Database Users

The Big Deal With SD Class....

So whats the big deal with the Class of SD cards...
I have read here and other places about not being able to use anything below Class 6.
If I understand correctly a Class 2 writes at 2mb/s, Class 3 writes at 3 mb/s, Class 4 writes at 4 mb/s..and so on up to Class 6....
So i understand that everyone is basically saying you need to be able to write at 6 mb/s....why is this and why cant I use my 4GB Class 2 Sdhc card to store caches and/or apps....I paid $7 for my 4GB card but didnt pay attention to the Class because i didnt think it would matter...
Thanks...

From what I understand you should be fine using it to move apps to the card. People say if you move data or cache you will experience a slowdown. Id say try it if you want, at worst you just undo the data/cache.

I tried using a brand new 4g class 2 card, and massive failure. I purchased an 8g class 6 on newegg.com for $17 shipped and the same install worked perfectly. My g1 now has 250+ apps and runs just fine with 40+mb free space on device (I left my data on there)

Apparently a good Class 4 card is good enough, but to be sure you really should go with a Class 6 one, or you might experience a lot of lag.

My class 2 all I did was run the apps off the card everything seemed to go good and then I wasn't able to update themes anymore any theme I tried to update said bad and would abort. And then my phone began to freeze all the time and apps began to force close or not ever launch. It work great for about a week and then all that started to happen. I picked up newegg the 8gb class6 about 2 weeks ago and have since to have a problem!

i have an 8gig class 4 and when i moved apps to the sd card my G1 became really sloooooooooooooow. apps took a while to open, and when i was finished with an app and hit the "back" arrow or the home button it would take 3-4 seconds for the home screen icons to show up. it was quite annoying.
i have gone back to running the apps from the internal memory and i'm back to top speed. i'll probably try again with a class 6 sometime soon.

well thanks...I will make sure to buy a Class 6 than...didnt think it was a big deal and couldnt find any others who did fine with other classes...

Smaller size sdcards work better then big sized sdcards (also known as high capacity)

OK so I've been running many version and builds of android since day one on my tmous hd2. At first it was with the stock 16gb sdcard, (till it got corrupted, LOL) so then I switch to a 2gb I had around. I have only formatted this 2gb card once in the begging and never again.many times I have deleted the android folder and many times I has switch to new builds ( I think I try everyones.latest I been using n very stable JDMS 1.3) n haven't had any issues. Like freezing or SOD. Now two days ago I help my friend with his and his wife's tmous hd2 with the 16gb card. So I did a fresh format fat32 then flash the same rom (ozDroid) and radio I been using for months. It results they are getting freezes and occasionally SOD. So for a test I took my wife's tmous hd2 with 16gb card did the hole setup an guess what the freezing and SOD is the more often..when I don't get any with my sdcard 2gb. Could there be an issue with high capacity cards. And could that be the reason why many tmous have the more problems with freezes and SOD
Sent from my HTC HD2 using XDA App

I use stock 16gb and dont have those issues.
Sent from my HTC HD2 using XDA App

this is common knowledge in the IT field. the larger the card, the more slowly it will write and access small files, such as the files needed to run android. take 100 small text files and copy them to a 256 thumb drive, and an 8 gb thumb drive. you can copy them all to the 256mb drive, and delete them all again, before the are all copied to the 8gb thumb drive. the 8 gb drive, will work much faster copying an .avi, or large file than the 256, but it sucks at lots of small files.
but it's good that you're posting your exp here. many people would not know this otherwise, and may stop experimenting with android due to frustration, when all they need is a $10 2gb card from walmart.
another couple tips when dealing with solidstate memory. just like a harddrive, files can become fragmented if you have multiple tasks or file transfers going at the same time. to avoid this, make sure each is done before starting another set of files. next, do not defrag solid state drives. they only have a limited amount of times they can read and write to each sector, and defragging, and excessive copying/deleting, wears down the material, and kills sectors of the drive. and last but not least, watch your battery. just as it says not to attempt an install with less than 50% battery, don't run your phone down to a dead battery when possible. because your booting of the microsd, it's constantly being accessed by read and write functions, and if the battery dies before it finishes writing, you get corrupted files, and you'll have to do your install all over.

No lockup or freeze with 16GB.

prking07 said:
I use stock 16gb and dont have those issues.
Sent from my HTC HD2 using XDA App
Click to expand...
Click to collapse
Same here. 16 gb SDHC, no problems.

I haven't noticed any difference between a Class 2 2gb, Class 2 16gb, or a Class 4 8gb - they all run about the same with not noticeable differences in boot time, smoothness, or SODs, even though the class 4 is 2x as fast.

hi guys,
before you post any comment, you can grab a none SDHC card, and do a comparison.
if you have benchmark software, please look at the "access time", the None-SDHC card always faster than the SDHC card. not the speed, but the access time.
after I change to 2GB SD Card, I never meeting any sleep, lag program with any version of roms.
if you don't have none-SDHC card, please do not make any conclusion.

16 gb class 10 kingston sdhc
works great
compaired a class 6 no name 8gb sdhc and the stock 16gb class 2 the class six lags less than the class 2 but the class 10 16 gb kingston is super fast

I am using class 4 8GB and 16GB, no diffrence found.

I can confirm, going from 16gb to 8gb, I've had far less issues with the 8gb card using the same setup. 0 SODs when I'd get them daily with the 16gb card. May or may not have anything or everything to do with it, but I'm sticking with the 8gb card. lol

My experience has been that performance has been about the same whether using a 2 GB SD card or a 16 GB SDHC. However, it seems that my 16 GB card was slower at one point because I had an excessive number of individual files on it. It's a double edge sword because you have all that capacity but the more you use it the slower it seems to run.

I had this issue aswell but I updated my radio to 2.12.xx.xx. and since then I have not seen any performance issue due to the SD card size.
Sent from my HTC HD2 using XDA App

qingcai said:
hi guys,
before you post any comment, you can grab a none SDHC card, and do a comparison.
if you have benchmark software, please look at the "access time", the None-SDHC card always faster than the SDHC card. not the speed, but the access time.
after I change to 2GB SD Card, I never meeting any sleep, lag program with any version of roms.
if you don't have none-SDHC card, please do not make any conclusion.
Click to expand...
Click to collapse
That's very presumptuous of you.
I fixed all of my lag and screen freeze problems with a combination of setCPU settings, ADW launcher settings, and updating my radio rom.
Before I finished doing all of that this morning, I'd get a freeze from wake fairly often. Since then, not a single freeze, and trust me, I've been trying to get it to freeze up.
Believe what you will my friend, but punishing yourself with a 2GB card just seems silly when people are outright telling you that the size isn't the problem.
Good luck either way!

apallohadas said:
That's very presumptuous of you.
I fixed all of my lag and screen freeze problems with a combination of setCPU settings, ADW launcher settings, and updating my radio rom.
Before I finished doing all of that this morning, I'd get a freeze from wake fairly often. Since then, not a single freeze, and trust me, I've been trying to get it to freeze up.
Believe what you will my friend, but punishing yourself with a 2GB card just seems silly when people are outright telling you that the size isn't the problem.
Good luck either way!
Click to expand...
Click to collapse
Yes ur are right with the new builds and using setting and programs like setcpu or even auto killers will help eliminate this problems. But I I said in the first post was that high capacity cards tend to give u more problems, using my 2gb (I think all the way to 6gb is non high capacity) I have no need for such adjustments to whatever build I use..u can read post 2, is very well explain there.
Sent from my HTC HD2 using XDA App

My 32GB did worked only one time, after first reboot i cant use android. But 2gb works like a charm

[Q] SD Card Worth It?

I am going to pick one of these up, but before I did, had a quick question (anyone with a WP7 can answer)
Do you feel that 8gb is enough space? Or do you wish you had more? Should I get an SD Card?

Most definitely. I have loaded most of my music and a few videos and I already used over 6GB. That's pretty much all the stock phone has. Now, I have over 14GB still left. Might put some movies on it.

My only disappointment in the focus is the 8GB stock NAND. For a $199 on contract device, 16GB really should be the minimum, especially considering a few other WP7 phones, to say nothing of Android phones and the iPhone, all start at $199 with 16GB.
That said, adding the SD card isn't that big a deal as long as you do it before you've filled the device up. For some reason there seems to be no ability to do a full backup of the phone by any means I've been able to find.

The problem with the SD Cards is that there's intense confusion/miscommunication about which cards work well. Just because it works with 6GB doesn't mean anything. What seems to happen is once you get to 8GB filled, the phone's performance takes a nose-dive, sometimes leading to losing all data.

"Enough space" depends on you, not us. I have an iPhone, iPad and iPod, all 16GB units, each with some 14GB or so of music & apps on them so it the first thing I did when I brought the Focus home was slap an 8GB card in there, format it and load it up. I have maybe 2GB free and it's worked without a single glitch for the past two weeks. For reference, mine is a Sandisk class 2. People seem to have problems with cards other than Sandisk and other than class 2 and I noticed absolutely no performance problems so if you're going to try it, try that and keep the receipt in case you need to return or swap it should something go sour.

Enough Space?
I agree with Mark, whether there is enough space or not really depends on what your usage requirements are.
I had a 32GB Zune and when I bought my Samsung Focus the Zune had over 20GB of data on it. So for me adding and 32GB SD card to the Focus was not only a desire but a very strong selling point for the Phone.
And yes, I am seeing a few issues with the Sandisk Card that is in it. Currently they are not enough to make me yank the Card because I (again) bought the device to specifically be a convergence device for myself and I am at heart a tester and tinkerer so figuring how exactly how WP7 works.doesn't work with an SD Card and the statement that MS and Samsung are working on a fix is enough for me right now.
Smaller Sized Cards seem to be more reliable than larger cards (not to mention less expensive) but that appears to anecdotal evidence as well. My 32GB Sandisk only causes freezes and resets when on Battery for example and I've not had anyone else confirm if they are seeing the same.
Not great answers but, hey, this is the fun of learning as we go along...
- MEK

FishFaceMcGee said:
The problem with the SD Cards is that there's intense confusion/miscommunication about which cards work well. Just because it works with 6GB doesn't mean anything. What seems to happen is once you get to 8GB filled, the phone's performance takes a nose-dive, sometimes leading to losing all data.
Click to expand...
Click to collapse
I have more than 11GB on my Focus with no issues at all. No slow-downs, no hiccups, no data loss period. I am currently using a PNY 16GB Class 2 card. I previously had a Centon 8GB Class 6 card with the same results.
If you read the thread on MicroSD cards, it seems there are some cards that have been working pretty much flawlessly. Both of the cards I mentioned have worked perfectly for me. I gave the 8GB to a friend and he is using it in his Focus as well.

For me, to really make a portable phone/audio/video device be best for me it would need at least 150GB of storage... and a few TB if i wanted to listen to music lossless and a few movies.

MKohlman said:
I agree with Mark, whether there is enough space or not really depends on what your usage requirements are.
I had a 32GB Zune and when I bought my Samsung Focus the Zune had over 20GB of data on it. So for me adding and 32GB SD card to the Focus was not only a desire but a very strong selling point for the Phone.
And yes, I am seeing a few issues with the Sandisk Card that is in it. Currently they are not enough to make me yank the Card because I (again) bought the device to specifically be a convergence device for myself and I am at heart a tester and tinkerer so figuring how exactly how WP7 works.doesn't work with an SD Card and the statement that MS and Samsung are working on a fix is enough for me right now.
Smaller Sized Cards seem to be more reliable than larger cards (not to mention less expensive) but that appears to anecdotal evidence as well. My 32GB Sandisk only causes freezes and resets when on Battery for example and I've not had anyone else confirm if they are seeing the same.
Not great answers but, hey, this is the fun of learning as we go along...
- MEK
Click to expand...
Click to collapse
You know, I was thinking about this the other day...the phone has 8GB of internal memory and if you put in an SD card it stripes data across it and the internal memory. If the card is 8GB or smaller that's fine but what happens if the SD card is larger than internal memory? It doesn't stripe the first 8GB and set the rest up as another partition and it does appear to use but it can't be striped. Now you've mentioned that smaller sized cards work better and my 8GB card works perfectly. I wonder if the file system's attempt to work with a larger card is inherently unstable? I know that if you put two different sized drives in a Windows box and stripe across them you will only end up with double the size of the smallest drive, not the actual sum of the two. Might be an interesting poll...indicate the size of your SD card and if the phone has been 100% stable since inserting it.

markgamber said:
You know, I was thinking about this the other day...the phone has 8GB of internal memory and if you put in an SD card it stripes data across it and the internal memory. If the card is 8GB or smaller that's fine but what happens if the SD card is larger than internal memory? It doesn't stripe the first 8GB and set the rest up as another partition and it does appear to use but it can't be striped. Now you've mentioned that smaller sized cards work better and my 8GB card works perfectly. I wonder if the file system's attempt to work with a larger card is inherently unstable? I know that if you put two different sized drives in a Windows box and stripe across them you will only end up with double the size of the smallest drive, not the actual sum of the two. Might be an interesting poll...indicate the size of your SD card and if the phone has been 100% stable since inserting it.
Click to expand...
Click to collapse
I'm not totally convinced based on comments in blogs that the disks are "striped". I think a lot of people are saying this and maybe using the term out of context and everyone just keeps using it. Has Microsoft actually come out to say "WP7 performs RAID 0 configuration"? For a phone OS which was never intended to see anything other than a single drive, don't you think throwing a RAID controller in there just for kicks is a little absurd?
The other term is "span" and if I had money, I'd bet that the two disks were spanned as a single partition, as opposed to striping like RAID 0 does.
Despite all of that, I have tried a 16gb class 4 with more issues than I cared for and currently have an 8gb class 4 with negligible issues. Any card you get, I'd run on Vista/Windows 7 and test for ReadyBoost. That at least tests the card for random access speed, which is important. My 16gb failed readyboost and had lots of issues in my Focus, whereas the 8gb passed and the only issues I've seen with that one are issues that other people might have experienced on their own phones sans sd card.

hyperzulu said:
I'm not totally convinced based on comments in blogs that the disks are "striped". I think a lot of people are saying this and maybe using the term out of context and everyone just keeps using it. Has Microsoft actually come out to say "WP7 performs RAID 0 configuration"? For a phone OS which was never intended to see anything other than a single drive, don't you think throwing a RAID controller in there just for kicks is a little absurd?
The other term is "span" and if I had money, I'd bet that the two disks were spanned as a single partition, as opposed to striping like RAID 0 does.
Despite all of that, I have tried a 16gb class 4 with more issues than I cared for and currently have an 8gb class 4 with negligible issues. Any card you get, I'd run on Vista/Windows 7 and test for ReadyBoost. That at least tests the card for random access speed, which is important. My 16gb failed readyboost and had lots of issues in my Focus, whereas the 8gb passed and the only issues I've seen with that one are issues that other people might have experienced on their own phones sans sd card.
Click to expand...
Click to collapse
I've read both, striped and spanned...who knows. Considering how slow SD memory always was in old WinMo devices, I didn't think it absurd to stripe data to provide the same kind of speed boost you get when striping hard drives. Hard as it might be to believe, it may have just been that WinMo was slow. I hadn't thought of the readyboost test, that's a good idea. Readyboost is pretty picky.

Kingston 8GB Class 4

As some people reported this sd card will cause multiple lags and slow down market place and app installing, others are saying its working fine for them.
Does someone know about a workaround?

Well I have a Kingstone 16GB card and I can confirm I am experiencing some lags while browsing & listening to music, i'm unsure of the installing speed issue since everyone on WP7 experience slow sync and slow deployment of XAP files, but it is terribly slow.
thinking on getting a new one just for WP7...

just test it without sd card for some time, its such a big difference
the question is if it can be fixed in some way or if its necessary to buy a completly new sd card

i've spent last two nights with installing wp7 on my kingston 8gb class 4 and my sandisk 2gb (hd2-bulk) over and over... my result: the 8gb kingston card is so much slower... not to speak about the annoying lags in marketplaas as described above and the multiple reboots on startup (up to 8 times till it boots all the way through to homescreen!) now i'm forced to stay on 2gb until a solution is found, or someone will sponsor a compatible 8gb card (or larger) to me

malsehn said:
i've spent last two nights with installing wp7 on my kingston 8gb class 4 and my sandisk 2gb (hd2-bulk) over and over... my result: the 8gb kingston card is so much slower... not to speak about the annoying lags in marketplaas as described above and the multiple reboots on startup (up to 8 times till it boots all the way through to homescreen!) now i'm forced to stay on 2gb until a solution is found, or someone will sponsor a compatible 8gb card (or larger) to me
Click to expand...
Click to collapse
At least the 2GB sandisk works for you, i got 2 of them and none are even recognized

Well I have 2 more cards
one is a generic 4GB i tested WP7 with which was great! but I didn't cofirm if the slowdowns occur after installing apps and adding music, I only synced about 10 songs before deciding to install WP7 on my kingston one, so I can't confirm that it was better, it just didn't lag, I can't know if the lag is an issue after loading things onto the SD card.
The one SD card I have is another Kingston 8 GB, same model like my 16GB, so it would be stupid to even try it since i've got everything configured for now on my 16GB.
I'm thinking about getting a Sandisk 16GB but i'm afraid i'll just throw money and this issues will appear again because they are size related...
The thing is, Does everyone experince slow downs when listenning to music? (which is the main thing I do with my phone) or that WP7 doesn't load apps sometimes? or when sometimes you swype left for the list and the icons of the applications that are insatlled on the SD card are still loading (grey image with a star).
Facebook is slow.
Because if this is the base performance for everyone i'll just stay with my Kingston.
It just seems that everything that's related to the SD card is working on and off.

The Kingston 4GB class 4 I have is very laggy, big difference with it out. I bought one of those SD cards that where approved as WP7 compatible by Sandisk.
My HD2 is in repair at the moment getting a new digitizer so I can't test it until it comes back.

tkato said:
Well I have 2 more cards
one is a generic 4GB i tested WP7 with which was great! but I didn't cofirm if the slowdowns occur after installing apps and adding music, I only synced about 10 songs before deciding to install WP7 on my kingston one, so I can't confirm that it was better, it just didn't lag, I can't know if the lag is an issue after loading things onto the SD card.
The one SD card I have is another Kingston 8 GB, same model like my 16GB, so it would be stupid to even try it since i've got everything configured for now on my 16GB.
I'm thinking about getting a Sandisk 16GB but i'm afraid i'll just throw money and this issues will appear again because they are size related...
The thing is, Does everyone experince slow downs when listenning to music? (which is the main thing I do with my phone) or that WP7 doesn't load apps sometimes? or when sometimes you swype left for the list and the icons of the applications that are insatlled on the SD card are still loading (grey image with a star).
Facebook is slow.
Because if this is the base performance for everyone i'll just stay with my Kingston.
It just seems that everything that's related to the SD card is working on and off.
Click to expand...
Click to collapse
im experiencing the same, but as i said its probably related to the kingston sd card, its not the base performance
everything works awesomely fast without the sd card inserted...

Deploying applications takes ages, music in Zune stutters, games lag... It's clearly the bad performance of our Kingston...

I have 4 MicroSD :
sandisk 2gig class4
Sandisk 2gig class2
Kingston 4gig class2
Kingston 4gig class6
Sandisk 2gig class2 is the best.Class4 drain more battery and is more lag.

I have 2 MicroSD
kingston 16Go Class 2
kingston 8Go Class 4
16 c2 is perfect
8 c4 is lag and slowdown

Inersting but it seems all the laggy SD's are class 4, while class 2 works good, mine is a class 4 as well.

I have 2 MicroSD
Samsung 8GB Class 2 ( lag and slowdown )
Nokia 4GB Class 6 ( really fast and good battery )

I have a 16Gb Kingston class 4 and magldr doesn't even recognize it let alone wm7 I think its down to that, like the battery issues most are having, in time these will be fixed

I confirm, don't use Kingston class4 (I'll try to get a refund from amazon :/)
No problem with my sandisk class2

same here, 8GB class 4 Kingston doesn't even boot anything :-(

Yea I have a Kingston class 4 16gb that magldr doesn't even read, I have just put a post in the HD2 general about it asking about it
Sent from my duel booting beast of a phone

[q] why it takes long time to install apps

Any idea why it takes so long to install apps in wp7

I don´t have any complaints so far... it´s fast here.
Many slowdowns, however, seem to be caused by using sub-optimal, if not incompatible, SD cards.

Change the SD card!!!! I migrated from a Kingston Class 4 4GB (lag in WP7 + slow app install) to a 16 GB Adata Class 10 card and now everything is really flying high SanDisk cards should be your best bet as of compatibility. I switched to Adata because I got it as a present.

thanks for the reply guys
i am using sandisk 16 gb class 6, so you think i should change card or the is some other problem

It´s hard to tell from distance... if you´ve got another card, it might well be worth a try. Sandisk usually work, but then again, some don´t. I think that was also a major issue for HTC when they had to notice lags and malfunctions of some of their WP7 devices which use SD cards instead of soldered memory...