need to make to different files at different locations in the card's memory, though, you really start to suffer. Cards with lower class ratings tend to spend less time optimizing sequential access prior to the first read / write operation, so it can move around the card (that is, access it randomly) much faster.
Click to expand...
Click to collapse
Source:
http://www.engadget.com/2010/11/17/windows-phone-7s-microsd-mess-the-full-story-and-how-nokia-ca/

They are probably different classes, plus it naturally takes longer with a bigger card because there's more files and more space to read and write
Sent from my HD2 Nexus One using XDA App

I get screen freezes with 8gb and up but rarely with new builds, haven't tried a card higher than class 6
Also I'm on radio 2.15
Sent from my HD2 Nexus One using XDA App

Oddly enough, I have two 8gb cards, one class 4 the other class 6, and they hiccup more than my 16gb class 2.
Now that is weird.

I'm lost myself...I'm thinking off just getting me a 4gb card and hope for the best...

I heard the 16gb class 10 is perfect but it still cost to much for nand to be around the corner
Sent from my HD2 Nexus One using XDA App

16 gb class 10 no lag cost me over 100 pounds tho
Sent from my HTC Desire using XDA App

Cheapest 16GB - lags from time to time :/
Maybe defragmentation may help?

tomus said:
Cheapest 16GB - lags from time to time :/
Maybe defragmentation may help?
Click to expand...
Click to collapse
Defrag wont help...scan for errors...try to have only the android folder and see if it makes a different ..

Btw, guys...
all sd cards are not created equal. all sd cards of the same CLASS are not created equal.
Check out the ongoing drama with win7 phones with SD slots....
class measures throughput, what affects the SOD and related issues is random access speed, not throughput so much.

It's just my 2 cents, but I've tested Class 2, 4, and 6 MicroSDHC cards and found very little noticeable difference once Android is fully booted up and running on the HD2. Moreover, none of the cards create screen freezes or SOD issues or high battery drain problems here. That said, I have noticed that the actual boot time and file transfer speed (from the PC to the card) can be faster on average with quality higher class rated cards of the same size. Also, I've found that the larger the card size, the longer the android boot time, no matter the class. Guess that makes sense, as the system need to read more sectors with larger size cards. Please note that I've only tested Sandisk, Toshiba, TopRam and Samsung cards to date. What's kind of strange is that the Class 2 16 & 32GB Sandisk cards run just as well or slightly better for some reason than some of my higher class rated cards. Go figure...
As far as issues go, I recommend only using quality brand name cards, no ebay fakes or cheap no name brands. Also, I've had great luck formatting all my cards with SD Formatter v2.0 and v3.0, using the quick format mode with the standard 32kb cluster size.
Best to all,
R

rhacy said:
It's just my 2 cents, but I've tested Class 2, 4, and 6 MicroSDHC cards and found very little noticeable difference once Android is fully booted up and running on the HD2. Moreover, none of the cards create screen freezes or SOD issues or high battery drain problems here. That said, I have noticed that the actual boot time and file transfer speed (from the PC to the card) can be faster on average with quality higher class rated cards of the same size. Also, I've found that the larger the card size, the longer the android boot time, no matter the class. Guess that makes sense, as the system need to read more sectors with larger size cards. Please note that I've only tested Sandisk, Toshiba, TopRam and Samsung cards to date. What's kind of strange is that the Class 2 16 & 32GB Sandisk cards run just as well or slightly better for some reason than some of my higher class rated cards. Go figure...
As far as issues go, I recommend only using quality brand name cards, no ebay fakes or cheap no name brands. Also, I've had great luck formatting all my cards with SD Formatter v2.0 and v3.0, using the quick format mode with the standard 32kb cluster size.
Best to all,
R
Click to expand...
Click to collapse
Great info here. I think I will just order me a new card from a reputable brand. Maybe my card is just getting old. Maybe a 16gb from Amazon will do. They aren't too expensive nowaday. ~$26.

Does the Radio version effects the lag of the sd card? Or the kernel?

distruct said:
Does the Radio version effects the lag of the sd card? Or the kernel?
Click to expand...
Click to collapse
No, not on the sd but radio does effect how the build will run, your phone calls, your battery.

Could this be the reason why class don't matter on hd2 android? I mean even some class 4 & 6 have lag and sod problem. I pulled this bit from engadget. It's an article on wp7 and memory card issues.
What we've learned from our tipsters and from documents culled from Microsoft, Samsung, and others is that the big issue is random access performance -- a figure that isn't taken into account in a card's class rating. Ironically, Microsoft discovered in its testing that cards with higher class ratings actually performed worse on Windows Phone 7 because the tweaks card manufacturers make to achieve high sequential throughput can actually hurt random access times. There's some rocket science involved here, but basically, it's a tradeoff and a bit of a gamble -- if a manufacturer tunes a card for a high class rating, it takes more time to access the first byte at a new location on the card because it's optimizing access for that area of memory, but once it does that, it can blast sequential bytes at very high speed. If you've got a lot of small reads or writes you need to make to different files at different locations in the card's memory, though, you really start to suffer. Cards with lower class ratings tend to spend less time optimizing sequential access prior to the first read / write operation, so it can move around the card (that is, access it randomly) much faster.
Click to expand...
Click to collapse
Source:
http://www.engadget.com/2010/11/17/windows-phone-7s-microsd-mess-the-full-story-and-how-nokia-ca/

azzzz said:
Could this be the reason why class don't matter on hd2 android? I mean even some class 4 & 6 have lag and sod problem. I pulled this bit from engadget. It's an article on wp7 and memory card issues.
Source:
http://www.engadget.com/2010/11/17/windows-phone-7s-microsd-mess-the-full-story-and-how-nokia-ca/
Click to expand...
Click to collapse
Obviously.
Been saying this for a while, myself - I have experimented, and I get SOD every time with my 16gb class 6 card, but rarely with my class 2 8gb, and never ever (and, tbh, better responsiveness overall) with my 2gb NON-HC card

enneract said:
Obviously.
Been saying this for a while, myself - I have experimented, and I get SOD every time with my 16gb class 6 card, but rarely with my class 2 8gb, and never ever (and, tbh, better responsiveness overall) with my 2gb NON-HC card
Click to expand...
Click to collapse
I hope so...my class 2 16gb will be here in a couple of days...i hope it's faster than my current 8gb class 4....
Update: my 16gb class 2 sandisk is here. Things have improved alot. Wake up is faster now with less lag, market download speed is faster now (10kb vs 100kb). Hopefully system performance will be better...

[Q] SD Card Worth It?

I am going to pick one of these up, but before I did, had a quick question (anyone with a WP7 can answer)
Do you feel that 8gb is enough space? Or do you wish you had more? Should I get an SD Card?

Most definitely. I have loaded most of my music and a few videos and I already used over 6GB. That's pretty much all the stock phone has. Now, I have over 14GB still left. Might put some movies on it.

My only disappointment in the focus is the 8GB stock NAND. For a $199 on contract device, 16GB really should be the minimum, especially considering a few other WP7 phones, to say nothing of Android phones and the iPhone, all start at $199 with 16GB.
That said, adding the SD card isn't that big a deal as long as you do it before you've filled the device up. For some reason there seems to be no ability to do a full backup of the phone by any means I've been able to find.

The problem with the SD Cards is that there's intense confusion/miscommunication about which cards work well. Just because it works with 6GB doesn't mean anything. What seems to happen is once you get to 8GB filled, the phone's performance takes a nose-dive, sometimes leading to losing all data.

"Enough space" depends on you, not us. I have an iPhone, iPad and iPod, all 16GB units, each with some 14GB or so of music & apps on them so it the first thing I did when I brought the Focus home was slap an 8GB card in there, format it and load it up. I have maybe 2GB free and it's worked without a single glitch for the past two weeks. For reference, mine is a Sandisk class 2. People seem to have problems with cards other than Sandisk and other than class 2 and I noticed absolutely no performance problems so if you're going to try it, try that and keep the receipt in case you need to return or swap it should something go sour.

Enough Space?
I agree with Mark, whether there is enough space or not really depends on what your usage requirements are.
I had a 32GB Zune and when I bought my Samsung Focus the Zune had over 20GB of data on it. So for me adding and 32GB SD card to the Focus was not only a desire but a very strong selling point for the Phone.
And yes, I am seeing a few issues with the Sandisk Card that is in it. Currently they are not enough to make me yank the Card because I (again) bought the device to specifically be a convergence device for myself and I am at heart a tester and tinkerer so figuring how exactly how WP7 works.doesn't work with an SD Card and the statement that MS and Samsung are working on a fix is enough for me right now.
Smaller Sized Cards seem to be more reliable than larger cards (not to mention less expensive) but that appears to anecdotal evidence as well. My 32GB Sandisk only causes freezes and resets when on Battery for example and I've not had anyone else confirm if they are seeing the same.
Not great answers but, hey, this is the fun of learning as we go along...
- MEK

FishFaceMcGee said:
The problem with the SD Cards is that there's intense confusion/miscommunication about which cards work well. Just because it works with 6GB doesn't mean anything. What seems to happen is once you get to 8GB filled, the phone's performance takes a nose-dive, sometimes leading to losing all data.
Click to expand...
Click to collapse
I have more than 11GB on my Focus with no issues at all. No slow-downs, no hiccups, no data loss period. I am currently using a PNY 16GB Class 2 card. I previously had a Centon 8GB Class 6 card with the same results.
If you read the thread on MicroSD cards, it seems there are some cards that have been working pretty much flawlessly. Both of the cards I mentioned have worked perfectly for me. I gave the 8GB to a friend and he is using it in his Focus as well.

For me, to really make a portable phone/audio/video device be best for me it would need at least 150GB of storage... and a few TB if i wanted to listen to music lossless and a few movies.

MKohlman said:
I agree with Mark, whether there is enough space or not really depends on what your usage requirements are.
I had a 32GB Zune and when I bought my Samsung Focus the Zune had over 20GB of data on it. So for me adding and 32GB SD card to the Focus was not only a desire but a very strong selling point for the Phone.
And yes, I am seeing a few issues with the Sandisk Card that is in it. Currently they are not enough to make me yank the Card because I (again) bought the device to specifically be a convergence device for myself and I am at heart a tester and tinkerer so figuring how exactly how WP7 works.doesn't work with an SD Card and the statement that MS and Samsung are working on a fix is enough for me right now.
Smaller Sized Cards seem to be more reliable than larger cards (not to mention less expensive) but that appears to anecdotal evidence as well. My 32GB Sandisk only causes freezes and resets when on Battery for example and I've not had anyone else confirm if they are seeing the same.
Not great answers but, hey, this is the fun of learning as we go along...
- MEK
Click to expand...
Click to collapse
You know, I was thinking about this the other day...the phone has 8GB of internal memory and if you put in an SD card it stripes data across it and the internal memory. If the card is 8GB or smaller that's fine but what happens if the SD card is larger than internal memory? It doesn't stripe the first 8GB and set the rest up as another partition and it does appear to use but it can't be striped. Now you've mentioned that smaller sized cards work better and my 8GB card works perfectly. I wonder if the file system's attempt to work with a larger card is inherently unstable? I know that if you put two different sized drives in a Windows box and stripe across them you will only end up with double the size of the smallest drive, not the actual sum of the two. Might be an interesting poll...indicate the size of your SD card and if the phone has been 100% stable since inserting it.

markgamber said:
You know, I was thinking about this the other day...the phone has 8GB of internal memory and if you put in an SD card it stripes data across it and the internal memory. If the card is 8GB or smaller that's fine but what happens if the SD card is larger than internal memory? It doesn't stripe the first 8GB and set the rest up as another partition and it does appear to use but it can't be striped. Now you've mentioned that smaller sized cards work better and my 8GB card works perfectly. I wonder if the file system's attempt to work with a larger card is inherently unstable? I know that if you put two different sized drives in a Windows box and stripe across them you will only end up with double the size of the smallest drive, not the actual sum of the two. Might be an interesting poll...indicate the size of your SD card and if the phone has been 100% stable since inserting it.
Click to expand...
Click to collapse
I'm not totally convinced based on comments in blogs that the disks are "striped". I think a lot of people are saying this and maybe using the term out of context and everyone just keeps using it. Has Microsoft actually come out to say "WP7 performs RAID 0 configuration"? For a phone OS which was never intended to see anything other than a single drive, don't you think throwing a RAID controller in there just for kicks is a little absurd?
The other term is "span" and if I had money, I'd bet that the two disks were spanned as a single partition, as opposed to striping like RAID 0 does.
Despite all of that, I have tried a 16gb class 4 with more issues than I cared for and currently have an 8gb class 4 with negligible issues. Any card you get, I'd run on Vista/Windows 7 and test for ReadyBoost. That at least tests the card for random access speed, which is important. My 16gb failed readyboost and had lots of issues in my Focus, whereas the 8gb passed and the only issues I've seen with that one are issues that other people might have experienced on their own phones sans sd card.

hyperzulu said:
I'm not totally convinced based on comments in blogs that the disks are "striped". I think a lot of people are saying this and maybe using the term out of context and everyone just keeps using it. Has Microsoft actually come out to say "WP7 performs RAID 0 configuration"? For a phone OS which was never intended to see anything other than a single drive, don't you think throwing a RAID controller in there just for kicks is a little absurd?
The other term is "span" and if I had money, I'd bet that the two disks were spanned as a single partition, as opposed to striping like RAID 0 does.
Despite all of that, I have tried a 16gb class 4 with more issues than I cared for and currently have an 8gb class 4 with negligible issues. Any card you get, I'd run on Vista/Windows 7 and test for ReadyBoost. That at least tests the card for random access speed, which is important. My 16gb failed readyboost and had lots of issues in my Focus, whereas the 8gb passed and the only issues I've seen with that one are issues that other people might have experienced on their own phones sans sd card.
Click to expand...
Click to collapse
I've read both, striped and spanned...who knows. Considering how slow SD memory always was in old WinMo devices, I didn't think it absurd to stripe data to provide the same kind of speed boost you get when striping hard drives. Hard as it might be to believe, it may have just been that WinMo was slow. I hadn't thought of the readyboost test, that's a good idea. Readyboost is pretty picky.

[Q] MicroSD Suggestions

Do you use a MicroSD? What kind? I'm shopping for one and can use some suggestions... From cheap to expensive... Preferably cheap (;
16gb or 32gb
Class rating, I'm not sure. Are there any consideration for this on the tablet?
Ordering from NewEgg so if you have a link for one there, post'em.

Don't go too cheap. With stuff like this you do get what you pay for to some extent.
Sandisk, Patriot, Kingston, PNY, Sony etc are all brands I've had luck with. At present I've got a 16GB PNY. http://www.newegg.com/Product/Product.aspx?Item=N82E16820178378
I got it for a higher price a while back, but no problems here in my Gtablet, A500, PC or either of my 2 laptops, one of which runs Debian 6.0

I get mine from Amazon, since I get free 2 day shipping with Amazon Prime. Picked up a Sandisk for a little over $56.
http://www.amazon.com/gp/product/B003WGJYCY

Is there a difference between SD and SDHC? And what about class?

Heres what im looking at-
http://www.newegg.com/Product/Product.aspx?Item=N82E16820220547&Tpk=microsd
2x32gb for 80'ish which seems like a good deal to me considering 1 goes for near 70... or am i reading that wrong... wife could use one for her hand me down archos 101.

gammaRascal said:
Is there a difference between SD and SDHC? And what about class?
Click to expand...
Click to collapse
SD is limited to 2GB, SDHC was the newer standard, supporting up to 32GB. SDXC is the newest, but I don't think there is a micro form factor yet and I don't imagine our devices have SDXC controllers in them. I may boycott SDXC for using proprietary exFAT as the recommended filesystem too.
Class is a speed based thing. Class = minimum write speed in MB/s(technically a multiple of 8Mbps). So Class 2 = 2MB/s. Class 10 = 10MB/s. Write speeds. Keep in mind reads will be faster usually.

Awesome, thanks for that concise explanation.
Does the tablet have a maximum class rating? Will it bottleneck on class 10? I'm looking at the class 6 as a minimum.

Well, maybe class 4... I just want to store my music on it and have it as some extra storage. Class 4 should be fast enough, eh? I wont be moving apps to it - ill keep those on the primary storage. But for playing music, accessing pictures, class 4 seems like it would fast enough for that.
Thoughts?

Folks,
Also, I have been using SDHC's and microSDHCs for a while now and it
has been my experience that sometimes there a little incompatibilities.
Even good brands sometimes don't seem to work for some reason.
I'm saying, pick your best choice, but that doesn't GUARANTEE it
will work. Need a little good fortune also!!!
Rev

Okay, I'm ordering:
Kingston 16GB Micro SDHC Flash Card w/USB Reader Model MRG2+SDC4/16GB
$32.99
http://www.newegg.com/Product/Product.aspx?Item=N82E16820139195&cm_re=microsd-_-20-139-195-_-Product

I wouldn't pay any extra for anything beyond class 6 or so for a tablet. If a 10 was on special for a really good price maybe, or if you shared it with a camera that needed a class 10 maybe get one.
I suppose we could port hdparm or bonnie to our tabs and run it from adb shell or busybox and see if different class cards got different rates.

I got my SD card a few days ago - the one I linked to two posts up.
Plugged it in (has a usb sleeve) and moved a few songs onto it, put it in the tablet, started the tab, started Google Music and it saw them all. Shut down, moved about 8 gig of music onto the card, plugged it back into the tab, booted, launched Music, took a few seconds but it saw them all, played some and everything is golden.
I'll check in if I ever have any issues.
Thanks for the help folks!

I realize you already got your card, but figured I'd throw in one extra piece of info in the event that anyone stumbles upon this thread in a search at a later date.
You asked a question about class and an early poster provided some great info about what SD card classes mean. I think it's important to note that the class you need depends on the intended usage of the card. High speed cards (those with high class ratings) are most important for applications that require you to write large amounts of data in short amounts of time. The best example of this is photography. Rapidly taking high resolution images requires that a ton of data be written to a storage medium very quickly. As such, you'll see class ten cards in a lot of cameras.
If you intend to do things like store documents, music, etc. on the card - primarily for consumption - you don't need high speed.
One thing to note - if you write to the card a bunch (throw a few new hd movies on there every couple days) you will appreciate a better write speed. Also, picking up a higher speed card means that it can be used for a number of different applications (sharing with a camera for example). Given that there often is only a slight difference in price between a low speed and a higher speed it's usually a better deal to get a higher speed card (the flexibility and time savings are worth a few extra dollars).

Good info. Thanks for chiming in!

just a small FYI ...
with froyo ... SDcard IS SDcard & you can APP2SD or used what I have sworn by -->> MOD INSTALL LOCATION ( in phone forums )...etc
Now.. we have HONEYCOMB... and it partition a little differently. ( although I believed it's the manufacturers that have the final saying... based on the comparision between the Acer & the Asus )
the 2 read your physical SDcard like this:
Asus -->> REMOVABLE
Acer -->> EXT microSD
Your EXT SDcard is only good for storing data/medias ...etc ( currently apps cannot be install on the physical card.
your whole internal is actually partitioned into 2 areas
/ 1 small part for the OS/ROM ..etc
/ the LEFTOVER is actually read as THE SDcard !!!
use a file manager and explore the directories structure to see what I mean !!
so ... 2 future solutions:
1/ XDA DEVs will find a way to let us install to a preferred location. ( and they will !!... in due time )
2/ application developers just have to write their new programs to accommodate Honeycomb ..etc

Kingston 64Gb microSDXC card keeps getting dirty and corrupted

I'm fed up with this damn sd card. I use this microsd card with a sd adapter for my duo11 and it keeps getting dirty or corrupted. This is the second time it got dirty and a few days ago i lost almost 40gbs worth of stuff because of some corruption in one of the folders. It was impossible for me to recover any data from it and now i'm too scared to transfer any files into it.
Does this mean the card is faulty?
I tried reformatting it but it gets dirty out of nowhere. Its formatted to exfat right now and i don't know what format it was last time.
Am i the only one having this problem?
Should i just buy an sd card for my tablet instead of a micro sd card and use a sd adapter for it instead??

How old and heavily used is the card. They do have a VERY short lifetime. Formatting actually eats into the lifetime slightly. Defragging would even more (although I think windows is clever about not defragging flash storage normally). Basically there is a limited number of times am SD card can be written to, also a limit on reads but reading has an almost negligible impact compared to writing.
Chances are if the card has been well used for even 6 months or so then the card is simply dying, it may have a warranty on it.
If its a new card then it is faulty, take it back to the vendor and demand a refund.
An SD card won't fare much better than a MicroSD. Many SD cards just have the circuit from a microSD stuck in one end, the back half of them tends to be hollow. only advantage of full SD is that you can get a 128gb card with 256gb cards expected to be released soon (and 128gb MicroSD).
SD cards often use a technique called wear levelling. This essentially deliberately fragments your data to spread it across the card and prevent the same locations on the card getting repeatedly written to. This does actually work better the larger the card is as there are more locations available, but 64gb is already huge so is plenty for wear levelling. Boosts the lifetime of the card considerably. But it doesn't always work so well when the card is full.
I would get the card sorted out and replaced. And then try to limit how often you actually read and write into it. Don't run applications off of it for example.
The raspberry pi guys often have plenty of issues with SD cards and their short lives. Booting Linux off of the things has a tendancy to kill then young.

SixSixSevenSeven said:
How old and heavily used is the card. They do have a VERY short lifetime. Formatting actually eats into the lifetime slightly. Defragging would even more (although I think windows is clever about not defragging flash storage normally). Basically there is a limited number of times am SD card can be written to, also a limit on reads but reading has an almost negligible impact compared to writing.
Chances are if the card has been well used for even 6 months or so then the card is simply dying, it may have a warranty on it.
If its a new card then it is faulty, take it back to the vendor and demand a refund.
An SD card won't fare much better than a MicroSD. Many SD cards just have the circuit from a microSD stuck in one end, the back half of them tends to be hollow. only advantage of full SD is that you can get a 128gb card with 256gb cards expected to be released soon (and 128gb MicroSD).
SD cards often use a technique called wear levelling. This essentially deliberately fragments your data to spread it across the card and prevent the same locations on the card getting repeatedly written to. This does actually work better the larger the card is as there are more locations available, but 64gb is already huge so is plenty for wear levelling. Boosts the lifetime of the card considerably. But it doesn't always work so well when the card is full.
I would get the card sorted out and replaced. And then try to limit how often you actually read and write into it. Don't run applications off of it for example.
The raspberry pi guys often have plenty of issues with SD cards and their short lives. Booting Linux off of the things has a tendancy to kill then young.
Click to expand...
Click to collapse
Its only been 3months or so. God i thought they would last as long as my hard drive seeing how they last ok on a phone. So there isn't no way of increasing hard drive space without replacing the hard drive? I'm using a duo11 which uses a 128gb ssd which would cost a fortune to swap it for a bigger one =.="

In a phone the SD is barely ever written to. You might stick some music on it when you buy the phone and maybe once or twice a fortnight. Perhaps the odd photo too, but otherwise the SD is under-used in a phone.
On the duo your best off using the SSD most of the time and just using the SD as long term storage.
Give Kingston a call and see if they will issue a new card under warranty.

Even an extremely low-end piece-of-junk SD card from five years ago should have a minimum endurance of at least 5k writes, and that's a really, really terrible one (even cheap flashdrives have typically over 50k writes these days). To come even close to wearing out a mere 5k writes in 6 months though, you would need to write the entire capacity of the card (remember, wear leveling) more than 25 times every day. Although this is certainly technically possible, the odds of it happening are extremely low unless you were running a database server off of it (or something equally foolish). For more realistic numbers of the card endurance, there is almost no physical way to burn through the entire write lifetime of the chip in three months.
Also, the Flash storage used in SSDs and tablets (and phones, for that matter) is basically the same kind of NAND flash used in SD cards. It might be higher quality - a decent SSD typically has 100k - 500k write endurance these days, which will last for many years of continuous use - but it has the same limits. People just don't realize how generous those limits are. I have perfectly functional SD cards from 2005 or so. I don't have much use for a 1GB SD card any more, but I used that thing for ReadyBoost on my Vista beta laptop, and that's about as heavy of a practical use case on a home PC you're likely to get... and it still works fine.
With that said, it's entirely possible for the cards to be defective. Too many bad Flash cells, a defect in the controller chip that does the wear leveling and so forth, or a reasonable number of other things. There's a lot more to an SD card than a slab of NAND cells... and even those could have a defect that slipped past testing. Warranty replacement sounds about right.

Depends on where OP gets the SD card. If bought from, say, eBay and not from an authorized big-name dealer, high probability for a counterfeit or reject.

Some of the guys running raspberry pi servers have had lifetimes as short as a month from branded cards (and usually no problems getting them swapped). That said, you probably can't get any more usage out of an SD card then when it is being used as the boot device for a computer.

MicroSD Card - Which?

Hello,
It seems NST can be fussy with MicroSD cards so a thread to determine requirements would be fantastic:
1) MicroSD, MicroSDHC and MicroSDXC - Which are supported? Which are recommended?
2) Capacity - After rooting what reasonable size card is required (basic app installation and an 'average' library)?
3) Class rating. You might think bigger is better but I've read reports that class 10 are no good. Similarly, below what class rating is the performance impaired?
For my own part, I am interested so that I either use a card I have or buy one as necessary. I have a plain old 2GB MicroSD (not HC or XC, and therefore without class rating). I'd like to use this to save a bit of cash (and because I've got it here ready and waiting, otherwise unused) however I'd like to be sure that it will operate acceptably both in terms of capacity and performance.
Thank you!

I used my NST for a short while with an old 2GB card, and it worked. I upgraded to a 32GB SanDisk Ultra Class 10/UHS-I SDHC, because I use Aardict with offline copies of Wikipedia etc. (~16GB or so) and it wasn't really economic to buy anything smaller or slower new. However, I've run into problems with the SD card disappearing until after a reboot (even with latuk's kernel with the Class 10 timeout patch that I pointed out to him), and when it comes back, it sometimes comes back with a corrupt filesystem (presumably as a result of the unexpected logical disconnection). I'm putting this down to the Class 10 speed of the card, and I've ordered a replacement Samsung 32GB Class 6 SDHC which I expect to be able to test soon.

cowbutt said:
I used my NST for a short while with an old 2GB card, and it worked. I upgraded to a 32GB SanDisk Ultra Class 10/UHS-I SDHC, because I use Aardict with offline copies of Wikipedia etc. (~16GB or so) and it wasn't really economic to buy anything smaller or slower new. However, I've run into problems with the SD card disappearing until after a reboot (even with latuk's kernel with the Class 10 timeout patch that I pointed out to him), and when it comes back, it sometimes comes back with a corrupt filesystem (presumably as a result of the unexpected logical disconnection). I'm putting this down to the Class 10 speed of the card, and I've ordered a replacement Samsung 32GB Class 6 SDHC which I expect to be able to test soon.
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Thank you for the reply.
So;
1) Is 2GB enough for 'normal' usage - Stock apart from i) rooting, ii) Kindle App (and dictionary), iii) Launcher 8, iv) small collection of Kindle books (for future proof, let's say <100) and v) misc small apps (e.g., BBC News, BBC Weather)?
2) If Class 10 is to be avoided - Will there be any 'real life' speed difference between a SD and a Class 6 SDHC?
Thanks again!

Apps live in /data which is ~800MB of the Nook's built-in memory. Android 2.1 has no 'move to SD' option, so apps will only use the SD card for caches and offline data (e.g. like Aardict). epubs are usually a few hundred KB, so even if you only have 1GB free, that's still ~3500.
I don't think IO speeds are much of a factor when reading books on a Nook; the CPU and eInk display are probably far more relevant.

SD Card for me like most holds books which are tiny. I do use it to store titanium backup path. I have a few BnW Mangas on there. 2GB should be more than fine. If your buying a card then get a 8GB / 16GB / 32GB class 6 whatever is cheapest GB per £ or $
Class speeds have greatest affect on the write speed of the card. For my other less fussy devices I tend to use samsung class 10 32GB cards which are quite cheap at around £20. They seem just as reliable (or I should say as unreliable) as more expensive ones which have died on me.
I wish I had a cache of little crappy sdcards as I constant have to put disk images on them to flash an android device and it usually involved me backing up one of data sdcards and retask it.

Thanks for the help - I think I'll give the 2GB a try. I can always replace it if it is not up to task and it is not doing anything else, so...
For books (only use I'll have for it) it would seem capacity is a non-issue. As for speed - Well, it's not going to be up to Class 6 standard but I have my doubts that I'd even be able to tell... Especially after a numerous reports that in certain cases (small files) some higher class cards are actually outperformed by lower class cards. And, hey, after getting the guy so cheap the idea of another £20 on an SD card is not ideal. I'll report back if I encounter any problems. Thanks again!

LavaChild0809 said:
Thanks for the help - I think I'll give the 2GB a try. I can always replace it if it is not up to task and it is not doing anything else, so...
For books (only use I'll have for it) it would seem capacity is a non-issue. As for speed - Well, it's not going to be up to Class 6 standard but I have my doubts that I'd even be able to tell... Especially after a numerous reports that in certain cases (small files) some higher class cards are actually outperformed by lower class cards. And, hey, after getting the guy so cheap the idea of another £20 on an SD card is not ideal. I'll report back if I encounter any problems. Thanks again!
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Write speed is not issue when using as how often do you write the books etc to sdcard. I only mention it for if your spending money.
Trouble I small or low speed sdcards are still usually around £5 min so its does not make financial sense to buy them. Also beware buying cards on ebay or similar sites alot of fakes. If there a few pound how cares but if your spending more.
Got an old phone in drawer? Might have a 1GB card in it etc.