Related
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.
Where is the best/cheapest place to get SD cards?
I am thinking about getting a 32gb card for all my music etc..
And...
Is there a big difference between the "classes"?
http://lmgtfy.com/?q=MicroSD+card+classes
you got two options when it comes to 32gb cards, $80 for a class 2, or $150 for a class 4. Video over 2mbps may studder on class 2 cards.
Kingston introduces Class 4 32GB microSDHC card, charges dearly for the speed
16gb class 4 @ frys for 32$.
Best deal I've seen..
Sent from my SGH-T959 using XDA App
Class? Kinda, if you have an 8gig at class 6 and you move up to a 16 gig running at class 6 the larger drive will be slower. The reason being you need more voltage for 16 gig to reach class 6 then an 8gig. The phone won't provide it though since its voltage is regulated so not to incur more heat on the phone and damage the internal hardware. With 32gig being twice the capacity its hard to say how many volts it would need to hit class 4 speeds but its probably best to run benchmarks to see
psychoace said:
Class? Kinda, if you have an 8gig at class 6 and you move up to a 16 gig running at class 6 the larger drive will be slower. The reason being you need more voltage for 16 gig to reach class 6 then an 8gig. The phone won't provide it though since its voltage is regulated so not to incur more heat on the phone and damage the internal hardware. With 32gig being twice the capacity its hard to say how many volts it would need to hit class 4 speeds but its probably best to run benchmarks to see
Click to expand...
Click to collapse
Nice info, did not know that...
Sent from my SGH-T959 using XDA App
The K-Zoo Kid said:
Where is the best/cheapest place to get SD cards
I am thinking about getting a 32gb card for all my music etc..
And...
Is there a big difference between the "classes"?
Click to expand...
Click to collapse
www.supermediastore.com is my favorite place. They are having a deal right now for a Class 10 32GB for $56.77 (click link) AData and Transcend have pretty much done me right so far.
psychoace said:
Class? Kinda, if you have an 8gig at class 6 and you move up to a 16 gig running at class 6 the larger drive will be slower. The reason being you need more voltage for 16 gig to reach class 6 then an 8gig. The phone won't provide it though since its voltage is regulated so not to incur more heat on the phone and damage the internal hardware. With 32gig being twice the capacity its hard to say how many volts it would need to hit class 4 speeds but its probably best to run benchmarks to see
Click to expand...
Click to collapse
I cant agree. Micro SD cards have a 3.3V standard, most are pretty close to the same amperage draw also. If you follow most memory trends the larger the chips and capacity gets, the less power required and usually smaller build technology. So while in theory I think larger would equal more power, I dont actually think thats true. I think newer, larger cards use less power than older smaller ones. Even if they are much faster. Just my opinion, not fact.
So my advice is to get the largest and fastest card you can. Have yet to have any adverse effects on any phone.
techboydino said:
www.supermediastore.com is my favorite place. They are having a deal right now for a Class 10 32GB for $56.77 (click link) AData and Transcend have pretty much done me right so far.
Click to expand...
Click to collapse
That's for a regular SD card. There's no such thing as a Class 10 32GB Micro SD. Not yet, anyway.
psychoace said:
Class? Kinda, if you have an 8gig at class 6 and you move up to a 16 gig running at class 6 the larger drive will be slower. The reason being you need more voltage for 16 gig to reach class 6 then an 8gig. The phone won't provide it though since its voltage is regulated so not to incur more heat on the phone and damage the internal hardware. With 32gig being twice the capacity its hard to say how many volts it would need to hit class 4 speeds but its probably best to run benchmarks to see
Click to expand...
Click to collapse
So my phone will overheat if i dont get a high enough class?
I guess my real question is, does it matter what class i have if i will strictly be using the card for music? I use my internal for everything else..
The K-Zoo Kid said:
So my phone will overheat if i dont get a high enough class?
I guess my real question is, does it matter what class i have if i will strictly be using the card for music? I use my internal for everything else..
Click to expand...
Click to collapse
Don't worry about the card overheating. The minor changes in voltage mean practically nothing to us.
If all you are storing is music (like myself) then just get a class 2. This one from Verizon is probably the cheapest one you're going to find. Basically anything cheaper (like from eBay or Craigslist) is most likely a scam.
gravis86 said:
Don't worry about the card overheating. The minor changes in voltage mean practically nothing to us.
If all you are storing is music (like myself) then just get a class 2. This one from Verizon is probably the cheapest one you're going to find. Basically anything cheaper (like from eBay or Craigslist) is most likely a scam.
Click to expand...
Click to collapse
Thanks bro.
Kubernetes said:
That's for a regular SD card. There's no such thing as a Class 10 32GB Micro SD. Not yet, anyway.
Click to expand...
Click to collapse
Good catch, jumped the gun on that one. But....there is certainly CL10 Micro SD's thats just not one of them. Do a quick Google search and youll find some for sale. Price is still pretty high though.
The K-Zoo Kid said:
So my phone will overheat if i dont get a high enough class?
I guess my real question is, does it matter what class i have if i will strictly be using the card for music? I use my internal for everything else..
Click to expand...
Click to collapse
No I'm saying your phone's microsd card will run as fast as a class 2 card if it's actually a class 4. I said the voltage is regulated that means it wont go over a predetermined amount. That is why the cards go slower and why they don't overheat.
Outside of Ebay, the best price I've seen for Class 2 32GB microSDHC cards is at
http://www.datamemorysystems.com/_memory-information/DM55_0981-2A.asp for a Transcend card.
Best price for Kingston's Class 4 32GB card is like $100.
Kingston and Transcend have just entered the 32GB microSDHC market this month joining SanDisk, so prices have dropped a bit and may drop more in the future.
psychoace said:
Class? Kinda, if you have an 8gig at class 6 and you move up to a 16 gig running at class 6 the larger drive will be slower. The reason being you need more voltage for 16 gig to reach class 6 then an 8gig. The phone won't provide it though since its voltage is regulated so not to incur more heat on the phone and damage the internal hardware. With 32gig being twice the capacity its hard to say how many volts it would need to hit class 4 speeds but its probably best to run benchmarks to see
Click to expand...
Click to collapse
So you're familiar with ohms law....or at least you'd say so ?
You do know that the voltage paths and the data paths are on different pins ..... right ?
Your post is one of the most ill-informed I've ever heard.
http://en.wikipedia.org/wiki/Secure_Digital#SDHC
Go there, learn something.
Voltage has NOTHING to do with read speed or data capacity.
They all run the same voltage, and *gasp* the same amperage.
I guess since volts x amps = watts....they must run the same wattage too
BTW, all SDHC chips are required to run under a very tight specification and they have to be licensed to run in that spec.....so there is no room for deviation in the voltage arena.
Here, since you are mis-informed of the class specs too (jeebus!).
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), and it measures the minimum sustained write speeds for a card in a fragmented state [10].
The following are the ratings of some currently available cards: [11]
Class 0 - These cards do not specify performance, which includes all legacy cards prior to class specifications.
Class 2 - Minimum of 2 MB/s performance. Lowest speed for SDHC cards.
Class 4 - Minimum of 4 MB/s performance.
Class 6 - Minimum of 6 MB/s performance.
Class 10 - Minimum of 10 MB/s performance.
Click to expand...
Click to collapse
n2ishun said:
Here, since you are mis-informed of the class specs too (jeebus!).
Click to expand...
Click to collapse
So your saying the card determines speed always? Your saying there will be no bottleneck ever? So no matter what, your card will run at peak speeds at all times on any device? Your saying that flash memory can do the impossible? Cpu's and ram need certain voltages to run at at top speeds. Your saying that no matter the voltage the memory will run at rated speeds at all times. I'm sorry but your wrong. Flash memory is like any other computer part. In order for it to reach optimal speed it needs current. If you don't provide enough voltage to ram it wont run at the rated speed it's setup for, same goes for cpu's/gpu's/ssd's and everything else. If you look here you will see that microsd cards vary in voltage from 2.7v's to 3.6v
http://www.sdcard.org/developers/tech/sdhc/
That means certain sd cards could use more voltage for different reason. 1 being they are rated at higher class of speeds 2. they need it because they are running a more condensed memory package. In order for class 6 cards to reach those speeds it needs enough electricity to run. Just like cpu/ram if there is not enough voltage it will run at slower speeds. With cpu/ram though you pick the speeds before hand. With sd memory they decided on a little more looser scheme. If the card gets enough juice it will run at it's optimal speed but if it doesn't it will have to drop to a slower speed. This is all done automatically so you don't have to worry about it since you might throw this memory in multiple devices and to setup multiple devices for it would be a pain. So yes I understand there is a difference between data paths and voltage paths I do know that voltage paths supply the power to run the data paths. With less power running the data paths the slower it will go. So with phones manufacturers lowering said voltage to better optimize there phones for power consumption and heat reduction it shouldn't be to hard to understand that these cards wont run at there rated speeds in said device. Phone manufactures are going to take the middle road and not allow 3.6v's to hit the microsd slot. That will cause to much heat and during stress tests they don't want to scrap a phone just because it can't handle the voltage needed to run cards at speeds most people wont notice. Most phones run at 3.3v's or less on there microsd slot. If your card needs 3.6v it wont just say "can't accept card" it will run it but it wont be able to provide enough juice to support it's rated speed.
If you still don't believe that devices cause bottlenecks run this test. All you need is 3 things (outside of your computer of course) a camera, memory for said camera (be it compact flash/sd/sdhc/microsd/etc) and a USB2 memory card reader. If you don't have these see if you can find someone who does or have them run these tests. Ok now either throw 100mb of files on the card or find a group of photos totaling near 100mb's. Now plug in the camera and copy those files to your desktop. See how long it takes (you don't need a stop watch cause the difference is not subtle) to complete the transfer and note the rated transfer speed and time. Now delete those files off your desktop and run again but this time with the card inserted into your media card reader. Jot down the rate of speed and time. You will notice a much quicker transfer with the media card read then the camera. The reason being as mentioned many times is that they regulate voltage on devices. With a media card reader it doesn't need to be regulated cause it's not setup to worry about battery drains and it doesn't need to worry about getting to hot. Unless you can figure out another reason why the camera would slow down the speed of transfer I would like to know.
I have a 32GB class 2 and it runs just fine for videos. I can play Avatar with no hiccups on it at all.
techboydino said:
Good catch, jumped the gun on that one. But....there is certainly CL10 Micro SD's thats just not one of them. Do a quick Google search and youll find some for sale. Price is still pretty high though.
Click to expand...
Click to collapse
No, the link you showed is a 16GB. Again, there is no such thing as a Class 10 32GB Micro SD card at this time. Sandisk has a Class 2 and Kingston a Class 4, but nothing faster is out on the market right now.
blah blah, whatever
Learn what voltage is
Learn what current is
You're talking out of serious lack of knowledge.
That phone you are speaking of IS NOT a desktop computer, the devices are not singular and replaceable, let alone capable of a variance of factors.
You simply do not go into the bios and tweak the settings on a phone.
If the SD card runs or not is the factor, *voltage* (ahem) does not change, it is STATIC!
I guess YOU could always slap a RAID card in it and SLI some video chips....
But back in the real world.....
Can someone do that test? Will a Class 6 card work at Class 6 speeds in the phone? I would think so since cards are classified based on minimum sustained transfer... even if a particular card can get higher output in certain applications, it shouldn't fall below the minimum class rating, right?
Yeah. So obviously other benchmarks for MicroSDHC cards on other phones won't be suitable due to hardware differences. The speed also can't be based on the cards class either, because again there are hardware differences and card manufacture quality differences. So I'm going to start by posting my card and results with SD Card Speed Tester from the market. I thought it would better to test the card on the phone itself, as that's where we will be using the phone the most.
I have not rooted or altered my Evo software in any way, if it matters.
Hardware revision 003.
Sofware 3.29.651.5
My card is a Kingston 4GB Class 4 MicroSDHC Model SDC4/4GB Amazon
SD Card Speed Tester Results 6 Tests(1-3MB Buffer) 2 each buffer size.:
1MB buffer:
Test 1: ------
Write 4MB/s
Read 10MB/s
Test 2: ------
Write 5MB/s
Read 10MB/s
2MB buffer:
Test 1: -----
Write 5MB/s
Read 10MB/s
Test 2: -----
Write 5MB/s
Read 10MB/s
3MB buffer:
Test 1: -----
Write 4MB/s
Read 10MB/s
Test 2:-----
Write 5MB/s
Read 11MB/s
Consistent speeds, but I want faster. Post your card model and results with SD Card Speed Tester app on the Evo 4G.
weehooherod said:
KOMPUTERBAY 16gb Class 6 Card
Write: 7 MB/s consistent
Read: 11 MB/s consistent
Testing with "h2testw" on my computer through a micro sd to sd adapter.
Only $47 with shipping too!
http://www.amazon.com/KOMPUTERBAY-m...dapter/dp/B003O996G8/ref=cm_cr_pr_product_top
Edit: Just tested with the SD Card Speed Test app on my Evo and got 4 MB/s Write and 13 MB/s Read. I don't trust that app though because there are too many factors affecting the results. I ALWAYS get higher scores right after a reboot, on airplane mode, all apps killed, super overclocked. Testing from a computer will give you more accurate results.
Click to expand...
Click to collapse
computer speed might also be a factor.
Try doing this test on difference computers if you can, I can test on 3 computers of varying speeds.
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
Can anyone comment yet on the speeds they are getting with their internal microsd cards for read and write?
I would like to see if it is worth splashing out on an expensive high speed card, or because it is running USB2 that in real terms it is crippled to about 20MBps read/write. It would be a pitty if the speeds are crappy, as samsung is making some pretty sweet microsd cards these days.
Regards
hardjards said:
Can anyone comment yet on the speeds they are getting with their internal microsd cards for read and write?
I would like to see if it is worth splashing out on an expensive high speed card, or because it is running USB2 that in real terms it is crippled to about 20MBps read/write. It would be a pitty if the speeds are crappy, as samsung is making some pretty sweet microsd cards these days.
Click to expand...
Click to collapse
Afaik, sd card doesn't use the usb bus.
I have a cheap 64GB microsd and it gives 40/18mbps on the 8.4 pro on a1 sd bench tests
ssuper2k said:
Afaik, sd card doesn't use the usb bus.
I have a cheap 64GB microsd and it gives 40/18mbps on the 8.4 pro on a1 sd bench tests
Click to expand...
Click to collapse
Thank you very much Ssuper2k. That is good to know if you are getting decent speeds on a cheap 64GB microsd. Anyone got any high rated SD cards share any light on what it tops out at ?
Thanks again.
hardjards said:
Thank you very much Ssuper2k. That is good to know if you are getting decent speeds on a cheap 64GB microsd. Anyone got any high rated SD cards share any light on what it tops out at ?
Thanks again.
Click to expand...
Click to collapse
Heres mine... Sandisk 64GB Class 10
BossJ said:
Heres mine... Sandisk 64GB Class 10
Click to expand...
Click to collapse
That is not the SD card...
My g.skill 64GB class 10 benchmarks around 44MB/sec read, 14 write. It cost $25.
Skitals said:
That is not the SD card...
My g.skill 64GB class 10 benchmarks around 44MB/sec read, 14 write. It cost $25.
Click to expand...
Click to collapse
ooops. you are right... a1 sd bench labels it wrong. It says Internal SD card as my external and my internal as my external. (Sorry)
Here's my new results - reading 40 MB/sec 14 MB/s write..
Once again - sorry about that.
Guys, when you say Class 10 you aren't really speaking to the speed of the card. There is a wide range of speeds in cards that are all rated as class 10. Samsung has some that are 90 read and 80 write for example and most only advertise as 30 read and don't even say their write. Anyone have one of Samsung's good 90/50 or 90/80 cards they have tested?
I have just benchmarked a 64GB Samsung Pro MicroSDXC card (rated at 90MB/s read, 80MB/s write). In a USB 3.0 card reader on my computer it writes at around 65MB/s average and reads at upwards of 80MB/s.
In the Tab S 8.4 (Wi-Fi only model) it benchmarks at 49.53MB/s read and 24.53MB/s write in A1 SD Bench
So what would anyone say... Is the best card for this particular device? Any recommendations?
If you're not planning on taking the MicroSD card out of the tablet in order to transfer content onto it, then you might as well just go for a mid-range card as it will be limited by USB 2.0 transfer speeds anyway. I'd say the Samsung Evo or the old Samsung Pro card would be fine depending on pricing.
I dont plan on taking it out. Since the above Benchmade had the pro at 49.53MB/s read. I feel It's just going to be overkill. Since its not getting the full 90 MB/s read 80MB/s write. I'm thinking the Evo should suffice. What are your thoughts?
I meant the old Pro model, which I think was 70MB/s Read - 20MB/s write, these can sometimes be had for similar money as the new Evo. I think you'd be fine with either of those, or even the Plus model. I think the Samsung MicroSDs are fairly reliable in general.
So nobody knows if Tab S has standard bus, high speed bus or Ultra High Speed Bus UHS-I or UHS-II?
I think that micro SD card Class 10 U3 guarantees minimum 30MB/s. So it supports even 4K recording...
But I still don't know if it is worth of a lot of money. If benchmarks are true - Tab S has UHS (your 45MB/s). If!
bus speeds
belek1979 said:
So nobody knows if Tab S has standard bus, high speed bus or Ultra High Speed Bus UHS-I or UHS-II?
I think that micro SD card Class 10 U3 guarantees minimum 30MB/s. So it supports even 4K recording...
But I still don't know if it is worth of a lot of money. If benchmarks are true - Tab S has UHS (your 45MB/s). If!
Click to expand...
Click to collapse
According to Samsung support, the Tab S micro SD speeds is limited by the USB 2.0 bus, or 60 MB/s. So that would imply UHS, though the 90MB/s cards would not get the full speed. I would like to see someone test a 90MB/s card and see what the results are. Probably just going to go with a 48MB/s card if there isn't any difference. Though I think write speeds are significantly different between the higher speed UHS-I cards and the lower speed ones (50 vs 10 MB/s write I think).
If anyone has a couple cards and a Tab S they can test with, I would love to see the results.