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SDHC 16gb

Hello, i am seeing a SD card to buy for my HTC TP, and by what i read here, they speak about class 5, class 4.... about classes...
And by what i saw on ebay, they speak it too, clan anybody explain for me what is it?
is it related with quality?
thanks

AFAIK there's only the following three classes: 2, 4 and 6.
They rate the read/write speed for that specific card.
"Class 2" means 2MBps minimum sustained write speed, and "Class 4" means 4MBps, and 6 for Class 6...
It's a different naming than "100x speed" but it classifies the cards speed in almost the same way... 'Almost' because the 100x speed indication mentions the top burst peaks, as opposed to the minimum sustained speeds...
Usually a Class 6 compares very well in terms of speed to a Sandisk Extreme IV (which is 133x speed)...
Also interesting to know: SDHC cards support FAT32, apart from more storagespace...
By the way and off the record: Google and Wikipedia seem vintage tools these days....took me more time to dig up from my own skull than looking it up...

Moaske said:
AFAIK there's only the following three classes: 2, 4 and 6.
They rate the read/write speed for that specific card.
"Class 2" means 2MBps minimum sustained write speed, and "Class 4" means 4MBps, and 6 for Class 6...
It's a different naming than "100x speed" but it classifies the cards speed in almost the same way... 'Almost' because the 100x speed indication mentions the top burst peaks, as opposed to the minimum sustained speeds...
Usually a Class 6 compares very well in terms of speed to a Sandisk Extreme IV (which is 133x speed)...
Also interesting to know: SDHC cards support FAT32, apart from more storagespace...
By the way and off the record: Google and Wikipedia seem vintage tools these days....took me more time to dig up from my own skull than looking it up...
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so, the best is class 6, no?

'fastest' is class 6, but atm, i believe there is only class 2 16gb sdhc, which is what i've got since mid december last year.

wanwarlock said:
'fastest' is class 6, but atm, i believe there is only class 2 16gb sdhc, which is what i've got since mid december last year.
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Class 4 16gb just came out http://www.symbian-guru.com/welcome...ssy-with-16gb-mobile-ultra-microsd-cards.html but its $119.99 My class 2 16gb from sandisk was $50.

not worth it yet... will wait a while to upgrade, but i think the speed would not be that much different

Inside your device, there's not much difference between different classes. Listening to music or watching videos doesn't really require all that much speed. But if you connect to your PC to transfer files a lot, then class 4 or 6 should be noticably faster.

Here is kingston 16GB for $38 http://www.buy.com/retail/product.asp?sku=210733297

off to hong kong next week
so hoping to get a cheap SDHC 16gb class 6 for my nikon D90

pkshr said:
Here is kingston 16GB for $38 http://www.buy.com/retail/product.asp?sku=210733297
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shame they don't ship to new zealand...

Class 4 SD good enough?

Currently I'm running a 16gb class 2 that I've had since the 16gb's have been out.(used in my Nokia N800) I found a 16GB class 4 on sale in town for $69 where a class 6 is $120. My question since it hasn't been confirmed (or I suck at searching) does the Magic actually take advantage of the class 6 or with the class 4 be good enough? Thanks for any info on this.
Clinton

IMHO I think your better off with a 16gb class 6, as it is recommended for many hacks Android related. Also you could probably find it cheaper online unless Monet is not an issue.

Just rather buy in town, not a big online buyer. I've read that the class 6 is the only way to go for apps 2 SD and the like but I just wanted to have faster access times to music, video and pictures really. That's pretty much all I have on the card, maybe a few docs but nothing I need to access quickly. If the music/video player or Quick office wont see/use the extra speed increase I'd rather save the cash for a nice set of headphones or case etc..
Clinton

Well the classes indicate how fast the SD card is. Class 2 = 2 MB/s, Class 4 = 4 MB/s and so on, so you would feel a difference between the two.

Cheesebaron said:
Well the classes indicate how fast the SD card is. Class 2 = 2 MB/s, Class 4 = 4 MB/s and so on, so you would feel a difference between the two.
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Very useful. I know the difference between card speeds, what I was asking is if the Magic can take advantage of the speed increase or is there a limit? I know in using my Nokia N800 (Linux OS) even the moded kernel only took advantage of the class 4 cards and there was no benefit to the class 6.
Clinton

The SD Speed Class Ratings specify the following minimum write speeds based on "the best fragmented state where no memory unit is occupied":
Class 2: 2 MB/s
Class 4: 4 MB/s
Class 6: 6 MB/s
The Class system is a minimum speed that it should perform at, if you are lucky it will work closer to the next class speed, as most cards actually perform faster then their class.
I have an 6GB class 4 sdhc card and the transfer speed is generally around 9-11 mb/s.
If you are putting a swap file on to your sdhc, a class 4 should be a minimum class you are to look for.
Personally, I use Crystal DiskMark to test the write-transfer-speed of my cards. http://crystalmark.info/software/CrystalDiskMark/index-e.html

id242 said:
The SD Speed Class Ratings specify the following minimum write speeds based on "the best fragmented state where no memory unit is occupied":
Class 2: 2 MB/s
Class 4: 4 MB/s
Class 6: 6 MB/s
The Class system is a minimum speed that it should perform at, if you are lucky it will work closer to the next class speed, as most cards actually perform faster then their class.
I have an 6GB class 4 sdhc card and the transfer speed is generally around 9-11 mb/s.
If you are putting a swap file on to your sdhc, a class 4 should be a minimum class you are to look for.
Personally, I use Crystal DiskMark to test the write-transfer-speed of my cards. http://crystalmark.info/software/CrystalDiskMark/index-e.html
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Thanks I know the speed rating and how they are tested.
I'm not going to be putting a swap on the card or doing apps2sd, it's a Rogers Magic doesn't need either.
Thanks for the link to the speed test, didn't have one.
Does your class4 card give you any troubles at all or have you found it to be up to pare in all your storage needs? Thanks for the reply.
Clinton

Clinton, I mostly use the spare ion for simple photo taking, jotting-down notes and listening to podcasts (via meridian)/streaming radio (via stream furious) in my car. I haven't ever had any problems with it's speed.
I've had the stock 2gb in it for about 2 weeks, then a kingston 6GB class 4 in it for about a month and just this afternoon, picked up a polaroid 8gb class 6 (for $17.99 from Fry's Electronics - in-store).
the only time I have really had any problems with the speed of microsd card was when using them on my DS through r4 or supercard flashcarts. but that was back when 2gb microsd was just hitting the market (that 2gb kingston microsd from verizon was $99. in the USA, verizon was the first to publically sell this size card)
I generally try to stay away from class 2 cards just as one would try to stay away from USB 1.x devices.
without installing any additional software, a quick and simple test to check if the card is quick enough for heavy usage on your phone, might be to test if Vista/Win7 will accept it as ReadyBoost Compatible.

MicroSD Cards: Speeds?

I was told when I bought my phone that the Legend is optimized to work with up to 32GB MicroSD, but the transfer rate of data and general data speeds are at peak with certain capacity MicroSD cards. Has anyone else heard this or similar?

It just depends on what class you get, which will improve transfer rates, for example I have a class 6 8GB in mine now and it flies. btw the higher the class the better (the class is displayed with a circle around it on the card.
Sent from my HTC Legend using XDA App

That's not completely true.
The card's class isn't it's real speed, but the guaranteed one (in read AND write).
I remember having seen a test about µSD cards which shown that Sandisk are one of the best brands.
I bought a Sandisk 8GB "Ultra" micro SD for 20 bucks, and even though it's only class 2, it can go up to 20MB/s read and 7-8MB/s write (in case of large files of course).

[Q] Micro Sd class 10 or class 6?

I'm looking to buy a new MicroSD and wondering if getting a class 10 over a class 6 would make a significant difference to the phone (if im using data2sd and or apps2sd)
Thank you!

I think the difference between class 6 and 10 would feel minor, where-as the difference between the class 2 and class 6 feels huge.
And since this is the Vibrant forums, I should mention that the internal memory in the phone is very fast. I tested it at over 10MB/s write on my first phone. My second phone its closer to 6 MB/s write. So you apps and stuff should run perfectly fine from the internal app storage.
I should also mention that I purchased the new kingston micro sd thats rated class 4 but claims speeds upto class 10. Upon testing that I got 9 MB/s write. ($28 after $10 reward from buy.com). My previous class 2 16GB card tested it 2.6 MB/s write for comparison.

Shane_pcs said:
I think the difference between class 6 and 10 would feel minor, where-as the difference between the class 2 and class 6 feels huge.
And since this is the Vibrant forums, I should mention that the internal memory in the phone is very fast. I tested it at over 10MB/s write on my first phone. My second phone its closer to 6 MB/s write. So you apps and stuff should run perfectly fine from the internal app storage.
I should also mention that I purchased the new kingston micro sd thats rated class 4 but claims speeds upto class 10. Upon testing that I got 9 MB/s write. ($28 after $10 reward from buy.com). My previous class 2 16GB card tested it 2.6 MB/s write for comparison.
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Just to help out here...
the difference between class 2 and class 6 is the exact same as class 6 and class 10. Remember the cd-rom speeds (52x, etc)? That's how the speed is calculated for a SDHC card. So a class 2 = 2x cdrom, class 6 = 6x, class 10 = 10x.
whether our hardware has capability to handle what a class 10 can do, that I don't know. I'd definitely advise to get something with more space than a 2GB card though - I'm not sure everyone needs a 32 (personal opinion/long discussion), but I absolutely agree it should be improved upon.

designerfx said:
Just to help out here...
the difference between class 2 and class 6 is the exact same as class 6 and class 10. Remember the cd-rom speeds (52x, etc)? That's how the speed is calculated for a SDHC card. So a class 2 = 2x cdrom, class 6 = 6x, class 10 = 10x.
whether our hardware has capability to handle what a class 10 can do, that I don't know. I'd definitely advise to get something with more space than a 2GB card though - I'm not sure everyone needs a 32 (personal opinion/long discussion), but I absolutely agree it should be improved upon.
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I understand that, thats why i picked those classes. But my point is that a class 6 card is 3x the speed of a class2 where class 10 isnt even twice as fast as the class 6. So the perceived difference is smaller, even though the technical difference is the same.

I'm still running a class 2 and I've been wondering if this is holding me back on this phone (card was previously in my G1).
Will the lower classes function the same (creating ext2 etc...) it's just a matter of speed? Just wondering if there's anything that simply can't be done with a class2 or even 6 that could be done with a 10.

CapitalM3 said:
I'm still running a class 2 and I've been wondering if this is holding me back on this phone (card was previously in my G1).
Will the lower classes function the same (creating ext2 etc...) it's just a matter of speed? Just wondering if there's anything that simply can't be done with a class2 or even 6 that could be done with a 10.
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Just cost you more. Do you really need a class 10 for this phone? Avatar is on a card that isnt even a class 2.

Vegastouch said:
Just cost you more. Do you really need a class 10 for this phone? Avatar is on a card that isnt even a class 2.
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xD What class was the stock sd card?

I only ever see class 6+ cards being used in higher end compact cameras and SLRs.
Putting anything higher than class 6 in a phone your using for apps/music/movies isn't needed and just a waste of money.
I've also seen a lot of people saying the memory card speeds with the galaxy s are bottlenecked right now, so your not even going to get top speeds with a class 6.

Vegastouch said:
Just cost you more. Do you really need a class 10 for this phone? Avatar is on a card that isnt even a class 2.
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While the card isn't marked, it tests out at just over 4MB/s which would put it in a class 4.
And we should be clear that the class refers to the write speed. A class 2 will read at 10 MB/s just like the other classes. Where you run into issues with class 2 cards is when you start modding or running programs from the sd card. If you use the card for a swap partition or something the write speed now plays a major factor in the usefulness.
If all you want it for is to place your music files on there and listen to them, then a class 2 will be plenty. That was my initial thought when I bought my 1st 16 GB card for my mytouch3g. Then I got into custom roms and found myself limited.

How do you test the speed of the SD card?

What size microsd card are you looking for? If its a 32GB, I have only seen a Sandisk microsd in Class 2. As far as I know there are no higher classes at this time. Hopefully that will change soon. I would like to get all of my music onto one 32gb card.

designerfx said:
Just to help out here...
the difference between class 2 and class 6 is the exact same as class 6 and class 10. Remember the cd-rom speeds (52x, etc)? That's how the speed is calculated for a SDHC card. So a class 2 = 2x cdrom, class 6 = 6x, class 10 = 10x.
whether our hardware has capability to handle what a class 10 can do, that I don't know. I'd definitely advise to get something with more space than a 2GB card though - I'm not sure everyone needs a 32 (personal opinion/long discussion), but I absolutely agree it should be improved upon.
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This isnt exactly true. with cdroms the X stands for how much faster it would spin in relation to a audio cd. So 1x ment it spun at the same speed as a audio cd. 2x was twice, ext ext. And this was a max speed.
Classes for SDCard stands for the minimum transfer speed. class two is at least 2mbps, class 6 is 6mbps, and so on.

frankencat said:
How do you test the speed of the SD card?
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google FDbench
it will test the read and write speed as well as operations per second.

I still can't find a 32gb microsd class 10, anyone find one for sale?

Class 10
Class 10 limitation presently is 8 gig for all brands except the Kingston and soon to be released Silicon Power. The Kingston brand never benches as advertised, so they are not reliable from my point of view. Silicon power has been pretty solid on their claims from my testing versus their claims, but I have not yet got my hands on the latest class 10 16 gig, I have been trying to buy for the since 10-1-2010 but not out in USA yet.
Kingston (in my opinion) is rife with false claims and I find their products have always been sub par.
Flashing and alike works better with class 6 over class 2 & 4. So, if you really want more memory the only 32 gig class 6 I have seen advertised (amazon) are: Transcend, Centon, and Komputerbay (what a name?!) 32 gig Class 6
Other than that, we wil just have to wait until they get the algorithm figured out for a micro ad card with that much ram and that fast.

Get the app "sd card speed test" it works ok Im sure there are others as well

I imagine the only reason you would need a Class 6 card or above is if you plan to take a lot of HD video. Apart from that, even a Class 2 is fast enough to keep up with the still camera, not to mention anything that just requires reads, like music or movie playback.
As for running apps off an external SD card, why would you ever want to do that? You can load close to 2GB on the internal app space, which is likely way faster than any mounted external SD card. I feel like an app whore and I'm not even close to using half that space. By the time apps start getting large enough that it's an issue, we'll be on the Vibrant 2 or beyond.

glad that you asked
merrifield69 said:
I'm looking to buy a new MicroSD and wondering if getting a class 10 over a class 6 would make a significant difference to the phone (if im using data2sd and or apps2sd)
Thank you!
Click to expand...
Click to collapse
because I just picked up a 16G class 10 by WinTec last week and it is VERY fast from boot up with 9G occupied from 15G available (wondered 1G gone to? and that is a lot of gone G lol). It was $42 wo tax expensive but so far the fastest.

Whoohoo
mine 16G class 10 tested 2x >8M and 1x >9M write, 3x > 18M read and it was probably so fast that the result said "unknown class" lol. x means 1 run with 2MB buffer setting. Downloaded app call SD card speed tester.

There are now some 32GB class 6 SDCARDS on the markey, and with 2.2 and installing apps to SD that might matter. It might also matter if you have a TON of music and images, as "Scanning SD for Media" would be faster.
You will pay money for the time savings though.

[Q] What is better about a class 10 mico sdhc compared to a class 2?

I am about to buy another micro sdhc card and was wondering what the big difference between the two would be between the classes. I already know what the classes mean, class 2 means it will write at 2 megabits a secound, where as 10 writes at 10 megabits a secound.
My question is what would that extra speed allow you to do what you wouldn't be able to do before. Where would a fast card really shine. is there a maxamium speed that the phone can run at.
would it be better for running android sd, linux in a virtul machine on android (forgot what that is called) watching movies on sd, or apps, games on sd
i also have a asus transformer 10" honeycomb tablet would that i might use it in.

does anybody know?

Doesn't really make a big difference in running an SD Android build. I've been running multiple SD builds on the 16gb class 2 that came with my HD2 for like 2 years, and it is butter smooth. I've seen people on the HD2 forum who bought class 10 cards and had problems. The standard answer that you'll usually find around here about SD cards is that it's pretty much a hit-or-miss thing.
I personally wouldn't waste my money on a more expensive card just for faster write speed, since it seems like if it makes a difference at all, its a negligable difference.

Class is a measure only used on microsd. It means the sdcard MUST be able to withstand writing to it at 10mb/s. So yeah, a class10 should be better than a class2.
Wikipedia
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 Mbit/s (1 MB/s), the least sustained write speeds for a card in a fragmented state (Class 2, 4, 6) or the minimum non-fragmented sequential write speed (Class 10).
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In reality...
No one guarantees that the sdcard reader/writer can write to it at the given speed (or even needs to). Also, many times de class is a basic measure. My 16gb class 10 can be written (on a computer) at 21mb/s tops. Many class2/4 can be written at class10 speeds or above. It's just a guarantee. As a user rarely writes data sequentially, a class 6 should be enough, making a class 10 better only when copying LARGE files (ex. mp3) to the card.
Now, i've never seen, and there's no statistic that class X cards are better than class Y. There are brands better than others, but that's it.
BTW, in Android at least (this must apply on other OS's), increasing sdcard cache to 1024 or above (at a maximum of 2048) improves write speed immensely.

Class 10 will give you faster speed when you transfer large files from pc to card ( videos updated gps map etc ) but I also read somewhere that higher class card uses more battery even in standby . Class 4 should be more than good .

budalica said:
Class 10 will give you faster speed when you transfer large files from pc to card ( videos updated gps map etc ) but I also read somewhere that higher class card uses more battery even in standby . Class 4 should be more than good .
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Make it 6... faster non sequential write speed