Develop Bugs

[Q] SD Card Class Check

I've read many threads about certain apps needing a sd card of class 6.
I am currently using one that came with my HTC desire, which is a 2gb one.
How do i check if my SD card is class 6 or not?
Thanks in advance.

It is usually written on the card you may see a number in a circle. Benchmarking apps can also help, try antutu or sd card tools from the market.
Sent from my HTC Desire using XDA App

iirc: the stock card is a class 2 card but a fast one (> cheap class 4)

Yep, the stock card is Class 2.
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- Sent via HTC Desire -

Any advice on which are the best higher class sd cards to purchase, taking into account cost, speed & reliability ?

play.com had a sale on some class 6 8gb cards. i don't know if they still do. i got mine from them.

One of compatible class 10 cards are from A-Data.

I also have class 2 4 GB card, SD tools can't detect the class and selects the "?" radio button. However the read are write speed are 23MB/s and 5.3MB/s. Is this normal?

I also have class 2 4 GB card, SD tools can't detect the class and selects the "?" radio button. However the read are write speed are 23MB/s and 5.3MB/s. Is this normal?
Click to expand...
Click to collapse
It depends on the free space on your sdcard...
I have a Lexar 32GB Class 10 and when I have free space of 20GB the read speed is cca 35MB/s and the write sp. is 10MB/s. When a 10GB free space: 25 and 8MB/s.
EDIT: Can somebody confirm that I'm right?
EDIT2: MB/s not GB/s
Sent from my HTC Desire using XDA Premium App

10GB/s? You sure that's what you wanted to write?

Terepin said:
10GB/s? You sure that's what you wanted to write?
Click to expand...
Click to collapse
Sorryy!!! MB/s for sure
Sent from my HTC Desire using XDA Premium App

To answer your question: No, those numbers are wrong. I suggest to format SD card with SDFomatter.

Whose question are you answering?

me too. Thanks in advance .

bhotey said:
Whose question are you answering?
Click to expand...
Click to collapse
Not yours.

[Q] 32gb Class 4 and Class 6 Benchmarks?

I currently have a Class 2 16gb card and would like to upgrade to a 32gb, but I would like to know if Class 6+ makes any difference on the Epic.
Currently using SD Tools I get 5.6mb/s write and 17.0mb/s read on a card formatted using 64k allocation and using the 2048kb read ahead patch.
Could someone run SD Tools with a Class 6 (or higher) and a Class 4 card?
Thanks.

tbob18 said:
I currently have a Class 2 16gb card and would like to upgrade to a 32gb, but I would like to know if Class 6+ makes any difference on the Epic.
Currently using SD Tools I get 5.6mb/s write and 17.0mb/s read on a card formatted using 64k allocation and using the 2048kb read ahead patch.
Could someone run SD Tools with a Class 6 (or higher) and a Class 4 card?
Thanks.
Click to expand...
Click to collapse
I went and bought a class 6 sdcard from "lexar". And my benchmarks using "sdcard speed" went up a good bit. But the class 6 card cost about $100, with shipp8ing and all. I heard that there's a lot of cheap quality class 6 cards out there that don't give you a increased read/write speed boost over a class 2. So be careful on what brand sdcard you buy...
I get a 12mb/s to 14mb/s write speed, and a 62mb/s read speed with my "lexar" 16gb class 6 sdcard... using 3072 cache size
Sent from my SPH-D700 using XDA App

sniperkill said:
I went and bought a class 6 sdcard from "lexar". And my benchmarks using "sdcard speed" went up a good bit. But the class 6 card cost about $100, with shipp8ing and all. I heard that there's a lot of cheap quality class 6 cards out there that don't give you a increased read/write speed boost over a class 2. So be careful on what brand sdcard you buy...
I get a 12mb/s to 14mb/s write speed, and a 62mb/s read speed with my "lexar" 16gb class 6 sdcard... using 3072 cache size
Sent from my SPH-D700 using XDA App
Click to expand...
Click to collapse
That seems very speedy for a phone. Wonder what speed a Class 4 would get.
I don't mind paying a bit more. I usually stick with name brand memory chips (sandisk, lexar, kingston, pny). I prefer Sandisk, but I've only seen class 4 32gb chips so far.

tbob18 said:
That seems very speedy for a phone. Wonder what speed a Class 4 would get.
I don't mind paying a bit more. I usually stick with name brand memory chips (sandisk, lexar, kingston, pny). I prefer Sandisk, but I've only seen class 4 32gb chips so far.
Click to expand...
Click to collapse
You probably won't find a class 6 anywhere in the stores. You gotta order them. I got mine from www.lexar.com also, I wouldn't buy from kingston, or pny. I heard they had problems with certain ones...
Sent from my SPH-D700 using XDA App

My komputer bay is 5/15 32gb
Sent from my SPH-D700 using XDA Premium App

tbob18 said:
I currently have a Class 2 16gb card and would like to upgrade to a 32gb, but I would like to know if Class 6+ makes any difference on the Epic.
Currently using SD Tools I get 5.6mb/s write and 17.0mb/s read on a card formatted using 64k allocation and using the 2048kb read ahead patch.
Could someone run SD Tools with a Class 6 (or higher) and a Class 4 card?
Thanks.
Click to expand...
Click to collapse
I get 10 write 24 read on my class 4 16gb sandisk with a 1024 patch. 1024 seems to work slightly better for my card than 2048, and definitely better than other options I've tried. That 60 read sounds a little extreme to me. Leaves me wondering how you managed to squeeze so much more out of a class 6 of similar quality brand.
Sent from my SPH-D700 using XDA Premium App

Class 10 UHS-I cards on Desire?

I am thinking of getting SanDisk 16GB Mobile Ultra Class 10 UHS-I Micro SD SDHC like that one.
I know I will not reach 10 Class speed but I need to replace my current card and this is the only thing I found from SanDisk.
Can I expect it to perform flawlessly with HTC Desire?

impactor said:
I am thinking of getting SanDisk 16GB Mobile Ultra Class 10 UHS-I Micro SD SDHC like that one.
I know I will not reach 10 Class speed but I need to replace my current card and this is the only thing I found from SanDisk.
Can I expect it to perform flawlessly with HTC Desire?
Click to expand...
Click to collapse
I am using this and works flawlessly

impactor said:
I am thinking of getting SanDisk 16GB Mobile Ultra Class 10 UHS-I Micro SD SDHC like that one.
I know I will not reach 10 Class speed but I need to replace my current card and this is the only thing I found from SanDisk.
Can I expect it to perform flawlessly with HTC Desire?
Click to expand...
Click to collapse
I am using the same card as well, and it works perfectly. With full class 10 speeds as well.

I am using this as well... No problem at all... Getting much faster speed..

Thanks all. The reason I need to change my sd card is because right now I have a Samsung 8GB Class 6 which is fast enough in transfers but slow in initialisation and newer ICS/JB roms can't even detect it.
What rom are you using with this card?

has anybody noticed a performance increase while using a UHS-I card compared to class 10 or class 6.
Desire needs sd with high IO because of the low internal memory. Now the question, which cards have higher IO? Class 6 or 10 or UHS-I?

Im using a 16 gb uhs class 10 and no issues at all
Sent from my GT-P7310 using xda app-developers app

Well, I got my own card and indeed it is working perfectly fine.
Would putting a swap partition on it decrease its lifespan noticeably?

have someone tried the 32gb class 10 version? does it work well with int2ext+ or m2sd?

impactor said:
I am thinking of getting SanDisk 16GB Mobile Ultra Class 10 UHS-I Micro SD SDHC like that one.
Click to expand...
Click to collapse
"Mobile Ultra" is class 6 and "Ultra" is class 10. I don't know if there are any other differences apart from speed.
The link you gave is actually selling an "Ultra", although the title is "Mobile Ultra"
Note, I would never buy an SD card on ebay because of the number of fakes (especially Sandisk apparently)
You can get 16GB "Mobile Ultra" on Amazon for £11.45, ie same price as ebay.
Or a 32GB "Mobile Ultra" on Amazon for £22.99
Or a 32GB "Ultra" on Amazon for £18.54
No, I don't know why the class 10 is cheaper than the class 6. However... "class 6" just means that's the minimum guaranteed speed, it might be faster.
NB from what I've read, most class 10 cards don't work on the HTC Desire at all, but some do* However I've also read that internally the Desire can't read at more than 6mb/s whatever you put in there.
*People seem to have success with ADATA 16mb class 10, but someone else said their SanDisk 10 worked, whereas others say the same card didn't work. YMMV

tobydjones said:
AFAIK "Mobile Ultra" is class 6 and "Ultra" is class 10. I don't know if there are any other differences apart from speed.
The link you gave is actually selling an "Ultra", although the title is "Mobile Ultra"
Note, I would never buy an SD card on ebay because of the number of fakes (especially Sandisk apparently)
You can get 16GB "Mobile Ultra" on Amazon for £11.45, ie same price as ebay.
Or a 32GB "Mobile Ultra" on Amazon for £22.99
Or a 32GB "Ultra" on Amazon for £18.54
No, I don't know why the class 10 is cheaper than the class 6.
However... "class 6" just means that's the minimum speed, it might be faster.
BUT from what I've read, the HTC Desire will accept a class 10 card, but only has a class 6 transfer bus, so it can't use it any faster anyway.
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Not quite right since all sandisk mobile ultra micro sd cards are UHS-1 class cards fastest cards faster than class 10.
They run at double the frequency in a UHS-1 compatible device.
Will still work in the desire just much slower. I get around class 10 speeds from my 8gb .mobile ultra
Sent from my HTC Desire using xda app-developers app

dethrat said:
Not quite right since all sandisk mobile ultra micro sd cards are UHS-1 class cards fastest cards faster than class 10.
They run at double the frequency in a UHS-1 compatible device.
Will still work in the desire just much slower. I get around class 10 speeds from my 8gb .mobile ultra
Sent from my HTC Desire using xda app-developers app
Click to expand...
Click to collapse
That's interesting. It would explain why they're more expensive than the class 10 cards. But if you look at this amazon page, it's listed as class 6, which is confusing.

All this talk about speed and class isn't worth much to any a2sd script.
Class system is about sequential speed I.e writing a large file and you'll get the class speed.
Writing loads of small files and I doubt you'll get your class speed.
Plus the apps on your ext4 partition could well be reading and writing from both you fat32 and ext4 partition on your SD card slowing the whole thing down.
Sent from my HTC Desire using xda app-developers app

dethrat said:
All this talk about speed and class isn't worth much to any a2sd script.
Class system is about sequential speed I.e writing a large file and you'll get the class speed.
Writing loads of small files and I doubt you'll get your class speed.
Plus the apps on your ext4 partition could well be reading and writing from both you fat32 and ext4 partition on your SD card slowing the whole thing down.
Sent from my HTC Desire using xda app-developers app
Click to expand...
Click to collapse
I suppose the hope is that the higher the class the higher the random read/writes as well as sequential speeds.
But the random write performance measured on Tom's Hardware isn't encouraging (November 10, 2011 so not very current unfortunately, but maybe shows that a class 4 SanDisk isn't to be sneered at)

I was using SanDisk class 4 sd card with InsertCoin-1.1.4 Rom. After upgrading sd card to Kingston class 10, it's really improved the performance of the same Rom.
Sent from my HTC Desire using xda app-developers app

Lakmal84 said:
I was using SanDisk class 4 sd card with InsertCoin-1.1.4 Rom. After upgrading sd card to Kingston class 10, it's really improved the performance of the same Rom.
Click to expand...
Click to collapse
I've just bought a SanDisk class 6 'mobile ultra' 32gb card.
Someone's posted a CDM showing a random write speed of 1.222 (!), so I'm looking forward to seeing the effect from swapping from my current 0.01 speed card!

dethrat said:
All this talk about speed and class isn't worth much to any a2sd script.
Class system is about sequential speed I.e writing a large file and you'll get the class speed.
Writing loads of small files and I doubt you'll get your class speed.
Click to expand...
Click to collapse
I started reading from the beginning wondering how long will it take for someone to point it out.
Sent from my HTC Desire using Tapatalk 2

Using the 32gb uhs-1 because of very high 4k write/read ( SDSDQU-032G-U46A) performance, some san disc class 4 cards are able for this, too. Habe never found so fast cards Form other manufactors.
Sent from my HTC Desire using xda premium

impactor said:
I am thinking of getting SanDisk 16GB Mobile Ultra Class 10 UHS-I Micro SD SDHC like that one.
I know I will not reach 10 Class speed but I need to replace my current card and this is the only thing I found from SanDisk.
Can I expect it to perform flawlessly with HTC Desire?
Click to expand...
Click to collapse
Just ordered it after reading the rest of the thread, thanks for the idéa!

[Q] sd card class 10 speed makes difference on speed of int2ext/m2sd scripts?

i have a kingston class 10 sd card but i feel it is not really a genuine class 10 card.. my speed on sd card tester(on market) is only 1.8mb/s write speed and 10.03mb/s read speed
my question is if i buy a true genuine sandisk micro sd class 10 card.. will it speed up my applications using int2ext/m2sd or any a2sd scripts? actually what is the speed of the internal memory of the htc desire?

yeahman45 said:
i have a kingston class 10 sd card but i feel it is not really a genuine class 10 card.. my speed on sd card tester(on market) is only 1.8mb/s write speed and 10.03mb/s read speed
my question is if i buy a true genuine sandisk micro sd class 10 card.. will it speed up my applications using int2ext/m2sd or any a2sd scripts? actually what is the speed of the internal memory of the htc desire?
Click to expand...
Click to collapse
I have a kingston class 10 card too. Mine writing speed is 11.6 MB/s and reading is 18.1 MB/s (measured with sd-tool app). I was using InsertCoin 1.1.4(a2sd) rom with class 4 card, after upgrading the sd card to class 10, it really improved the performance.

ok mine must be fake then! will buy a sandisk one from ebay(anyone has a good experience buying microsd on ebay.. everyone seems to say they are all fake... even the trusted buyers sell fake ones?)

AFAIK Desire supports only Class 6, so your Class 10 SD will work as 6.
You will achieve Class 10 speeds only copying with USB from PC for example.

k3lcior said:
AFAIK Desire supports only Class 6, so your Class 10 SD will work as 6.
You will achieve Class 10 speeds only copying with USB from PC for example.
Click to expand...
Click to collapse
I doubt you'd get class 10 even through the USB.
Best way to check SD card speeds is to put it in a card reader and into laptop or PC.
Checking through the HTC desire is useless as speeds can vary.
I've just tested twice with sdcard tester and got 10mbps and 3.7mbps
Sent from my HTC Desire using xda app-developers app

dethrat said:
I doubt you'd get class 10 even through the USB.
Sent from my HTC Desire using xda app-developers app
Click to expand...
Click to collapse
Yes you get full speed thru usb as it's not using Desire onboard sd controller...
If you're not getting full speed it might be ROM issue for example.

[Q] 16GB Class 10 Micro SDHC, only 2MB/s write speed

So I have this SanDisk Ultra 16GB Class 10 microSDHC Card from Best Buy, which was on sale for $20 when I bought it two months ago. Formatted the card as soon as I put it inside the phone. I started to transfer some music albums from my PC and the write speeds are very slow, averaging only 1.8 MB/s. I'm not getting anywhere near Class 10 write speeds. Don't have a USB SD card reader that supports SDHC, so I don't have the option to take it out and use the SD adapter. I tried using an SD speed increase app and changed the cache to 2048 KB, but same result. Didn't want to bring up this issue until now.
Anyone have any solutions to this? If it helps, I'm running CM 10.1 (Android 4.2.1), Nitest 12-31 kernel for CM 10.1 Preview Build.

Makes a huge difference because you will need a usb 3.0 port on your computer for that to work
Sent from my SPH-D700 using Tapatalk 2

phonehunter59 said:
Makes a huge difference because you will need a usb 3.0 port on your computer for that to work
Sent from my SPH-D700 using Tapatalk 2
Click to expand...
Click to collapse
I don't think so. My Transcend 4GB C10 and Lexar 16GB C10 are writing at 10MB/s just fine on USB 2.0 reader and ports.
Sent from HTC Incredible S @ CM10

AndyYan said:
I don't think so. My Transcend 4GB C10 and Lexar 16GB C10 are writing at 10MB/s just fine on USB 2.0 reader and ports.
Sent from HTC Incredible S @ CM10
Click to expand...
Click to collapse
I get about 6-8 MB with a class 4 on usb 2.0 ports
Sent from my SPH-D700 using Tapatalk 2

InsaneHien said:
So I have this SanDisk Ultra 16GB Class 10 microSDHC Card from Best Buy, which was on sale for $20 when I bought it two months ago. Formatted the card as soon as I put it inside the phone. I started to transfer some music albums from my PC and the write speeds are very slow, averaging only 1.8 MB/s. I'm not getting anywhere near Class 10 write speeds. Don't have a USB SD card reader that supports SDHC, so I don't have the option to take it out and use the SD adapter. I tried using an SD speed increase app and changed the cache to 2048 KB, but same result. Didn't want to bring up this issue until now.
Anyone have any solutions to this? If it helps, I'm running CM 10.1 (Android 4.2.1), Nitest 12-31 kernel for CM 10.1 Preview Build.
Click to expand...
Click to collapse
My Take...
1.Transferring multiple small files will always be slower in transferring speed than a single big file.
2. Using your phone as an alternative to sd card reader will be a lot slower at transferring files to your PC. I always prefer to take out the memory card out of my phone and connect it with an sd card reader instead of attaching a direct usb cable to my phone.
3. install "SD Card Tester" from the play store, try to close all the other open apps and test your memory card with it within your phone. My results with my Micro Center branded class 10 card were ~6MB for Writing and ~7MB for reading of 348MB test file... I'm sure though if I test it again with my PC it would meet the advertised 10MB writing speed.