Develop Bugs

upgrade from microSD Class4 to Class6

Hello,
I have a 4gb Class 4 microsd for my Cruise,
considering getting a 8gb Class 6.
Has anybody tested both of these speeds to see if there are any difference on read/write performances??
thanks a lot..
in.

inthemerde said:
Hello,
I have a 4gb Class 4 microsd for my Cruise,
considering getting a 8gb Class 6.
Has anybody tested both of these speeds to see if there are any difference on read/write performances??
thanks a lot..
in.
Click to expand...
Click to collapse
not sure but i think power consumption is also a concern. i understand that 4vs6 is about a 2MBps difference, however i think class 6 draws more power. anyone care to comment?

m.carroll said:
not sure but i think power consumption is also a concern. i understand that 4vs6 is about a 2MBps difference, however i think class 6 draws more power. anyone care to comment?
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Click to collapse
Thats really not woth anything. if you are considering upgrading because of speed, then look at the specs not the class. class just says what minimal speed it should have.
so class 4 = 4MB class 6=6MB. but there are much faster cards out there. even before those class 6 came out. You could go and buy the
"SanDisk Secure Digital High Capacity Extreme III 8GB"
it has around 20MB speed.

Raziel1 said:
Thats really not woth anything. if you are considering upgrading because of speed, then look at the specs not the class. class just says what minimal speed it should have.
so class 4 = 4MB class 6=6MB. but there are much faster cards out there. even before those class 6 came out. You could go and buy the
"SanDisk Secure Digital High Capacity Extreme III 8GB"
it has around 20MB speed.
Click to expand...
Click to collapse
Obviously I m for the speed difference. But I think you r missing a point here, I m talking about a microSD (class 2,4,6). the one u r referring to is a normal size SDHC card.
Yes, the power comsumption might be a slight problem, but I can cope with that, I m interested in faster transfer rates.
Any other ideas folks?

inthemerde said:
Obviously I m for the speed difference. But I think you r missing a point here, I m talking about a microSD (class 2,4,6). the one u r referring to is a normal size SDHC card.
Yes, the power comsumption might be a slight problem, but I can cope with that, I m interested in faster transfer rates.
Any other ideas folks?
Click to expand...
Click to collapse
i your right, i didn't see that. but still, you should take a look at the extreme series of Sandisk. they have got the fastest cards out there

[Q] Class 2? Class 10?

So I'm looking for SD cards for my vibrant. I'm wondering if I should be shelling out 100$ for a 16 GB Class 10 card or get the class 2 32 GB for the same price. Does anyone know if the phone might somehow be limited to certain file transfer speeds when connected via USB? I do intend to use the card for video and have all my apps on it. Thoughts?

From wikipedia:
The following are the ratings of some currently available cards:
Class 2: 16 Mbit/s (2 MB/s)
Class 4: 32 Mbit/s (4 MB/s)
Class 6: 48 Mbit/s (6 MB/s)
Class 10: 80 Mbit/s (10 MB/s)
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Click to collapse
You might compromise and look for a class 6 -- i've seen a lot more class 6's than 10's so you might get a much better value from a class 6 purchase -- unless you need/want the fastest possible.

Lets just say I survived for a couple of years or whatever the time frame was running my apps off my G1 on a Class 6 card just fine.
Avatar runs fine on my SD card so I'd guess at least whatever that is if you are running video.

Thanks for the input, anyone actually have a 10 that they are using? A 6 is a viable option...
Sent from my Vibrant using XDA App

Class 4 is plenty fast. Class 10 imo for this phone is a waste of money. I got a class 4 16GB for $32.99 last weekend.

Go for a class 6, 10 is overkill and really intended for mass writes in the form of very high quality video or photos in quick succession.
~ infinityv ~

i have a 32 gb class2 and it plays my 720p .mkv videos just fine

Not all micro SD cards are made the same even if they say they are a given class. Stay away from eBay there are cases where people modify the firmware of the card and you get a card that is actually smaller or slower.
The best cards are name brands like Sandisk or Lexar. Transcend is also a very good brand and the tend to mark their card such that they always meet the spec but often read at higher speeds. Kingston is the name brand card that I have seen so far, but reviews on Newegg indicate that it's R/W performance isn't class 10 (<10MB/s). Some vendors interpret the class spec such that they say cards are class X if their peak read speed is X instead of their lowest R/W speed should not go below X.
I'd recommend getting a class 6 Transcend card (lifetime warranty). The sweet spot right now is 8GB class 6 for ~$20. Their 16GB is like ~$75 on Amazon.
Class 6 is good if you plan to run apps or put extended partitions / swap on it. That is what I did with my old G1. It is also a safe bet if your planning to record at 720p.
If you just need space for playing movies and music you can go for the cheaper 32GB cards. I'd pick a class 4 to be safe if your doing HD movies.

When buying microsd does class matter much?

I know speeds are:
Class 4 - Minimum of 4 MB/s performance.
Class 6 - Minimum of 6 MB/s performance.
Class 10 - Minimum of 10 MB/s performance.
Can the Galaxy S even get up to class 10 if I go that route?

Yes, it matters a buttload.
Yes the Vibrant can make full use of the fastest chips out there.
Spend a few dollars more at Newegg and get a good chip from a known maker (Crucial, PNY, Micron, etc). The stuff is pretty cheap anyways....worth a few bucks just for piece of mind.
http://www.newegg.com/Product/Produ...00007962 600006209&IsNodeId=1&name=Micro SDHC
I'd suggest staying clear of Kingston and *possibly* Patriot.
I've nver seen Kingston stuff work as advertised and Patriot is a hit or miss at best.

Agree with n2ishun
I agree withn2ishun
Crucial and the other he mentioned are way more ereliable and have a better burst capacity (ability to write for shot periods of time faster than normal benchmark).
SD Memory Card basic breakout these are just averages i have in my phone a 16 gig card that claims 20+mb transfer rate never checked it but it is fast
Speed Class -2 Normal Bus I/F SD, miniSD, microSD
micro SDXC data rate less than 3 mb per sec
Speed Class - 4 6 HD ~ Full HD video recording above less than 7 mb per sec
Speed Class - 10 High Speed Bus I/F Full HD video recording 10 Greater than 10 mb per sec
UHS Speed Class 1 UHS-I Bus I/F HD TV Real time recording (only available on bigger cards)

micro sd card advice (manufacturer advice)
n2ishun said:
Spend a few dollars more at Newegg and get a good chip from a known maker (Crucial, PNY, Micron, etc). The stuff is pretty cheap anyways....worth a few bucks just for piece of mind.
I'd suggest staying clear of Kingston and *possibly* Patriot.
I've nver seen Kingston stuff work as advertised and Patriot is a hit or miss at best.
Click to expand...
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I dont know much about phone memory. i'll be getting my first smart phone this week (vibrant). I followed the link and the only company you had listed that i saw was PNY and they only sold cards at class 4 speeds. So besides kingston and patriot are the other's ok? Centon had a few class 6 cards that i was looking at. Or perhaps i should be asking are there any other companies i should stay away from?
thanks in advance

A lot of brands are okay. Well, that is if you buy it from a legit retailer and not from ebay where there is a chance for you to get a fake one.
Sandisk, PNY, Kingston, Adata, Transcend (I have a class 6 one), Crucial, and etc. They are all about the same. Go to Newegg for reviews.

Ah ok.
thanks alot.
Rodrigo

dont forget about meritline.com.
i get all my sd cards from there.

It only matters if you're impatient.

dezvous said:
It only matters if you're impatient.
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Click to collapse
I wouldn't say "impatient" but sometimes we have better things to do than sit there and wait for a file to finish transferring. Especially big files.

Usually files don't really get big enough on phones for 4mbs to be a huge problem.
But I'm not going to argue with you, the faster the better definitely. The good thing is there usually isn't a big difference in price between the different classes if you're shopping in the right places either.

the stock card is a class 4. I have an 8GB class 6 from my G1 days when we were doing 3 partitions on one card (crazy to me now). Does it matter? Yeah... Is it worth spending a lot of money on? Matter of opinion... how much are you using the sd card for read/write? I use the internal memory most.

I can see speed being an issue if you're taking a lot of pictures and video and saving to SD card. I usually use my external just for music, so Class 2 is fine for that (still, wouldn't turn down a Class 6 card if the cost differential were slight).

[Q] what SD Card class is best?

Hello,
My mSD card just died on me, I had 16gb class 2, so I have decided to buy a new one, so my question would be, which CLASS would be the best, and full usable on phone. I mean, if I'll get Class6, will I use the full potential of it on my phone? Or would Class4 be good enough? I am using A2SD, so the speed of the card is essencial for me, but I dont want to buy Class8 if I wont be able to use it on full potential.
thanks for help

I am using the " Transcend microSDHC 8GB Class 6" and it works pretty fast.
I think it's a big difference with a class2 SD Card.

Class 6 is the highest a MicroSD card can go. There is a class 10 but that's for SDXC cards for use with HD video recording etc.

appox said:
Class 6 is the highest a MicroSD card can go. There is a class 10 but that's for SDXC cards for use with HD video recording etc.
Click to expand...
Click to collapse
Thanks, didnt know this, so Class6 will be fully used by Desire?

appox said:
Class 6 is the highest a MicroSD card can go. There is a class 10 but that's for SDXC cards for use with HD video recording etc.
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Click to collapse
I'm using a 16gb class 10...................fast

Class 10 cards are really expensive most time. I also heard that sometimes classes don't matter. If you are using a class 4 (high quality) and a class 6 (low quality) the class 4 would be faster. But it's not always this situation.

mrbluesman said:
I'm using a 16gb class 10...................fast
Click to expand...
Click to collapse
Is that a MicroSD card or Micro SDXC card?

Transcend 8 GB Class 6 ordered off amazon for 10£, can be locked, thanks

Look at my sig for a pictural definition of what i use

Speed classes
I bought a class 6 MicroSD card, because the stock SD was defective. It is a huge leap forward!
Class 2 = 13x rating = Read (Mbit) 16.0 / Write (Mbit) 16.0 = Like 2MB min. R/W
Class 4 = 26x rating = Read (Mbit) 32.0 / Write (Mbit) 32.0 = Like 4MB min. R/W
Class 6 = 40x rating = Read (Mbit) 48.0 / Write (Mbit) 48.0 = Like 8MB min. R/W
Class 10 =66x rating = Read (Mbit) 80.0 / Write (Mbit) 32.0 = Like 10MB min. R/W
So, the x rating is equal to 1.2Mb/s (Like the standard CD-rom speed)

Charlesnasi said:
I bought a class 6 MicroSD card, because the stock SD was defective. It is a huge leap forward!
Class 2 = 13x rating = Read (Mbit) 16.0 / Write (Mbit) 16.0 = Like 2MB min. R/W
Class 4 = 26x rating = Read (Mbit) 32.0 / Write (Mbit) 32.0 = Like 4MB min. R/W
Class 6 = 40x rating = Read (Mbit) 48.0 / Write (Mbit) 48.0 = Like 8MB min. R/W
Class 10 =66x rating = Read (Mbit) 80.0 / Write (Mbit) 32.0 = Like 10MB min. R/W
So, the x rating is equal to 1.2Mb/s (Like the standard CD-rom speed)
Click to expand...
Click to collapse
The question was actualy, if the Desire CAN use those speeds, I mean, can my Desire be writing 6MBps? or can it read same speed as the best SD card?

appox said:
Is that a MicroSD card or Micro SDXC card?
Click to expand...
Click to collapse
micro sdhc, ebay, 27 quid

Zheiko said:
Transcend 8 GB Class 6 ordered off amazon for 10£, can be locked, thanks
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Click to collapse
i've bought two of them off amazon, both haven't lasted 3 months.
Wife's htc stock (sandisk class 4 8gb) over two year old is still good. Heck, she used it with her touch hd.

gascanieto said:
i've bought two of them off amazon, both haven't lasted 3 months.
Wife's htc stock (sandisk class 4 8gb) over two year old is still good. Heck, she used it with her touch hd.
Click to expand...
Click to collapse
Honestly, I hope you are more than just wrong... the feedbacks on this were 4 1/2 stars there, so I guessed I cannot go wrong... well, I will see

is there a software/app to check speedness of my SdCard?

Zheiko said:
The question was actualy, if the Desire CAN use those speeds, I mean, can my Desire be writing 6MBps? or can it read same speed as the best SD card?
Click to expand...
Click to collapse
Yes, the Desire can use the speeds till Class 10 (And maybe faster) WITH big files. A time back I red a comparison and difference between Class 4 and 10 was with largest file almost 10MB+ faster (for the Class10) But with small files the classes doesn't really matter, 4 or 10 Class cards will be even slow because the Desire HW is the bottleneck!

Charlesnasi said:
Yes, the Desire can use the speeds till Class 10 (And maybe faster) WITH big files. A time back I red a comparison and difference between Class 4 and 10 was with largest file almost 10MB+ faster (for the Class10) But with small files the classes doesn't really matter, 4 or 10 Class cards will be even slow because the Desire HW is the bottleneck!
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Click to collapse
exactly what I needed, so basicaly, for a2ext it doesnt really matters, and the apps will be loaded equally from class2 or class6, since those are very small files, right?

to my experience, d2ext has shown quite improvement over class 6 card

Get a good quality, high capacity 16GB +, class 4 card. that should do for you for a good while.

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

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

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

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

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

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

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

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

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

daveybaby said:
Here's the thing: the class of an SD card only defines how fast you can *write* to it.
Click to expand...
Click to collapse
That's incorrect - the class rating is a guarantee of both read and write speeds.
daveybaby said:
The read speeds of all cards tend to be the same regardless of class.
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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.
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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.
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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.
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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