MicroSDHC class 2,4,6,8 for San Francisco

[Guest Francesco89]

Hi, I wonder to what class of speed comes the orange san francisco? I think the class of a microsd is very important for a smartphone because it speeds up the reading (gallery) and writing.

[Guest thomas01155]

It comes with a class 2 card.

Edited October 28, 2010 by thomas01155

[Guest Francesco89]

that leaves the phone I do not think they put you on top of the microsd ..... if read as a class for 6 or 8 would be another thing ..... the applications installed on the sd would be faster, the gallery, themes, music .... everything would be better .... this already happened to me with other phones ... and let me know if anyone has tried to put the microsd class higher than the 2 to see if performance improves

[Guest Azurren]

that leaves the phone I do not think they put you on top of the microsd ..... if read as a class for 6 or 8 would be another thing ..... the applications installed on the sd would be faster, the gallery, themes, music .... everything would be better .... this already happened to me with other phones ... and let me know if anyone has tried to put the microsd class higher than the 2 to see if performance improves

Actually the speed difference is only really noticeable when transferring files or using SWAP (Which the San Fran has no need for)

I suppose it would help large apps stored on the SD card (A2SD / Froyo) such as Angry birds / Skype load 1-2 seconds faster.

But most people wouldn't notice the speed increase

I have a class 4-6 (Depends what mood it's in)

[Guest blauwal26]

The whole class definition is basically useless since it's just a matter of quality control, most class 2 cards perform as well as class 4, it's just that it isn't guaranteed and hasn't really been checked. The best you can do is test the read/write speeds using dd.

[Guest Francesco89]

Anyways since I have to buy a microSD for my San Francisco, honestly I think I'll buy a Sandisk Mobile Ultra 8GB Class 6 at the time .... but at least I'm sure is very variable quality

[Guest asim18]

I'm using a Kingston 4GB Class 4 SDHC card. I get a sustained write speed of 11MB/s, and a read speed of 21MB/s. Both read and write speeds exceed Class 4 specification by miles.

This is using a straight USB connection with the phone, no special card reader.

So don't take SDHC classes so literally, you should base your purchase on actual benchmarks, reliability and reputability.

I would also like to mention that the included SD card is absolutely crap. Dispose of it immediately. I was getting about 900KB/s write speed, which is disgraceful.

Edited October 29, 2010 by asim18

[Guest asim18]

It comes with a class 2 card.

This is incorrect.

The included card is Class 0.

I can prove this because the actual card itself bears no Class rating, and the write speed I achieved was under 1MB/s.

[Guest zurpher]

This is incorrect.

The included card is Class 0.

I can prove this because the actual card itself bears no Class rating, and the write speed I achieved was under 1MB/s.

Do you guys have a recommendation what speed class a microSD card for the SF should have? I've read somewhere that one should aim for class 4 but would like to hear your opinion.

[Guest Mike_P]

This is incorrect.

The included card is Class 0.

I can prove this because the actual card itself bears no Class rating, and the write speed I achieved was under 1MB/s.

Seems the supplied cards are quite variable, I've just pushed a couple of vids across, one @4.4MB/s and the other 3.9MB/s.

[Guest Alex_P]

I have a 16 GB Kingston card in mine that is rated at class 4, but actually gets class 6 - 8 speeds on write, and loads more on read. Everything seems fine with that, but I haven't moved any apps to it.

[Guest agpoli]

The whole class definition is basically useless since it's just a matter of quality control, most class 2 cards perform as well as class 4, it's just that it isn't guaranteed and hasn't really been checked. The best you can do is test the read/write speeds using dd.

I know, I'm replying to a post made several weeks ago, but I think it's important to clarify this. So:

It has nothing to do with quality controll. A Class 2 card will never perform as well like a Class 4 card, well maybe it will, when they are both brand new. From Wikipedia:

"The Speed Class Rating is the official unit of speed measurement for SD Cards, defined by the SD Association. The Class number represents a multiple of 8 Mb/s (1 MB/s), and meets the least sustained write speeds for a card in a fragmented state."

As you can see both card will be loosing performance, but at the end, the Class 4 card will be outperforming the Class 2 one by two times. Every card gets fragmented during the everyday use.

[Guest Raspa]

The class rating is only for the write speed anyway - read speed is pretty constant across the classes. Class 2 or Class 8 won't make a difference to playing music, viewing images etc.

[Guest nicksoph]

There are some apps out there that will test your speed. Sorry can't think of the names off the top of my head but wanted to add that the sector size seems to make a difference to speed.

It might be an over simplification but it is generally best to stay with the sector size that the card originally came with.

[Guest zurpher]

There are some apps out there that will test your speed. Sorry can't think of the names off the top of my head but wanted to add that the sector size seems to make a difference to speed.

I would appreciate if you (or someone else) could recommend tools to test the speed between the SF and the SD card. Thanks.

[Guest zurpher]

I would appreciate if you (or someone else) could recommend tools to test the speed between the SF and the SD card. Thanks.

I have now found one tool called J Disk Benchmark. Similar tools have been discontinued.

This is incorrect.

The included card is Class 0.

I can prove this because the actual card itself bears no Class rating, and the write speed I achieved was under 1MB/s.

I have similar results but what I find most surprising is that the write performance for the internal memory is less than 1MB/s. If that is correct, it might indicate that one doesn't need fast memory (or SD card) for a reasonable performance. I would appreciate your thoughts on this.

[Guest deusum86]

I was wondering a long time which class I should use in my mobile phone... fortunately a college has access to a lot of this cards so i tried different classes starting from class 2 with ending at class 8

However the result was almost the same (on win7 pc cardreader, on win7 pc SF-USB connection and on the sf itself) it seemed to me the lower class the card was, the faster it could write small files (under 100kb) if the files are bigger (over 10mb) the higher classes win. I can't explain the results.. but I tested it twice.. the cards were all from kingston...

If you're going to write your thumbnails folder or something like this to the sd.. you probably want a class 2... but if you want to put the latest episode of your favourite series on... get a high class one..:(

I bought a class 4 because it seems to me the best compromise..;)

[Guest Phoenix Silver]

i'm wondering if it exists a dual sd card adaptator like a dual sim adaptator ?

[Guest rbbrslmn]

i'm wondering if it exists a dual sd card adaptator like a dual sim adaptator ?

never heard of one, the two cards would be sharing the bus if you could get one which would massacre speeds