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I manage a consumer electronics store and a lot of people seem to be misinformed when shopping for memory cards for new mobile devices. After spending a year or so on this site it seems many people here are misinformed as well- so I thought I would open up a discussion.
When looking at memory cards (micro in this case; but most follow the same format) there are 3 important pieces of information to review.
1. Capacity- some people will do fine with a 1gig card while others use their device to store music, movies, and pictures and need more space. At the time of this post the largest micro-SD card available (as far as I know) is 16gig.
2. Speed rating- obviously you want the most performance you can get out of a memory card so any information stored on that card can be accessed quickly, and with so many new ROM's running apps from the SD card the transfer needs to be both fast and efficient. Most cards offer anywhere from 6mb/sec to 15mb/sec (with other types of flash speeds near the 45mb/sec range). The speed rating is a rating of the MAXIMUM READ/WRITE SPEED capabilities, and is often difficult to find on the product info- even more difficult to measure.
3. Class rating- is the most misunderstood rating of all- and the most advertised (the class rating is written on the front of most cards). The class rating IS NOT a measure of how fast information can be accessed from the card by the device. Most people believe that a class 2 card is guaranteed to read/write at 2mb/sec while a class 6 is guaranteed to read/write no slower than 6mb/sec, the next logical step is to believe that a class 6 card will be faster and more efficient than a lower class. THIS IS NOT TRUE. What the class rating is actually defining is whether or not the card will work in your device. A class 6 card will only function properly in a device that can SUSTAIN a write/read speed of 6mb/sec. Where a class 2 card (with the same speed rating) will work in any device that can write at least 2mb/sec or more; and will do so AT THE SAME SPEED AS THE CLASS 6.
Many people believe that the discrepency lies in the branding of the card, for example some say that no-name brands will produce a substandard card and call it a "class 6", which will result in lower transfer speeds. Again, this is not true. The class rating HAS NOTHING TO DO WITH HOW FAST THIS CARD WILL PERFORM. If your device reads/writes at 15mb/sec it will perform the same with a class 2 as it will with a class 6. The only time class ratings matter is if you have a device (usually a digital camera) that writes slower than 6mb/sec- which the G1 does not.
I don't understand why ROM developers (and no disrespect intended, I have an unbelieveable respect for devs) make a notation that HERO ROM's need a class 6 memory card to function. We sell 16gig Sandisk microSD cards with a class 4 rating, and I constantly get customers who tell me they are going to wait for Sandisk's class 6 16gig microSD card. As of today Sandisk has no intention of making a class 6 16gig microSD card. And if they did, it would not be any faster than the class 4 that is currently available.
This is the information I have gathered by speaking to the Sandisk and Delkin engineering departments as well as countless searches, and I hope it saves someone some $$- which is my intent.
hmm.. your post does not quite make sense.. so you say a class 2 card in a G1 performs equally fast as a class 6. And that class rating has nothing to do with card speed....
A bit hard to believe....
ofsinreno said:
I manage a consumer electronics store and a lot of people seem to be misinformed when shopping for memory cards for new mobile devices. After spending a year or so on this site it seems many people here are misinformed as well- so I thought I would open up a discussion.
When looking at memory cards (micro in this case; but most follow the same format) there are 3 important pieces of information to review.
1. Capacity- some people will do fine with a 1gig card while others use their device to store music, movies, and pictures and need more space. At the time of this post the largest micro-SD card available (as far as I know) is 16gig.
2. Speed rating- obviously you want the most performance you can get out of a memory card so any information stored on that card can be accessed quickly, and with so many new ROM's running apps from the SD card the transfer needs to be both fast and efficient. Most cards offer anywhere from 6mb/sec to 15mb/sec (with other types of flash speeds near the 45mb/sec range). The speed rating is a rating of the MAXIMUM READ/WRITE SPEED capabilities, and is often difficult to find on the product info- even more difficult to measure.
3. Class rating- is the most misunderstood rating of all- and the most advertised (the class rating is written on the front of most cards). The class rating IS NOT a measure of how fast information can be accessed from the card by the device. Most people believe that a class 2 card is guaranteed to read/write at 2mb/sec while a class 6 is guaranteed to read/write no slower than 6mb/sec, the next logical step is to believe that a class 6 card will be faster and more efficient than a lower class. THIS IS NOT TRUE. What the class rating is actually defining is whether or not the card will work in your device. A class 6 card will only function properly in a device that can SUSTAIN a write/read speed of 6mb/sec. Where a class 2 card (with the same speed rating) will work in any device that can write at least 2mb/sec or more; and will do so AT THE SAME SPEED AS THE CLASS 6.
Many people believe that the discrepency lies in the branding of the card, for example some say that no-name brands will produce a substandard card and call it a "class 6", which will result in lower transfer speeds. Again, this is not true. The class rating HAS NOTHING TO DO WITH HOW FAST THIS CARD WILL PERFORM. If your device reads/writes at 15mb/sec it will perform the same with a class 2 as it will with a class 6. The only time class ratings matter is if you have a device (usually a digital camera) that writes slower than 6mb/sec- which the G1 does not.
I don't understand why ROM developers (and no disrespect intended, I have an unbelieveable respect for devs) make a notation that HERO ROM's need a class 6 memory card to function. We sell 16gig Sandisk microSD cards with a class 4 rating, and I constantly get customers who tell me they are going to wait for Sandisk's class 6 16gig microSD card. As of today Sandisk has no intention of making a class 6 16gig microSD card. And if they did, it would not be any faster than the class 4 that is currently available.
This is the information I have gathered by speaking to the Sandisk and Delkin engineering departments as well as countless searches, and I hope it saves someone some $$- which is my intent.
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Sigh... read this.
See how it says the Class Rating is the minimum read/write speed? Crazy that you would say it has nothing to do with speed. One thing though, manufacturers rarely advertise the MAX speed of the cards, which is why some Class 4 cards are equal or greater than some Class 6, also attributed to manufacturers claims of speed not being substantiated.
Insert foot in mouth, walk away.
Wow, so much misinformation there.
http://en.wikipedia.org/wiki/Secure_Digital
SD Cards and SDHC Cards have Speed Class Ratings defined by the SD Association. The SD Speed Class Ratings specify the following minimum write speeds based on "the best fragmented state where no memory unit is occupied"
Edit: Damn, daveid beat me to it.
The minimum write speed that defines the class rating is not the minimum speed the card is guaranteed to read/write, but the minimum speed a device that can be used. If your device only writes at 4mb/sec you must use a class 4 or lower.
http://kb.sandisk.com/app/answers/d...ce between speed and class rating/r_id/101834
ofsinreno said:
The minimum write speed that defines the class rating is not the minimum speed the card is guaranteed to read/write, but the minimum speed a device that can be used. If your device only writes at 4mb/sec you must use a class 4 or lower.
http://kb.sandisk.com/app/answers/d...ce between speed and class rating/r_id/101834
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If you read the page you quoted, you would understand how you are wrong.
Speed Class is a minimum speed based on a worst case scenario test.
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Unlike card write speeds that measure maximum performance, class ratings measure the minimum sustained speed required for recording an even rate of video onto the card. The class rating number corresponds to the transfer rate measured in megabytes per second. Class 2 cards are designed for a minimum sustained transfer rate of 2 megabytes per second (MB/s)1, while Class 10 cards are designed for a minimum sustained transfer rate of 10MB/s2.
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I would read that again if I were you.
It is saying that if you have a camcorder that requires a class 4 card and you put in a class 2, it may not function correctly.
Lower speed card in a camera that requires a higher speed = bad
Higher speed card in a camera that requires a lower speed = good
I know the wording is a bit confusing on this issue. I had to call the tech support line at Sandisk when we first got the 16G class 4 cards myself to find out what the difference was. As a manager it is my responsibility to know what our customers need before issues arise. The explanation I am providing is the explanation I was given by both the tech support associate and the engineer I was later able to speak with. When I called Delkin to ask the same question I was told the same thing. If my information is incorrect I am sorry but it came directly from the horse's mouth.
I posted "A discussion"- at least we have that! I love xda
What you are saying doesn't make any sense. By your logic a class 2 card would actually be better than a class 6. If that was true, why are they cheaper.
ofsinreno said:
I know the wording is a bit confusing on this issue. I had to call the tech support line at Sandisk when we first got the 16G class 4 cards myself to find out what the difference was. As a manager it is my responsibility to know what our customers need before issues arise. The explanation I am providing is the explanation I was given by both the tech support associate and the engineer I was later able to speak with. When I called Delkin to ask the same question I was told the same thing. If my information is incorrect I am sorry but it came directly from the horse's mouth.
I posted "A discussion"- at least we have that! I love xda
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The problem with your argument is that based on your logic the following scenario would result in poor performance.
Let's just say I have a digicam that can only sustain a max write speed of 6mb/s. I purchase a class 10 card for it (because it is on sale, and has a bigger number).
Based on your explanation, that would result in worse performance than getting a class 6 card, or that it would not work at all.
However, class ratings have nothing to do with the Standard that SD is built on (and MicroSD), this standard requires devices to be compatible (the newer SDHC classification is an extension on the original SD standard that allows for higher capacity, this requires two devices that are SDHC compatible). ANY SD or MicroSD card should be compatible with ANY device that supports SD or MicroSD (respectively, and of course minding the HC requirements if needed).
In fact, the Class 10 card WILL work in a device that can only sustain 6mb/s speeds. Not only will it work, it will work just as well as the Class 6 would. But, it will provide better transfer speeds when utilized in a card reader or other device. Thus, making it the better choice.
ofsinreno said:
I know the wording is a bit confusing on this issue. I had to call the tech support line at Sandisk when we first got the 16G class 4 cards myself to find out what the difference was. As a manager it is my responsibility to know what our customers need before issues arise. The explanation I am providing is the explanation I was given by both the tech support associate and the engineer I was later able to speak with. When I called Delkin to ask the same question I was told the same thing. If my information is incorrect I am sorry but it came directly from the horse's mouth.
I posted "A discussion"- at least we have that! I love xda
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So very generally (this doesn't apply to all cards, but probably a majority of them.) A Class 4, 100x card (if such a card existed) would probably sustained write to the card at 5MB/s and sustained read from the card at about 14MB/s. While a Class 6, 66x card would probably sustained write to the card at around 7MB/s and sustained read from the card at around 9MB/s. I can make this generalization because most of the time (not always though) reading from a microSDHC card is faster than writing.
But here is the kicker, a class 6 SDHC card is the maximum class at this time. Some class 6 cards could actually be "Class 10" if it existed. My class 6 SanDisk 8G would be one of these cards. I have benchmarked it at a sustained ~14MB/s write and ~20MB/s read. So that is why people are waiting for SanDisk Class 6 cards. Because generally, SanDisk class 6 cards are a lot higher spec than they need to be in order to satisfy the current class ratings.
However like daveid said, the speed ratings are rarely put on SDHC cards. Only class ratings.
So, I said all of that to say this. If I needed a card for my camera (which the write speed is important,) I would pick the class 6 card in the example. If I needed a card for my music player for my truck (in which read times are the most important) I would get the class 4 in the example above.
However, in the real world, since the X rating is rarely specified, I would play it safe and get the class 6 rated card in both examples.
t1n0m3n said:
So very generally (this doesn't apply to all cards, but probably a majority of them.) A Class 4, 100x card (if such a card existed) would probably sustained write to the card at 5MB/s and sustained read from the card at about 14MB/s. While a Class 6, 66x card would probably sustained write to the card at around 7MB/s and sustained read from the card at around 9MB/s. I can make this generalization because most of the time (not always though) reading from a microSDHC card is faster than writing.
But here is the kicker, a class 6 SDHC card is the maximum class at this time. Some class 6 cards could actually be "Class 10" if it existed. My class 6 SanDisk 8G would be one of these cards. I have benchmarked it at a sustained ~14MB/s write and ~20MB/s read. So that is why people are waiting for SanDisk Class 6 cards. Because generally, SanDisk class 6 cards are a lot higher spec than they need to be in order to satisfy the current class ratings.
However like daveid said, the speed ratings are rarely put on SDHC cards. Only class ratings.
So, I said all of that to say this. If I needed a card for my camera (which the write speed is important,) I would pick the class 6 card in the example. If I needed a card for my music player for my truck (in which read times are the most important) I would get the class 4 in the example above.
However, in the real world, since the X rating is rarely specified, I would play it safe and get the class 6 rated card in both examples.
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I've got the same Sandisk card they're freakin BEAST!!! speed ratings over class ratings seriously. oh wait they have money to make
OK, I don't mind admitting that my foot often finds its way to my mouth. I logged onto a training site we use at work and found this:
"Read/Write speed is the maximum sequential speed that data can be written to the memory card ("write speed") and transferred to a host device ("read speed")."
and this
"Speed class is not a measure of the top sustained speed of an SD/SDHC memory card. The current SD/SDHC memory card speed classes are generally rated as class 2, class 4, or class 6. "
and this
"Usually standard definition camcorders require only a Speed Class 2 rating
Generally standard definition camcorders will not benefit by using higher class 4 or above memory card products
and this
"Maximum read / write speed (MB/sec), not class speed, is the critical number for you and your customers who want to take photos"
Taking the information given to me by the company representatives and applying this Sandisk Training information I came up with the information I posted earlier. And I thought that people were being misled into spending more $$ than necessary.
Thanks for the discussion, now I understand
It is great to help people reach a higher understanding of things!
And I am glad you saw our input as that, instead of getting hurt feelings like some people do.
I'm sorry I'm so late to this conversation, but is there anything wrong with getting a class 10 mSDHC card that is going to be partitioned? I wouldn't think so... but I wouldn't want to spend the money and realize that the ext partitions do not work with a class 10 card. Has anyone tried this? Results? Noticeable performance shift?
Jeliz187 said:
I'm sorry I'm so late to this conversation, but is there anything wrong with getting a class 10 mSDHC card that is going to be partitioned? I wouldn't think so... but I wouldn't want to spend the money and realize that the ext partitions do not work with a class 10 card. Has anyone tried this? Results? Noticeable performance shift?
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lol^^ i was about to ask the same exact thing....cus I got my eye on the new Kingston 10 class 16gb card right now...but haven't heard too much talk about it, so I figured I'd wait until more people purchase and give feedback before I spend that $100.
also, has anyone ever used a "Centon" sdcard? Unfamiliar name to me, I usually buy Sandisk or Transcend.....but I took a risk and purchased a 16gb Class 6 Centon sdcard yesterday in TigerDirect. Cost me $74! Have not opened it yet, and I still have the receipt....any suggestions?
Personally I would wait until "Class 10" becomes an official SD Association speed class. You never know, they may spec other classes like "Class 12" or "Class 14" at that time as well. However, for the G1, you will probably not get any performance increase over a Class 6. A fast Class 6 pretty much maxes out the G1's capabilities as of right now.
So unless you are getting the new card to put into an adapter and push large file directly to the card (bypassing the G1) I would hold off getting the expensive "Class 10" card until more info is given. (I.E. an official SD Card Specification Ver.3.0 is released.)
hi, I have a question related with the SD card. I also have a Class 6 8G card, but I can't use adaptor to read it on my card reader. The card reader is a bit old. It's a kind of 6-in-1 reader and I usually read my CF card from DSLR camera on it and till now it's working fine. However, ever since I purchased this microSD card, I can't read it on the card reader. everytime I put it into the adapter and inserted it in the card reader, it will cause the card reader malfunction. nothing can be read and the LED on the reader just die.
Is it because the reader can't support it or the adapter can't? I can only use the phone to read the card now.
zhourj said:
hi, I have a question related with the SD card. I also have a Class 6 8G card, but I can't use adaptor to read it on my card reader. The card reader is a bit old. It's a kind of 6-in-1 reader and I usually read my CF card from DSLR camera on it and till now it's working fine. However, ever since I purchased this microSD card, I can't read it on the card reader. everytime I put it into the adapter and inserted it in the card reader, it will cause the card reader malfunction. nothing can be read and the LED on the reader just die.
Is it because the reader can't support it or the adapter can't? I can only use the phone to read the card now.
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Do you have it partitioned with an ext file system? If so then windows has a hard time recognizing this. Its better to just mount your mSDHC from your phone instead of trying to mount it through a card reader.
yes, I did have ext file system on it , but also fat 32. I got another newer reader and it can read the fat 32 partition. I think the other one just being too old and can't read the sdhc card . it's too large for it.
So I ended up ordered a 32gb micro SD card off amazon without realizing the class until yesterday and it was too late to ship it. So I come here asking should this be okay for my TF?
I know the speeds will be slow but if that's all it is I can deal with it. My main concern is I have a lot of 720p & 1080p videos and I don't want them to lag. Will there be any lag when using this card, or should I just go ahead and return it?
Let me know if this has been asked or is in the wrong section. Thanks
That class doesnt have anything to do with read speed, only write speed. So a class two *should* be slower to write videos to it than a class four but read wise both should be much faster. Of course the actual speeds can vary by maker.
So, yes, a class two will be fine for playing HD video.
I've been using good quality (Sandisk) microSD cards Android devices for a long time now and *never* had an issue with them.
Remember the following:
1. The class of an SD card doesn't tell you how fast it is - it only really tells you how slow it isn't!
2. It only tells you the minimum sustained write speed in optimal conditions (i.e. unfragmented), and nothing about read speeds at all.
3. Good quality lower "class" cards can often exceed the class minimums for higher classes anyway. For example, I've several 16gb Class 2 Sandisk microSDs and in my testing can regularly achieve write speeds of 7MB/s with all of them.
Regards,
Dave
Cool, thanks a lot! If I ever get tired of the write speed I'll just grab another one later on down the line. Thanks again
Just to add my voice in agreement with the above posts:
Class 2 Sandisk cards are fine, even for 1080p files.
There is a lot of misinformation out there regarding Class speeds on microSD cards.
I've watched a 1080p high profile MKV with a video bitrate of 9500kbps on my Galaxy SII on a Class 2 card, no problems.
Heres my video showing exactly that:
Yep I've used C2 Sandisk and PNY cards without any problems.
hello i just got an amaze and with its camera and video quality i think i need a better sd card as my current one is class 2. any recommendations and letting me me know what the phone can handle without paying for more than i need would be greatly appreciated.
thanks very much
The Amaze can handle a class 10 memory card. This would be preferred as it has the fastest read and write speed that I know of. I am currently using a 16GB class 6 SanDisk and it works really well.
Hope this is helpful. Or maybe someone else can give you more info.
Sent from my world to yours using an HTC Amaze
windcan said:
hello i just got an amaze and with its camera and video quality i think i need a better sd card as my current one is class 2. any recommendations and letting me me know what the phone can handle without paying for more than i need would be greatly appreciated.
thanks very much
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This should do the trick.
http://www.amazon.com/AmazonBasics-...H4U0/ref=sr_1_2?ie=UTF8&qid=1325371114&sr=8-2
Looks like it may be worth it to go straight to class 10.
Thanks
PNY class 10.
Sent from my HTC Amaze 4G using xda premium
I just got a Samsung 32gb class 10 and it works great.
what is "PNY"?
windcan said:
what is "PNY"?
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PNY is just a brand
Picked up a Lexar 32gb class 10 for $45 on boxing day. (for you Americans, that's the day after Christmas)
lol
marleyfan61 said:
Picked up a Lexar 32gb class 10 for $45 on boxing day. (for you Americans, that's the day after Christmas)
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Sent from my HTC Amaze 4G using XDA Premium App
Confused
My Amaze is on it's way to my door this Wednesday, and I too am on the hunt for a good class 10 micro SD card. I had a Patriot 32 GB ordered from Amazon (it had 4+ stars), but then I started reading specific user ratings. It almost looks as though there is a problem with quality/consistency with many of the 32GB class 10s. The Patriot, and several others, had quite a few recent users complain that their class 10 doesn't run any faster then their old class 2 or 4. (The complaints I tried to focused on are from users who had run speed tests and didn't just provide seat-of-the-pants analysis.) Admittedly, I was going for as cheap as I could (the Patriot was only $47), but I looked at several others and they had spotty speed comments as well.
Does anyone have specific knowledge or insight on this? Is it an issue with lower cost manufacturers whereby one card is great but the next can be dreadful. Is it the nature of the beast?
I appreciate your comments.
A class 10 card isn't the way to go with smartphones. Best to get a class 4.
Sharpshooterrr said:
A class 10 card isn't the way to go with smartphones. Best to get a class 4.
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really, class 4, why?
too late for me, order my 32gb class 10
curious to understand this whole thing
thanks
Sharpshooterrr said:
A class 10 card isn't the way to go with smartphones. Best to get a class 4.
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I could understand saying a class 10 isn't necessary, but to say it isn't the way to go, a class 4 is best doesn't make sense. Care to explain why?
UHS-1 Cards
I just read where UHS-1 class microSD's "were made for mobile devices". Something about being specifically designed to work with those operating systems. Anyone have experience with any of those? They're awfully expensive.
If you uses a class 2 SD card with a capacity of less than 16Gb and mostly uses it to transfer small files between your phone and PC - that would be sufficiency enough.
If you intend to use a bigger card, say, 32Gb or 64Gb and you are doing a lot of transferring MP3, movies, pictures ect ... especially if moving BIG files, say, more than 1 Gb each (e.g a full MP4 movie may take up to almost 2Gb)
OR
You are frequently backup your SDCard contains and moving them between PC and phone. You will appreciates the higher speed/class of your SDCard. Higher class means higher speed in reading and writting hence saving you a lot of time.
You will not notice much differences between a class 2 and a class 10 card when using it inside your phone though.
An SDCard speeding test's result will be differ from devices and that's exactly manufacturer's stated on their package/info, but, basically you got what you paid for. As we all know, Sandisk is the most expensive card out there and there is a reason for it, just do a little research and you'll know why. Sandisk classed their card at the minimum speed that their cards are capable of, whereas other manufacturer tend to class their card at the average speed that their cards capable of. Meaning a classs 10 Samsung/PNY/Patriot card may not capable of reaching the claimed speed (because, well, results are varies on devices) and the result maybe a little lower than claimed (I've tried Samsung class 10 and PNY class 10 test and the result is somewhere more or less than 9Gb/s writting).
Anyway, a class 2 16Gb Sandisk card is good enough for an average user whereas a higher class/capacity card will increase performances for those who demand more for their task/hobbies/usage
I would agree with the post above, right on the spot. I had a 8 gb class 4, 16 gb class 4, and now 32gb class 10. Did not visibly notice speed in my phone but did notice it when transferring files. You will only benefit when transferring larger files like 1 gb or more.
I only transfer my recorded videos, pictures, mp3 and that's it. I think i once transferred a movie or two.
What would have taken me 1 hr on 16 gb class 4 took me 20 - 30 min on my patriot 32 gb class 10. No problems on it since nov so far.
Sent from my HTC Amaze 4G using xda premium
Sharpshooterrr said:
A class 10 card isn't the way to go with smartphones. Best to get a class 4.
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I have a class 4 card and the video is choppy when using HD recording. It can't write the larger amount of data fast enough.
A class 10 FTW
marleyfan61 said:
I could understand saying a class 10 isn't necessary, but to say it isn't the way to go, a class 4 is best doesn't make sense. Care to explain why?
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http://www.xda-developers.com/android/32-gb-micro-sd-analysis-speed-test/
anything over class 4 sacrafices random read/write speeds...meaning, just to write faster the data is more fragmented. Over time, the speed becomes slower and the table used to keep track of data must access parts of the fragments that are free...this reduces performance in higher class cards...if you look at Sandisk they their class two performs way above the minimum write speed, almost double...I always buy sandisk...nothing else...their quality is unmatched...they are the pioneers...A class 4 or class 6 sandisk would outperform many of the class 10's that people are buying right now.
Sometimes as Binary's card has, they lose integrity because of this reason...the index becomes messed up and the data becomes lost eaiser in higher class SD cards and lower quality SD cards...I believe Sandisk tries to minimize this even in their higher speed cards...
---------- Post added at 05:56 AM ---------- Previous post was at 05:34 AM ----------
If you guys take a look at the bitrate of the 1080p video and also add the audio bit rate it doesn't even come close to being 2 MB/s write speed which is a class 2 SD card...the highest bitrate for video I got was 11182 (kilobits per second) = 1.36499023 megabytes per second...add the 127kbps of sound and you barely have 1.4 MB/s write speed needed for the HD video recorded by our amaze...hope this clears things up.
Hi all,
I have the 10.1 2014 tab pro and I want to get a new SD card. I know from my brief reading through these forums that not all SD cards will work and I dont know enough to really understand what is what (like what does "SDHC Tf Class 10" mean?). If anyone knows what it is that I need to look for before buying one so that it will work fine with my tablet please post here.
ps I am using these primarily to store books and documents, not videos or games or anything that really takes a massive workload or speed requirement.
pps Im not sure if this matters, but I am running stock unrooted
TIA
Most any newly purchased MicroSD card should do. What did you read won't work? Below Class 10 cards might not work for some high speed functions (like video), but I believe all should work for casual use like you describe.
SDHC versus SDXC mainly refers to the capacity of the card, which you are probably going to be looking at separately (in GB) anyway, so it really doesn't matter. Basically, the original SD standard (also called SDSC) was limited to 2 (4?) GB. SDHC increased the capacity up to 32 GB, and anything higher than that is SDXC by definition. There are some other minor differences, but probably nothing you really need to worry much about.
Class (8, 10, etc.) refers to the read/write speed; but you may also see a UHS speed classification (U1, U3) also. Even though you are not talking about high speed demand tasks, I'd still tend toward Class 10 or U1 cards. Just in case you change your mind about what you want to save to the card; and many cards meet Class 10 or U1, anyway. For the few cards that you can find with lower speed class, you might save $10, so its probably not even worth it to consider lower speed class cards.
The following Wiki articles goes into a lot more detail about the specs: http://en.wikipedia.org/wiki/Secure_Digital
Out of all this, I'd be more worried about brand, or getting a counterfeit product. Some cheap or off-brand cards seem to fail more frequently than the big names. Folks all have their favorites, and may argue that you are just paying more for the brand. But I've bought several Sandisk cards, and never had any issues (and heard similar from other users on XDA).
I'd also stick to a reputable seller (Newegg, Amazon, etc.) as places like eBay are awash with counterfeit SD cards. Its so easy to relabel a card as a higher capacity (i. e. take a 32 GB card and label it as 128 GB, etc.) and even spoof the device to read it as the "fake" capacity, than charge much more $$$.
I am using one of these on my TabPRO:
http://www.amazon.co.uk/Samsung-MicroSDHC-Memory-without-adapter/dp/B00AYC6V2U
Works fine on all my Android devices.
And to really leverage it outside of Google Apps and pre-installed items you need to root and enable write to the SD card, unfortunately. (Unless I'm missing something.)
Thanks, I really appreciate that info on what all those terms mean. However, right now I am using a 32gb Sandisk ultra, and my data keeps getting corrupted, apps cant find it, showing up empty on every file explorer I try.... Therefore I thought since Sandisk is legit (I bought it at costco so its real Sandisk) I figured there must be some issue with the type of card.
pie_are_squared said:
Thanks, I really appreciate that info on what all those terms mean. However, right now I am using a 32gb Sandisk ultra, and my data keeps getting corrupted, apps cant find it, showing up empty on every file explorer I try.... Therefore I thought since Sandisk is legit (I bought it at costco so its real Sandisk) I figured there must be some issue with the type of card.
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I had similar issues with a genuine SanDisk card in my S3 (couldn't access it in recovery either), just showed a bunch random characters instead of file names etc), swapped it to a different brand (I got a genuine Sammy one because it was a bargain at the time) and that solved the problem....
So I am switching from iPhone to S8 and I am looking for SD cards to buy. The last one I bought was Class 10 (U1) like 8 years ago. It appears there are some new standards which go upto UHS-III and boast solid speeds (U3). However, it also looks like they are aimed at video recording (GoPro/dones) use.
Do any of these advanced cards (U3) offer significant speed improvement in a smartphone like Galaxy S8 or should I just stick to U1?
What do you plan on putting on the sdcard? With my samsung evo+ card 80read/20write the gallery thumbnail loading speeds are dog slow. If you're just going to put miscellaneous stuff any card will do, 64gb of storage should be enough.
Damn thats slow... I do plan to use it for occasionally transferring movies, etc. but I am just not a fan of lags/slow loading like in your case which is why I was considering the advanced one. But if that's the general case then I guess an upgrade might be worth it :/
Thumbnail loading isnt really a factor of the memory card.. My Note 5 some gallery thumbnails NEVER load, and most others take a while, and thats all from internal storage. EVO+ cards in phones are generally great and shouldnt give any noticeable lag on top of any lag the phone/app itself shows. The biggest thing youll notice between cards is, obviously, transfer rates. If you will be copying data to/from the phone from/to another device, a good quality high-speed card makes a world of difference. anything with a real 80MB/s read speed will be fine, just make sure you arent getting a clone, so doublecheck who the seller is if ordering from Amazon, and to be safe DO NOT order from eBay.
Yashraj said:
Damn thats slow... I do plan to use it for occasionally transferring movies, etc. but I am just not a fan of lags/slow loading like in your case which is why I was considering the advanced one. But if that's the general case then I guess an upgrade might be worth it :/
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For movies you should be fine, for me its loading a 1000 thumbnails that's the slow part, once they're loaded everything is fine. But from time to time it has to reload the thumbnails and its somewhat annoying.
There is an article somwhere floating around from last week on what cards to use etc.
If you use for photos and 4k vid etc the faster the better basically.
I think the more relevant question/answer here is whether the phones will support UHS-II and UHS-III. A few people have been asking that and I have not yet seen an answer. Since II and III have an extra set of pins, I would imagine it requires the host device to specifically support it by being able to use those extra pins. *If* they are backwards compatible (I don't know), then the cards might work anyway but would work at slow speed if the device doesn't support II or III and be a waste of money (obviously if not backwards compatible then it wouldnt work at all).
I still haven't seen an answer yet and as always samsung's specs dont tell you anything. We probably need someone with one of the faster cards and an S8 to try it out with A1 benchmark and see what speeds they get.
I don't think it supports UHS II or 3. I read somewhere that it supports UFS, which is Samsung's own higher speed format, which I don't think is as backwards compatible.
UHS I cards also have their own speed classes, U1 and U3 currently I think. U3 just guarantees higher sustained write speed (30MBps,) which is well within the UHS I maximum transfer speed.
If you're confused, the UHS class is the interface speed. The U1 or U3 are the minimum speed of the specific card. UHS I max speed is a little over 100MBps iirc.