Differences between SD & SD-S cards - MDA III, XDA III, PDA2k, 9090 General

Hello,
I find 2 references in memory cards, is there a true difference in the use or the security between them.
Are all SD cards compatible ?
There may be a thread on this topic, any link welcome,
Thanks
Jean-Jacques

I beleive, could be wrong. That one is high speed and the other is standard. They are both compatible with each other. But the device reading the card must be high speed also. Otherwise it will read it at the slow bit rate.

Related

Using fast SD cards?

I see these 66x superfast SD memory cards advertised. Will using one speed up my blue angel?
Can programs use this SD card for operating memory or can they only use the intenal memory?
Does having <5mb avaialable slow down your device?
Fast Sd Cards
Fast Sd cards are only useful for SLR Pro cameras. The rest of the devices are using normal card reader slots. i.e. even if you were to use a fast SD card in the sd card slot,you will only get the normal speed.
by rest of the devices, i mean, all pocket pcs, ppc phones, phones and such devices...... :x
moali77 is correct. it won't make much of a difference in your pda. however, if you use a card reader, or happen to have a digicam that can utilize the speed, you will be better off.
example: i played atlantis redux recently 100mb+ required to be put on your sd card. instead of copying it through activesync, i put it in my usb2.0 card reader, copied it over, in far less time than it would've taken if i did it the other way.
but if you don't plan for much of that, then don't bother paying the premium for a fast card =)
Well I bought a Kingston Elite Pro Secure Digital 1GB, think It's 7.7/8.2MB Write/read
It made my TomTom go way faster planning routes and generally give me better performance from other apps.
I dont know the Top speed for the BA SD Slot, but you should look at the speeds of the card you are planning to buy
bosjo said:
Well I bought a Kingston Elite Pro Secure Digital 1GB, think It's 7.7/8.2MB Write/read
It made my TomTom go way faster planning routes and generally give me better performance from other apps.
Click to expand...
Click to collapse
Have others experienced similar variations with different SDs?
I recently responded to Wamatt's other posting about SD cards in the BA accessories forum. In it, I've described my experiences with the SD card listed in my sig and BA speed tests I've done with it.
See http://forum.xda-developers.com/viewtopic.php?t=26903 for additional information.

What is the data transfer speed for the P3600i using MiniSD or MiniSDHC cards?

I am curious to know if there is any real benefit to using the SDHC cards which represent larger capacities and faster data transfer speeds.
As i am likely to simply use a 2Gb card, i have the choice of SD or SDHC. But if i know what the actual speed capacity that they handset can handle then that would be very useful.
Presently my 1gb MiniSD card and store TomTom6 on it along with the maps and POI's but i have found that if i load too many POI options then TT6 hangs. So i think this has something to do with the transfer rates. (i could be wrong, but thats my suspicion)
All comments appreciated.
As its unlikely that anyone would have both a regular SD and SDHC cards, could you please just list the read and write transfer rates with the card you have. (please indicate which brand and model of the card)
Thanks
GLO said:
I am curious to know if there is any real benefit to using the SDHC cards which represent larger capacities and faster data transfer speeds.
Click to expand...
Click to collapse
Hello GLO,
the benefit of SDHC is capacity and a standardized write-speed-rating for the cards. The speed is not necessarily higher, as there were a lot of fast SD-cards in all flavours before.
Coming from SD and CF for my DSLR, there has been a phenomenon: While the better SD-cards were really fast, most manufacturers have not built their newer SDHC-cards as fast as their best SD-cards, but just maintained the minimum level for the various speed-ratings defined by the SD-association.
The data for my 2GB Sandisk Standard (no Ultra or Extreme) card according to SK-Tools:
FAT16, 32KB-Cluster:
average write speed: 410,34KB/s
average read speed: 613,48KB/s
From what I have seen on my trusty Dell, the devices do not show much of a difference between standard and fast cards, thus I have just gone for a standard card in my Trinity.
TG.
Hi TG,
Thanks for that. Some very good points you raised!
What card are you using?

2GB MicroSD and 8GB MicroSDHC Card Benchmark

I´ve done a Benchmark with the MicroSD Cards I had available.
Please find the results attached.
Bought the 8GB SDHC Card at the same place as Snake28:
http://forum.xda-developers.com/showthread.php?t=349888
I am not able to view the benchmark
I made all required steps, I registered, waited for activation.
Still not able to view your benchmark.
I have to buy a microSD card. I am looking for 2 GB.
I use to look arround and buy best performance components, but now I was not able to find my way.
I would be grateful if you would supply me the results.
[email protected]
Hi mboxmbox,
I just send an e-mail to the adress you provided with the Benchmarkresults attached as a pdf File.
Sorry that the provided zip File above was not accessible for you.
Regards
Jabami
I got the requested file
I would like to thank you for your very quick response, for your help.
It is strange that manufacturers do not provide enough info regarding this type of card, while for other cards there are available full specifications : CF cards are much better documented, as you know. I think that the number of devices using smaller size cards will grow, this is a natural tendency.
I just recently bought a device that is able to use microSD card and I use to carefully look around and read others experience ; vendors tend to say only part of the truth. I want to use the card not only “inside” of the device, but also to carry data and feed it to several PCs, so speed of the card might be important.
m.
Im glad that I could help you.
But - as you see I did not measure the MicroSd Cards performance when connected to a USB 2.0 Port at the PC. As far as I know, the Artemis Device is just capable of USB 1.0 to read/write to the internal MicroSD Card. So it can be expected that performance will rise significantly when connected to a USB 2.0 capable PC.
Regards
Jabami
Great results.. Could you hook me up with SKTools? I'm receiving my 8Gb card tomorrow or Saturday and I would like to benchmark it and post the results for you to compare.
You will find the Software here:
http://www.s-k-tools.com/
Its not free, but you can use it for a period of time. Which should be enough to do some Benchmarking.
Best Regards
Jabami
USB 1.1 is 12 MBit/s
Does your benchmark is MByte/s ?
2 gb micro sd card
dear all,
im using HTC touch, right now im using 1 GB micro Sd card, i want upgrade it to 2GB. my htc touch will compatible for 2GB card? it will work smoothly or it will hang?
pls suggest me.........

Some questions about micro SD

Hi guys, I have a few questions about micro SD:
1) Does higher class drain more battery?
2) I just purchased a LG optimus 2x, is a class 6 enough for me? or do I need to go all the way to class 10?
3) Will higher class cause lagness to the phone?
Thanks guys
akira de aimbuster said:
Hi guys, I have a few questions about micro SD:
1) Does higher class drain more battery?
2) I just purchased a LG optimus 2x, is a class 6 enough for me? or do I need to go all the way to class 10?
3) Will higher class cause lagness to the phone?
Thanks guys
Click to expand...
Click to collapse
1. From what I've seen, it seems some higher class cards drain battery more... I think the brand and quality of chips make more difference with battery, though.
2. Is class 6 enough for what? What are you using the card for? If it's strictly for taking pictures or videos, or transferring large files, or other tasks that you only need sequential write and reading, then higher class would be quicker for that. But class 6 is pretty quick with sequential reading/writing... it's up to you if you need higher. What are you using the card for?
3. Yes, higher class cards can cause lagness if you have apps or OS files on it, or if the phone is trying to access many different parts of the card quickly. Generally, for using with a phone, you will get better performance with class 2 or 4 cards. Higher class cards generally have slower access times and slower random access speed and random read and write speeds. Class 6 and 10 are better for digital cameras, or for transferring large files, but for use with a phone, where you may run apps off it or have the OS trying to access many bits of data from different parts of card, class 2 or 4 usually perform better there.
zarathustrax said:
...Yes, higher class cards can cause lagness if you have apps or OS files on it, or if the phone is trying to access many different parts of the card quickly. Generally, for using with a phone, you will get better performance with class 2 or 4 cards. Higher class cards generally have slower access times and slower random access speed and random read and write speeds. Class 6 and 10 are better for digital cameras, or for transferring large files, but for use with a phone, where you may run apps off it or have the OS trying to access many bits of data from different parts of card, class 2 or 4 usually perform better there.
Click to expand...
Click to collapse
Can it be true; I suspect the "slower access times and slower random access speed and random read and write speeds" coming from higher class (10) microsd cards have to do also with bad quality, cheap (see chinese) chips that hit the market with the class 10 hoax. I hope "serious" manufacturers will produce cards that could achieve not only sequential, but also satisfactory random speeds.
Are there any sites that rank microSD cards based on random access time?
THG has some data for miniSD cards but most other sites have scattered reviews and no direct ranking.
me00016 said:
Can it be true; I suspect the "slower access times and slower random access speed and random read and write speeds" coming from higher class (10) microsd cards have to do also with bad quality, cheap (see chinese) chips that hit the market with the class 10 hoax. I hope "serious" manufacturers will produce cards that could achieve not only sequential, but also satisfactory random speeds.
Click to expand...
Click to collapse
Well there are quality cards that do good at both... a Sandisk class 4 is one of the best all around I've seen. It pretty much gets class 6 sequential write speeds, and still has great access time and random speeds.
But the lag cause by class 10's and 6 isn't only because of low quality... it's caused because the higher class chips are designed to initialize the part of the card it's about to use, which gives much better sequential speeds, but hurts the access time and random read and write where many parts of the chip are accessed quickly getting small bits of info in many different parts. In this case, the initialization that the chip is doing causes it to take much longer, as it still initializes each part before accessing it. That extra step it's doing adds up to a lot of extra time when its using lots of random parts of the chip to read or write only a small bit of data.
Cards that don't do this initialization and just begin accessing immediately is obviously going to be quicker when using many different parts of card.
zarathustrax said:
2. Is class 6 enough for what? What are you using the card for? If it's strictly for taking pictures or videos, or transferring large files, or other tasks that you only need sequential write and reading, then higher class would be quicker for that. But class 6 is pretty quick with sequential reading/writing... it's up to you if you need higher. What are you using the card for?
Click to expand...
Click to collapse
Most probably I will dump everything into the card, reading games from it, using gps with map files inside the sd...etc. So I guess a class 6 is sufficient. But now people are telling me even class 4 is sufficient, while some say that they observed huge different from class4 vs class 6, I got confused
May I know if android is using sequential access or random access? Or is it depends on the software?
akira de aimbuster said:
Most probably I will dump everything into the card, reading games from it, using gps with map files inside the sd...etc. So I guess a class 6 is sufficient. But now people are telling me even class 4 is sufficient, while some say that they observed huge different from class4 vs class 6, I got confused
May I know if android is using sequential access or random access? Or is it depends on the software?
Click to expand...
Click to collapse
I'm confused too, after 2 months trying to find the optimum 32gb microsd for my SGS. Well, the thing gets complicated (especially for 32gb capacities) because of many reasons:
- Inconsistent quality assurance-high percentage of defect cards, sometimes of the same lot, even from top brands. This could be not only a non working card, but also small but critical problems like write failure, freeze, etc.
- Users, we don't know what we want microsd for; surely we all want to upgrade the memory of our phones, but it seems that others don't like to wait long transfering 1080p movies in the device, others want to use app2sd with android. I've come to the conclusion that right now in the market there is not a product that can do all jobs satisfactory (maybe Sandisk c4?).
- Fake cards.

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.
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

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