Develop Bugs

Time for a new micro sd card

I'm buying a larger SD card in readiness for Froyo (and I need more room for music!).
I've already filled up the 4GB card that came with the phone. Is it simply a case of copying everything from the 4GB card onto a computer, inserting the new card and copying it all back? Or is there some funky protection scheme in some app data which will break everything?
Also, will Eclair be able to format the new card (it's 32GB)? I think Windows 7 only formats fat32 on smaller drives.
Any information or other peoples experiences would be welcome.

If you just have one 4Gb partition it is safe to copy all the files to the new one and it should work without problems (copy also the hidden files).
For the format, Windows 7 can format it. Not sure if fat32 or exFat, but it can format it for sure.

Remember to buy a class 6 sdcard.
it will be much faster.

Oby One said:
Remember to buy a class 6 sdcard.
it will be much faster.
Click to expand...
Click to collapse
Just wanted to jump in here to clarify this statement. Higher classes means faster write speeds. There are no difference in read speeds.
Therefore...
- Having a higher class card will not result in better performance in tasks like generating thumbnails when viewing photos in your Photo application.
- If your application is installed on your card, higher classes will not mean faster application performance. Again, read speeds are not affected.
- Having a higher class card will mean you will be able to transfer files from your PC to your card faster.
That being said, you should buy the highest class card you can afford. But you should prioritize capacity over speed.
Tip: Pass on class 2 cards. They may start choking when you use your device to record 720p video.

ohyeahar said:
Tip: Pass on class 2 cards. They may start choking when you use your device to record 720p video.
Click to expand...
Click to collapse
Zero problems with my Sandisk 16gb Class 2 card. It writes at a sustaining 7.5mb/s, so faster than Class 6 minimums anyway.
Regards,
Dave

Thanks for all the advice guys.
Regarding the class, it has to be class 2 - it's the only thing available in 32GB.
However, as ohyeahar said, it's only write speed. I don't think a 720p stream will be a problem given the benchmarks I've seen for the Sandisk 32GB card. It seems to be writing at 5-7Mb/s so well above the Class 2 minimum.

I'm also buying a new microSDHC card. Should I format it in NTFS or FAT32?

Laban said:
I'm also buying a new microSDHC card. Should I format it in NTFS or FAT32?
Click to expand...
Click to collapse
Correct me if I'm wrong but when I format it on my computer, my desire always tells me to do it again anyway on my phone that is
Sent from my HTC Desire using XDA App

lennshow66 said:
Correct me if I'm wrong but when I format it on my computer, my desire always tells me to do it again anyway on my phone that is
Sent from my HTC Desire using XDA App
Click to expand...
Click to collapse
Ah, of course! That must be the correct way of doing it. Thinking of buying the Sandisk Mobile Ultra 16GB or the Transcend Class 6 16GB or A-Data Class 6 16GB.
Any recommendations?

Where is everybody looking to get their memory cards from? I'm currently looking for the best deals and struggling to find any decent ones tbh

ohyeahar said:
Just wanted to jump in here to clarify this statement. Higher classes means faster write speeds. There are no difference in read speeds.
Therefore...
- Having a higher class card will not result in better performance in tasks like generating thumbnails when viewing photos in your Photo application.
- If your application is installed on your card, higher classes will not mean faster application performance. Again, read speeds are not affected.
Click to expand...
Click to collapse
Click to expand...
Click to collapse
I think you are not well informed. Higher class cards also offer higher read speeds and that is very important.
In my phone applications are also writing to card so having a higher class card makes all the difference. especially if you are using it with a swap partition.
I don't have the link to the benchmark right now but I will show you tomorrow the different read/write speeds in different class cards
Therefore...
- Having a higher class card will not result in better performance in tasks like generating thumbnails when viewing photos in your Photo application.
Click to expand...
Click to collapse
Yes it will
- If your application is installed on your card, higher classes will not mean faster application performance. Again, read speeds are not affected.
Click to expand...
Click to collapse
yes it will
later edit:
I don't remember exactly the values for read speads but from my tests they were something like this
cls2 15mb/sec
cls4 18mb/sec
cls6 21mb/sec
for me ...speed is everything so class 6 it's my choice

Oby One said:
I think you are not well informed. Higher class cards also offer higher read speeds and that is very important.
Click to expand...
Click to collapse
Sorry, but that just isn't the case!
The class of an SD card is purely the minimum sustained write speed that the card will achieve in a completely unfragmented state. It has *nothing* to do with read speeds.
Case to point, here are the benchmarks for two of my MicroSD cards:
16gb Sandisk Class 2
Sequential Read : 20.050 MB/s
Sequential Write : 7.415 MB/s
8gb Transcend Class 6
Sequential Read : 19.938 MB/s
Sequential Write : 15.020 MB/s
Note that the read speeds are almost identical, but the write speed of the class 6 is almost twice the amount. However, the write speed of both cards is well in excess of the class 6 minimums and given that there's far less writing going on than reading, the difference in write speed is practically negligible on the Desire.
Which card do I used in my Desire? The 16gb Class 2 and I experience absolutely no lag whatsoever using my phone, and I'm using Froyo Apps2SD.
Regards,
Dave

Laban said:
I'm also buying a new microSDHC card. Should I format it in NTFS or FAT32?
Click to expand...
Click to collapse
fat32
10 chars

Hmm, maybe because it's a newer generation class 2 card?
perhaps my tests were done with older generation cards that gave out lower speeds.
Now I am curios...I can't wait to get back home and find the tests file.

foxmeister said:
Sorry, but that just isn't the case!
The class of an SD card is purely the minimum sustained write speed that the card will achieve in a completely unfragmented state. It has *nothing* to do with read speeds.
Click to expand...
Click to collapse
Yep, Dave is absolutely right, it's purely minimum sustained write speed for that class. And as you can see, his Class 2 card actually exceeds the class 6 spec for writing and isn't far off from Class 8 performance.
Looking around the web, the 32GB class 2 card I bought has similar performance in the benchmarks I've seen to Dave's Class 2 card. Not only that, the benchmarks are done on a PC. I doubt the phone has the I/O bandwidth to actually hit numbers like those in any kind of sustained way.

ok, my bad.
There is a slight difference between different brands (regarding read speed) but not so big.
regarding write speed .... I think that only if you use your sdcard with a swap partition you will see big differences.

[Q] What files to move to Class 10 SD card

Im thinking about going to ext4 and got a Class10 SD card to make the change at the same time.
Are people re-partitioning, or growing/shrinking/moving their partitions for swap or cache - and/or moving them or specific apps to the SD card ? Seems like the class 10 SD card is about 2x as fast if numbers are to be believed, but I cant be sure.
I spent hours checking these forums and the net and just figured I'd post to see what you guys knew about this....thanks in advance for your help.

All class 10 means is that once the card fragments the minimum will be 10mb/sec...not that its 2x faster...
In reality a Class 2 can and usually does run as fast as a Class 10..but once both card begin to fragment, Class 2 will be over 2mb/sec and Class 10 will be over 10mb/sec..

gTen said:
All class 10 means is that once the card fragments the minimum will be 10mb/sec...not that its 2x faster...
In reality a Class 2 can and usually does run as fast as a Class 10..but once both card begin to fragment, Class 2 will be over 2mb/sec and Class 10 will be over 10mb/sec..
Click to expand...
Click to collapse
I run through (download/delete) files on my sdcard like crazy-- given your info, is it good practice to defragment it every once in a while?

I think on the evo forums i read that htc said that the evo only workks at class 4 speeds. Maybe you should shoot samsung an email and find out what the epic supports. In the interest of full disclosure, i have a faulty memory and i could have dreamed that. Im not sure.
Sent from my nook COLOR.

I was under the impression that fragmentation is irrelevant on flash media. I was also under the impression that de-fragmenting flash media is a bad thing because all it does is reduce the life-cycle of the media.

Dropping in a tiny bit of research.. funny analogy:
From: ssj3strife
from: http://forum.cyanogenmod.com/topic/2890-how-to-defrag-your-microsd-card/page__st__20
"While fragmentation is never ideal, there are some scenarios where its effects are detrimental and significant, and there are other scenarios where its effects are negligible. Flash media is the latter.
A bad analogy for this - I wish I could come up with a better one - would be if you brought a harpoon gun with you when you visited the local swimming pool, because you were worried about sharks. It is true that if you were in the ocean, a harpoon gun might be a handy thing to have. At the local pool however, not only is having a harpoon gun completely unnecessary, but it's also a very real possibility that using your harpoon gun at the local pool will get you into a lot of trouble.
And now for some actual backup for my argument, rather than just posting a picture hosted on Picasa, I Googled the term "defragment flash media," and here are the first three relevant links. Each one gives the same message - don't defragment your flash media."
Click to expand...
Click to collapse
The rest of the thread explains it pretty clearly.

What Type Of MicroSDHC Class, Should I Buy For Arc?

Hey Ppl...
What Type Of MicroSDHC Class, Should I Buy For Arc?
Class 4, 6 or 10?
Right now i´ve Class 2

Its better to get the highest which is class 10 if u can afford..

The Classes guarantess a lowest speed while newely formated
class 2 is 2MB/s
class 6 is 6MB/s
class 10 is 10MB/s
and so on
but with luck a class 2 card can outpreform a class 6 card but you never know untill you have bought it.
the use of a higher class is more important how often you transfer big amout of files/data from and to your phone (this is when you will notice a slow card)
everyday use the class 2 card that is shipped with the phone works perfect

I'm going for a 16GB Kingston Class 10 for mine, might go 32GB but that'll depend on how much I get for my X10 on ebay.

XperienceD said:
I'm going for a 16GB Kingston Class 10 for mine, might go 32GB but that'll depend on how much I get for my X10 on ebay.
Click to expand...
Click to collapse
Put my X10 on ebay yesterday!
How much you asking for it?
For no OT, I bought a 32 GB Lexar class 10 MicroSDHC

LususNaturae said:
Put my X10 on ebay yesterday!
How much you asking for it?
Click to expand...
Click to collapse
Not sure yet, it's a bit weared so not expecting a great deal.

Here's the thing: the class of an SD card only defines how fast you can *write* to it. The read speeds of all cards tend to be the same regardless of class.
What a faster class of SD card will get you:
* faster copying of files from PC to SD, e.g. music, video
What it won't get you:
* a faster running phone (i.e. no 'snappier' performance)
* apps loading faster
* faster copying of files from SD to PC
* music/video playback improvements
* faster installation of apps - these are stored in internal memory, and even for builtin apps2sd the limiting factor tends to be the download speed
What it might get you:
* faster stills camera operation (havent checked for the arc, there may be bottlenecks elsewhere in the system, e.g. cpu)
* i thought it might solve the video capture glitching, but apparently the new firmware has fixed this regardless of SD card class.
* some apps which write a lot of data to SD card may run faster (note however that for most apps data is stored in internal storage)
Nothing inherently wrong with getting a faster card, just dont delude youself you'll see much of a difference in day-to-day operation.
Oh, i forgot, EXCEPT one other thing: If youre using 'full' apps2sd on a rooted phone (i.e. with an ext2 partition moving all apps+data+dalvik cache onto it) it will definitely help to have a faster class of SD card. Dunno if anyone really still does that these days...

I've always found going bigger and faster to be best, but valid points made.

daveybaby said:
Here's the thing: the class of an SD card only defines how fast you can *write* to it.
Click to expand...
Click to collapse
That's incorrect - the class rating is a guarantee of both read and write speeds.
daveybaby said:
The read speeds of all cards tend to be the same regardless of class.
Click to expand...
Click to collapse
You can't guarantee that any more than you can guarantee that a Class 2 card will write at speeds higher than 2MB/s.
The only way to be sure of getting a card that will read at a certain speed is to buy the appropriate class.

Step666 said:
That's incorrect - the class rating is a guarantee of both read and write speeds.
Click to expand...
Click to collapse
That's a nice opinion, but unfortunately it's just wrong.
Have a look at this. Notice they dont mention read speeds anywhere, that's because theyre already so fast regardless of class that it's irrelevant.
When you buy a class 10 SD card, youre spending your money on faster writes.
The read speeds of all cards tend to be the same regardless of class.
Click to expand...
Click to collapse
The limiting factor in read speeds is the interface, not the memory technology. I believe SDXC may have faster interface specs than SDHC (which in turn has faster specs than plain SD), but this is nothing to do with class, and make no difference if youre plugging them all into an SDHC device anyway.

Try reading that page again, it doesn't say that the class certification is a measure of writing speed, it says it's the bus-interface speed - it merely mentions write speeds as examples of why you would need higher speeds in real life.
The read speeds that the cards are actually capable of may well be higher but in practice the write speeds are almost always higher too - but there's no guarantee they are.

Step666 said:
Try reading that page again, it doesn't say that the class certification is a measure of writing speed, it says it's the bus-interface speed - it merely mentions write speeds as examples of why you would need higher speeds in real life.
Click to expand...
Click to collapse
So it's just a coincidence that nowhere does anyone mention read speeds, only write speeds and recording, when talking about flash memory. Because nobody's interested in read speeds, right?
Look, the read speeds of flash memory devices are stupidly high compared to write speeds (and always have been), and are limited by the interface, the write speeds are limited by the technology of the memory itself (which is the bit all of the manufacturers have spent millions (probably billions actually) improving over the last 10 years.
I hate quoting wikipedia articles but:
The Speed Class Rating is the official unit of speed measurement for SD Cards, defined by the SD Association. The Class number represents a multiple of 8 Mbits/s (1 MB/s), and meets the least sustained write speeds for a card in a fragmented state.[17]
These are the ratings of all currently available cards:[14][24]
Class 2, 2 MB/s
Class 4, 4 MB/s
Class 6, 6 MB/s
Class 10, 10 MB/s
Click to expand...
Click to collapse

I can see this going round in circles. From what I've read, basically, if you put a class 10 card in a phone that has been running a class 2 card then you're not going to see the difference like you would putting 4GB of memory in a PC that has been running on 512MB, but having a higher class of card will improve some areas behind the scenes so to speak.
If I didn't have an X10 to sell then chances are I'd stick with my class 6 Samsung but as I'll have the money to go class 10 I am doing.

daveybaby said:
Look, the read speeds of flash memory devices are stupidly high compared to write speeds...
Click to expand...
Click to collapse
And?
Real-world write speeds on cards are generally higher than their class rating would suggest but you are only guaranteed the speed corresponding to the class the card is.
Exactly the same applies to read speeds, they will most likely be much higher in real life but you are only guaranteed the speed that corresponds to the rated class of the card.
The class of a card guarantees minimum read and write speeds but both will likely be noticeably higher in real life.

Class has nothing to do with read speed period. Manufacturers only guarantees the write speed based on classifications because read speed will only be the same for all class of cards. Try the "Sd Tools" app if you don't believe me.
Therefore, unless you are using the defunct "app2sd+ data, dalvik", there should not be any discerning difference except for its higher price.
Sent from my LT15i using XDA App

Step666 said:
And?
Click to expand...
Click to collapse
And the read speed limit is defined by the interface implementation not by the class of the card. When i say flash read speeds (i.e. reading data from the cell) are fast, i mean theyre to all intents and purposes instantaneous, they always have been - they havent gotten any faster in the last 20 years - it's inherent in the technology. The thing that takes all the time is shuffling the bits of data across the serial interface.
It's entirely possible for a class 2 card by one maufacturer to have faster read speeds than a class 10 card by another manufacturer. It's entirely possible for the same card to have different read speeds in different devices due to the interaction of the interface implementations (subtle timing differences). Write speeds arent affected by this as much because the bottleneck is the large amount of time it takes to erase a cell and rewrite it.
Note that if you have a really old class 2 card, it's probably going to have much slower read speeds than a brand new class 10 card. This is not inherently due to the class of the card, it has everything to do with the fact that manufacturers only implemented faster interfaces to handle class 10 cards once the technology to *write* at this speed became available. Due to economies of scale they implement these faster interfaces across the board. New class 2 cards will be able to read as fast as new class 10 cards.
That's all i'm going to say on this matter, if you dont believe me you dont believe me, i'll agree to disagree.

daveybaby said:
That's all i'm going to say on this matter, if you dont believe me you dont believe me, i'll agree to disagree.
Click to expand...
Click to collapse
I'm afraid I don't, we'll have to disagree.

The sdhc that came in the box has a class 2 rating in it but using sd tools, it writes at 6mb/sec average, bursting at 9mb/sec. Read speed is the same as my older 8Gb class 6 at 19-20mb/sec.

Step666 said:
I'm afraid I don't, we'll have to disagree.
Click to expand...
Click to collapse
Cool

I have Sandisk Micro HDSD 16GB Class 2 but in SD Tools Write Speed: 10.1Mb/s, Read Speed: 27.5Mb/s

What is difference in SD card classes

Ok I have an Acer Iconia a500, currently I have only a 6gb card installed. Now when i look online i see that the micro sd cards are rated by classes. What is that for?
I need a 32gb for my Iconia. I do alot of school work from it. Just want the storage for my school books. any way, can someone break it down for me?
Thank You
Sent from my A500 using XDA Premium App

The SD card's class represents the least write speed.
Class 2: 2MB/s
class 4 : 4MB/s
and so on..

I think it's so you can copy and read files faster

ok, got it, higher the class the faster the write speed.
One more thing, now, the higher the class, does anyone know if they have more problems? like with crashing, or having to be re formatted often?

primus123 said:
ok, got it, higher the class the faster the write speed.
One more thing, now, the higher the class, does anyone know if they have more problems? like with crashing, or having to be re formatted often?
Click to expand...
Click to collapse
Nope, problems/crashing etc would be down to quality not size.
Also faster write speed doesn't mean it performs faster when used as a "hard drive" like in a phone, so lower class ones can outperform higher, but you'd have to try them to see.
It's because they're designed with things like cameras in mind, where getting the image saved quickly so you can take another one is the most important thing.
In a mobile phone/tablet they're accessed more randomly, and that is where it's been found that some higher class cards don't perform as well.

Mini SD cards, so tiny for my big hands.
Those mini sd cards are SOOOOO small, I've lost a few over the past 3 years.

so which one should i get for my iconia

androidappdeveloper said:
Those mini sd cards are SOOOOO small, I've lost a few over the past 3 years.
Click to expand...
Click to collapse
Tell me about it, I just reordered one after giving up the search on my current one. It's not completely lost, I'll probably come across it one day when re-organizing the room.

I keep mine in those Sd card cases and shove it in a crown royal bag....

You're probably fine with a Class 2 microSD card, as you won't have large files (or a large amount of small files) written in a short time.

Write speeds are generally the most important feature of a memory card. Write speeds determine the amount of time it takes to transfer the data, the moment you for example, click the button on your camera to ask the camera to take the image. You will probably remember that back in the early days of SD memory cards, there was an awful amount of lag time on cards, i.e from when you heard the click on the button (when you asked your camera to take the picture), to when you heard the double click (which is normally when the image has been written to the card).
Read speeds indicate the amount of time it takes for a card to transfer the data to a PC/Laptop. I.e the amount of time it takes to read the data off the card. Generally the higher the capacity of the card, this will naturally give a higher write speed. So if you have a 32GB card full of data and its only a class 2, it would take much longer than a 32GB card thats class 10, to send all the info to your pc etc.
Class 10 cards are recommended for HD video, or minimum class 6 really. You will probably find a 16GB class 4 card for example, will not work on say a Samsung HD Camcorder. It will maybe store only 1 minute of video, as for some reason the HD cannot write the data to the card fast enough it would seem.

Anyone ever lose a mini SDK card?

Plus your SD class is high, more it is fast...

jerryfranks said:
Anyone ever lose a mini SDK card?
Click to expand...
Click to collapse
Yes, almost (I found it after w hile), bloody spring so strong it shot across the room!
Pity there's not some little leatherette folder with tiny slots for a few MicroSD cards, I'd buy one!.

iloveapple said:
Write speeds are generally the most important feature of a memory card. Write speeds determine the amount of time it takes to transfer the data, the moment you for example, click the button on your camera to ask the camera to take the image. You will probably remember that back in the early days of SD memory cards, there was an awful amount of lag time on cards, i.e from when you heard the click on the button (when you asked your camera to take the picture), to when you heard the double click (which is normally when the image has been written to the card).
Read speeds indicate the amount of time it takes for a card to transfer the data to a PC/Laptop. I.e the amount of time it takes to read the data off the card. Generally the higher the capacity of the card, this will naturally give a higher write speed. So if you have a 32GB card full of data and its only a class 2, it would take much longer than a 32GB card thats class 10, to send all the info to your pc etc.
Class 10 cards are recommended for HD video, or minimum class 6 really. You will probably find a 16GB class 4 card for example, will not work on say a Samsung HD Camcorder. It will maybe store only 1 minute of video, as for some reason the HD cannot write the data to the card fast enough it would seem.
Click to expand...
Click to collapse
Very helpfully post,thanks.
Sent from my GT-I9000 using Tapatalk

Try to continue promoting of you site.

Hi speed cards are more efficient at presenting and recording. It's really up to you. If you buy the cheaper version and it doesn't present at the speed you think it should you'll have answered your own question.

You guys have it mostly right. The higher class your card is the faster it can write a file to its memory, the trade off is that the higher class cards have slower rapid access speeds, something to do with how it prepares files before writing. Basically, a class 10 will write a 1GB file faster, but if you try to write 15 3MB files quickly your performance will suffer. For something like a phone I recommend a class 4 or 6. For cameras I'd go higher (I don't know a whole lot about cameras).

seems like its good

Worth upgrading from c6 to c10 sd card

Hi,
i have the problem of not enough memory OR a slow system. Currently im using a class6 16gb microsd with default app2sd from the rom (JB spazedog), but the app data fills up the internal memory nonetheless. If i move everything (not just apps) to the sd the system is getting slow and unresponsive.
It is worth getting a faster sd (class 10) and moving everything to sd or do i have no choice but keeping apps to a minimum?
Thx

drdoomgod said:
It is worth getting a faster sd (class 10)?
Click to expand...
Click to collapse
No, but it would probably be worth to change to some rom which is not in beta and fits in /system small enough to have /data big enough to keep dalvik on nand and give more space for apps.

When using 6class and 10class i feel no significant changes in speed of app2sd area.
running speed test, write speed is usually about the same, read gives little higher results.
attachment below 16gb Transcend 10class vs Adata 8 gb 6class

I'm using ICS Spazedog and DiskManager is working fine. Sometimes I have to switch pages when looking at app storage to get it to work. Maybe it didn't install properly, maybe your partitions need to be aligned, maybe the SD card needs to be reformatted. Could be quite a few things doing it.

Nope

Class 6 -> 10
If you use App2SD, definitely no.
If you use Data2SD, it is possible to see some differences.

oxyg3n89 said:
When using 6class and 10class i feel no significant changes in speed of app2sd area.
running speed test, write speed is usually about the same, read gives little higher results.
attachment below 16gb Transcend 10class vs Adata 8 gb 6class
Click to expand...
Click to collapse
In terms of memory, you have to keep in mind that using a2sd means sending the dalvik (if you choose so) ans the app to the sd-ext. While it allows to more internal space, it still decreases.
The sd-ext partition is practically limited to 1024mb by the desire inter storage size too, meaning that going over 1gb of sd-ext size wouldn't be better.
Now like erklat said, it is better to switch to more stable ROM as JB ROMs offer few space and their behavior have not yet been standardized.
Recap: In terms of memory, it is not necessary to change to an upper class, but it is always a nice harmless improvement.
In terms of speed, I have seen that changing to class 10 gives great speed changes in terms of massive gaming:
Due to the higher read speed and also with the read ahead bumped I was able to increase greatly the loading time of such games as Modern Combat 3 and Nova 3. I was surprised since I thought that it was because of the processor mainly that it was so slow. There is an increase in performance when switching to an upper class, but frankly you cannot notice it unless you benchmark the results by testing with a ressource eater app.
To recap: It is worth the change only for the read speed. I'm not sure but I think that write speed is somewhat limited somehow by the hardware. (I'm thinking about windows here, if someone could confirm that please. )
________________________________
Please press thanks if I helped you in any way.
Sent from my HTC Desire using the xda app.

..

I am using class 10 transcend 8gb for spazedog JB rom and class 6 transcend 8gb for cm7 rom. No issues.
Sent from my HTC Desire using xda app-developers app