Is a Class2 SD card sufficient for running Android? - HD2 Android Q&A, Help & Troubleshooting and Genera

Hi all,
I'm going to finally have some spare time this weekend and might even get to have a mess around with Android on my HD2 if I get lucky! My concern is that I have a 16GB Class2 microSD in my Leo and while looking at HD2 stuff on ebay came across this.
The seller states that Android won't run (properly?) on his 16gb Class2 and includes a Class6 8gb card aswell for this purpose.
What's everyone's experience with running Android on a slower card? From looking around I've seen people saying 'there isn't much difference' for most things but a lot of contridictions for others.
Thanks gang!

I have no issues with my Android build currently, and it's on a 4gb Class 2 SD card.
It does help having a faster one, but It's not the end of the world.
Phil

Have been testing out froyostone sense build on a 2gb class 2 card and it's like lightening So yes, would format first though otherwise you will get lag.

Cheers - yep I won't forget to format, been reading the threads while working this week... taken in loads of info, just need to find the time to actually get it rolling

I was wondering the same thing. I installed froyostone 08.07.2010 using miri Rom on stock radio on a friends hd2 and it freezes and comes back to life very often. Would a higher class sdcard solve his problem?

I think they guy on eBay is talking rubbish. I run darkstone's 2.2 perfectly well on a 16GB Class 2. A Class 4 would probably help a little bit, but I'm not that fussed really.
I'd be more concerned about getting dodgy copies of Transformers from them!!

murdaralph said:
I was wondering the same thing. I installed froyostone 08.07.2010 using miri Rom on stock radio on a friends hd2 and it freezes and comes back to life very often. Would a higher class sdcard solve his problem?
Click to expand...
Click to collapse
The whole OS and all animations etc, or just touch screen response?
If its the touch screen, that's a known issue and will be addressed in due course.
Phil

It's in german, but i guess u may figure it out.
h**p://***.chip.de/bestenlisten/Bestenliste-microSD-Karten--index/detail/id/867/

I have a kingston class 2 , not working.

qingcai said:
I have a kingston class 2 , not working.
Click to expand...
Click to collapse
A Little more information would be useful, what's not working about it? How's it formatted? Has it even been formatted and then had a new build copied to it?
Phil

i never had issues with a class 2 before... no SOD or anything... although after switching to class 4, there is noticeable speed. now in class 10, a lot faster. but no real issues in class 2 except a tad slower (but decent speed nonetheless)

I use the 16gb class 2 card and its quick with decent quadrant tests. I think its because android loads into ram (please correct me if I am wrong, ill search for this later). I think there are apps that read or write to folders on the SD card that would gain from speed of a class 6 or 10 card and if I am right about loading to ram the boot up time could receive a benefit.
Personally I am looking to get one just to access media faster and for taking pics and vids as there is a write delay that's typical with all phones. If it helps android in its current state the cool but I'm not in a rush. Development here have made great strides in making android snappy and android is an awesome is as it is for handling background tasks. Much to the credit of Linux but I find android to be a faster evolution then most mobile oses. Much to the credit of being open source and encourage community development. Nothing here is illegal but maybe some grey areas in closed source distributing which cyanogen had an interesting situation that was resolved quickly with Google's assistance.
But I am off topic now. Yes it would help with some things but don't break the piggy bank over it.
Hope my thoughts are helpful. It would be better to get feedback from those that have done it and get before and after boot, quad, and market download responsiveness tests. I may have a class 6 8gb card somewhere I can test later tonight. I would do fresh sdformatter formats with nothing but android on the card to get a somewhat standard benchmark.
Sent from my HTC HD2 using XDA App

Mine is 16gb class 2, with the latest fullram zimage, i score 29.2fps in neocore test
and can play sparta! very smooth, also the asphalt 5

kerman19 said:
The whole OS and all animations etc, or just touch screen response?
If its the touch screen, that's a known issue and will be addressed in due course.
Phil
Click to expand...
Click to collapse
the touch screen. The SD card was quick formatted. Would that make a difference in the builds performance ?

I'm using a Kingston class 2, but it performs with 5,5MBs writing speed when used in a computer slot, so in practice its a class 5,5. Works great! Froyostone sense v1

pappadj said:
I use the 16gb class 2 card and its quick with decent quadrant tests. I think its because android loads into ram (please correct me if I am wrong, ill search for this later). I think there are apps that read or write to folders on the SD card that would gain from speed of a class 6 or 10 card and if I am right about loading to ram the boot up time could receive a benefit.
Personally I am looking to get one just to access media faster and for taking pics and vids as there is a write delay that's typical with all phones. If it helps android in its current state the cool but I'm not in a rush. Development here have made great strides in making android snappy and android is an awesome is as it is for handling background tasks. Much to the credit of Linux but I find android to be a faster evolution then most mobile oses. Much to the credit of being open source and encourage community development. Nothing here is illegal but maybe some grey areas in closed source distributing which cyanogen had an interesting situation that was resolved quickly with Google's assistance.
But I am off topic now. Yes it would help with some things but don't break the piggy bank over it.
Hope my thoughts are helpful. It would be better to get feedback from those that have done it and get before and after boot, quad, and market download responsiveness tests. I may have a class 6 8gb card somewhere I can test later tonight. I would do fresh sdformatter formats with nothing but android on the card to get a somewhat standard benchmark.
Sent from my HTC HD2 using XDA App
Click to expand...
Click to collapse
You have experience with your G1, the class 6 I use on mine makes definite difference when running apps from your sd card. I've been alternating using my 16 GB Class 2 and my 8 GB Class 6 in my HD2 but I haven't seen any speed difference with android so I believe that it runs on the internal ram.

i think class 2 is enough

murdaralph said:
the touch screen. The SD card was quick formatted. Would that make a difference in the builds performance ?
Click to expand...
Click to collapse
Touch Screen lag/freezing is a known issue right now and doesn't relate to the SD card.
It's being worked on.
Phil

I have a class 2 16GB sandisk drive and score 1578 in quadrant standard, that said i usually get write speeds of around 6MB/sec on my computer

i personally think it helps a bit ( i ws previously running Android off the 16GB class 2 card the HD2 came with) but experienced some lag when scrolling.
That said, it was an early build of Android so it was probably just that.
The thing is, 8GB class6 cards are relatively cheap to buy (i picked up an A-DATA 8GB class 6 for $21 canadian at CanadaComputers)
so..why not upgrade to the class6 card? I'm sure it wouldn't hurt and no matter what you'll experience at least have SOME sort of performance gain in other aspects (music, pictures, file managers, etc)

Related

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] microSD card problem

Hello,
I installed Android on my HD2, worked perfectly for 2 weeks. But my microSD was only 2GB, so I buyed a new one.
Kingston class 4 8gb microSD. Putted everything just on the new SD card, didn't changed anything! Formatted it also to FAT32.
Now the problem is that Android is VERY slow with getting out of standby, takes sometimes 10 seconds. I get a black screen for 10 seconds and then Android comes up.
Also starting up Android takes ages and it sometimes just freezes or gives a blue screen.
Has this something to do with Android or is the microSD card broken in a way? I can still move/delete files on the microSD card.
Anyone got at solution?
Thanks
Did you try a different build? Perhaps try Mdeejay rEVOlution build, fastest build i've used so far,very very fast, smooth and stable. Also try updating your radio.
I bet there are several utilities to test the read and write speeds on your microSD card. You'll need a cardreader in your pc to do that, trying it through WM6 won't work because the USB will be the one controlling the max speeds.
I hope this helps a lot of people struggling with the speed of android running off SD.
My suggestion is that the card size, and not just the card speed plays an important part in the speed at which android runs...
My Evidence. I first installed various builds on a variety of Sandisk 2GB and 4GB Class 2 cards. They all ran super fast... I mean no lag at all, ever. It might as well have been a Desire HD. Being that i wanted more space I used my 16GB Sandisk Class 2 that I have been using for WM, reformatted it and installed android. It was cripplingly slow. Unusable in fact. (i tried reformat/reinstall a couple of times before giving up). I then invested in a Class 4 16GB and installed the same build. Not surprisingly this was faster, usable but still not as fast as it was on the 4GB Class 2. I am going to go back the the 4GB card unfortunately until NAND arrives.
Murg
murgers said:
I hope this helps a lot of people struggling with the speed of android running off SD.
My suggestion is that the card size, and not just the card speed plays an important part in the speed at which android runs...
My Evidence. I first installed various builds on a variety of Sandisk 2GB and 4GB Class 2 cards. They all ran super fast... I mean no lag at all, ever. It might as well have been a Desire HD. Being that i wanted more space I used my 16GB Sandisk Class 2 that I have been using for WM, reformatted it and installed android. It was cripplingly slow. Unusable in fact. (i tried reformat/reinstall a couple of times before giving up). I then invested in a Class 4 16GB and installed the same build. Not surprisingly this was faster, usable but still not as fast as it was on the 4GB Class 2. I am going to go back the the 4GB card unfortunately until NAND arrives.
Murg
Click to expand...
Click to collapse
Thanks for the reply!
First i'm going to test the Mdeejay rEVOlution build, hopefully it will run smooth and fast. If not, i'm gonna send back my 8GB card and get a new 4GB class 4 card.
At the moment I'm running Froyostone 3.2, works now perfectly with the 2GB microSDcard.
I will post the results.
murgers said:
My suggestion is that the card size, and not just the card speed plays an important part in the speed at which android runs...
Click to expand...
Click to collapse
I totally agree with this, although I cannot figure out why.
I tested with two almost identical cards, both Samsung class 4, one 2Gb, one 8Gb, formatted FAT32 64k clusters via the same memory card reader/pc. The 2Gb one whizzed along with the build I'm running now, the 8Gb one occassionally stuttered and stalled. Seems odd to me, unless fragmentation comes into play maybe?
The only reason I have stuck with the 8Gb is for my music. Oh how I'd love to stick with my 2Gb card for the speed and have a second SD slot for my music.

SD read/write speed causing lag on my HD2 but...

So I downloaded this app call H2testw.exe to test for legit sdcards but it also tells the read/write speed as well. I am testing my 8gb and 1gb cards. I set it to write a 300 mb files to the card and verify it.
Info about Android running on the two cards:
8gb = lags coming out of sleep, touch screen freezes, write~7.5 mb/s, read~12mb/s
1gb = no lags, no touch screen, write~4.3mb, read~13mb/s
I'm confused. The read speed is almost the same yet the 1gb microsd is more responsive running MDJ android compared to the 8gb microsd. Any thought?
UPDATE: Maybe this is what's causing the problem. Stolen from Engadget.
What we've learned from our tipsters and from documents culled from Microsoft, Samsung, and others is that the big issue is random access performance -- a figure that isn't taken into account in a card's class rating. Ironically, Microsoft discovered in its testing that cards with higher class ratings actually performed worse on Windows Phone 7 because the tweaks card manufacturers make to achieve high sequential throughput can actually hurt random access times. There's some rocket science involved here, but basically, it's a tradeoff and a bit of a gamble -- if a manufacturer tunes a card for a high class rating, it takes more time to access the first byte at a new location on the card because it's optimizing access for that area of memory, but once it does that, it can blast sequential bytes at very high speed. If you've got a lot of small reads or writes you need to make to different files at different locations in the card's memory, though, you really start to suffer. Cards with lower class ratings tend to spend less time optimizing sequential access prior to the first read / write operation, so it can move around the card (that is, access it randomly) much faster.
Click to expand...
Click to collapse
Source:
http://www.engadget.com/2010/11/17/windows-phone-7s-microsd-mess-the-full-story-and-how-nokia-ca/
They are probably different classes, plus it naturally takes longer with a bigger card because there's more files and more space to read and write
Sent from my HD2 Nexus One using XDA App
I get screen freezes with 8gb and up but rarely with new builds, haven't tried a card higher than class 6
Also I'm on radio 2.15
Sent from my HD2 Nexus One using XDA App
Oddly enough, I have two 8gb cards, one class 4 the other class 6, and they hiccup more than my 16gb class 2.
Now that is weird.
I'm lost myself...I'm thinking off just getting me a 4gb card and hope for the best...
I heard the 16gb class 10 is perfect but it still cost to much for nand to be around the corner
Sent from my HD2 Nexus One using XDA App
16 gb class 10 no lag cost me over 100 pounds tho
Sent from my HTC Desire using XDA App
Cheapest 16GB - lags from time to time :/
Maybe defragmentation may help?
tomus said:
Cheapest 16GB - lags from time to time :/
Maybe defragmentation may help?
Click to expand...
Click to collapse
Defrag wont help...scan for errors...try to have only the android folder and see if it makes a different ..
Btw, guys...
all sd cards are not created equal. all sd cards of the same CLASS are not created equal.
Check out the ongoing drama with win7 phones with SD slots....
class measures throughput, what affects the SOD and related issues is random access speed, not throughput so much.
It's just my 2 cents, but I've tested Class 2, 4, and 6 MicroSDHC cards and found very little noticeable difference once Android is fully booted up and running on the HD2. Moreover, none of the cards create screen freezes or SOD issues or high battery drain problems here. That said, I have noticed that the actual boot time and file transfer speed (from the PC to the card) can be faster on average with quality higher class rated cards of the same size. Also, I've found that the larger the card size, the longer the android boot time, no matter the class. Guess that makes sense, as the system need to read more sectors with larger size cards. Please note that I've only tested Sandisk, Toshiba, TopRam and Samsung cards to date. What's kind of strange is that the Class 2 16 & 32GB Sandisk cards run just as well or slightly better for some reason than some of my higher class rated cards. Go figure...
As far as issues go, I recommend only using quality brand name cards, no ebay fakes or cheap no name brands. Also, I've had great luck formatting all my cards with SD Formatter v2.0 and v3.0, using the quick format mode with the standard 32kb cluster size.
Best to all,
R
rhacy said:
It's just my 2 cents, but I've tested Class 2, 4, and 6 MicroSDHC cards and found very little noticeable difference once Android is fully booted up and running on the HD2. Moreover, none of the cards create screen freezes or SOD issues or high battery drain problems here. That said, I have noticed that the actual boot time and file transfer speed (from the PC to the card) can be faster on average with quality higher class rated cards of the same size. Also, I've found that the larger the card size, the longer the android boot time, no matter the class. Guess that makes sense, as the system need to read more sectors with larger size cards. Please note that I've only tested Sandisk, Toshiba, TopRam and Samsung cards to date. What's kind of strange is that the Class 2 16 & 32GB Sandisk cards run just as well or slightly better for some reason than some of my higher class rated cards. Go figure...
As far as issues go, I recommend only using quality brand name cards, no ebay fakes or cheap no name brands. Also, I've had great luck formatting all my cards with SD Formatter v2.0 and v3.0, using the quick format mode with the standard 32kb cluster size.
Best to all,
R
Click to expand...
Click to collapse
Great info here. I think I will just order me a new card from a reputable brand. Maybe my card is just getting old. Maybe a 16gb from Amazon will do. They aren't too expensive nowaday. ~$26.
Does the Radio version effects the lag of the sd card? Or the kernel?
distruct said:
Does the Radio version effects the lag of the sd card? Or the kernel?
Click to expand...
Click to collapse
No, not on the sd but radio does effect how the build will run, your phone calls, your battery.
Could this be the reason why class don't matter on hd2 android? I mean even some class 4 & 6 have lag and sod problem. I pulled this bit from engadget. It's an article on wp7 and memory card issues.
What we've learned from our tipsters and from documents culled from Microsoft, Samsung, and others is that the big issue is random access performance -- a figure that isn't taken into account in a card's class rating. Ironically, Microsoft discovered in its testing that cards with higher class ratings actually performed worse on Windows Phone 7 because the tweaks card manufacturers make to achieve high sequential throughput can actually hurt random access times. There's some rocket science involved here, but basically, it's a tradeoff and a bit of a gamble -- if a manufacturer tunes a card for a high class rating, it takes more time to access the first byte at a new location on the card because it's optimizing access for that area of memory, but once it does that, it can blast sequential bytes at very high speed. If you've got a lot of small reads or writes you need to make to different files at different locations in the card's memory, though, you really start to suffer. Cards with lower class ratings tend to spend less time optimizing sequential access prior to the first read / write operation, so it can move around the card (that is, access it randomly) much faster.
Click to expand...
Click to collapse
Source:
http://www.engadget.com/2010/11/17/windows-phone-7s-microsd-mess-the-full-story-and-how-nokia-ca/
azzzz said:
Could this be the reason why class don't matter on hd2 android? I mean even some class 4 & 6 have lag and sod problem. I pulled this bit from engadget. It's an article on wp7 and memory card issues.
Source:
http://www.engadget.com/2010/11/17/windows-phone-7s-microsd-mess-the-full-story-and-how-nokia-ca/
Click to expand...
Click to collapse
Obviously.
Been saying this for a while, myself - I have experimented, and I get SOD every time with my 16gb class 6 card, but rarely with my class 2 8gb, and never ever (and, tbh, better responsiveness overall) with my 2gb NON-HC card
enneract said:
Obviously.
Been saying this for a while, myself - I have experimented, and I get SOD every time with my 16gb class 6 card, but rarely with my class 2 8gb, and never ever (and, tbh, better responsiveness overall) with my 2gb NON-HC card
Click to expand...
Click to collapse
I hope so...my class 2 16gb will be here in a couple of days...i hope it's faster than my current 8gb class 4....
Update: my 16gb class 2 sandisk is here. Things have improved alot. Wake up is faster now with less lag, market download speed is faster now (10kb vs 100kb). Hopefully system performance will be better...

[Q] Performance tweaks?

Hi everyone,
could someone please explain me what all those "performance tweaks" are that the chefs are cooking into their roms?
i cant find anything about what they did... (search is offline for 20-30 min and other external searchengines also not find anything intressting)
i can see in some videos on youtube that the phone is faster - but why?
im using a class 6 16gb sdcard, so thats not be a problem i think...
can someone please enlighten me?
Thx!
whopper_g said:
Hi everyone,
could someone please explain me what all those "performance tweaks" are that the chefs are cooking into their roms?
i cant find anything about what they did... (search is offline for 20-30 min and other external searchengines also not find anything intressting)
i can see in some videos on youtube that the phone is faster - but why?
im using a class 6 16gb sdcard, so thats not be a problem i think...
can someone please enlighten me?
Thx!
Click to expand...
Click to collapse
ah somebody else noticed this, i believe they messed with some caches and that about somes it up, to be perfectly honest i dont see any where a noticable speed improvment could be made with regards to the UI so its all a bit of FUD if you ask me.
with regards to your speed, just because its a 16GB class 6 doesnt automatically make it work, infact, if its stable at all your on to a winner, ive got a class 2 thats quicker than a 4, its just luck of the draw, most slowdowns are SD related, try other cards, dont splash out because it might not even work but play around and see what you can get.
Most chiefs use these tweaks
Not really "performance", more "optimizations"
dazza9075 said:
with regards to your speed, just because its a 16GB class 6 doesnt automatically make it work, infact, if its stable at all your on to a winner, ive got a class 2 thats quicker than a 4, its just luck of the draw, most slowdowns are SD related, try other cards, dont splash out because it might not even work but play around and see what you can get.
Click to expand...
Click to collapse
Yeah, it's not the rated class that matters with wp7... the class just rates the sequential write speed. It's random access speed that matters with wp7 (or when running any os off a sd card)... it's the time it takes to access small random bits of data when to os needs it. Higher class cards actually tend to have lower random access speed because of the tweaks the manufacturer does to raise the sequential write speed.
To raise the sequential read and write speed, the higher class card will initialize the part of the chip thats being used before actually using it so it can then write or read to that part more quickly... but that takes time to initialize, and ends up taking longer if you are just grabbing one little bit of data from one part and a bit from another part, etc than it will take a class 2 card which doesn't do the initializing process and just starts grabbing the data when it's asked to.
Microsoft found this when testing sd cards for wp7... class 2 cards tended to work better than class 6 or 10 cards. It doesn't necessarily mean a class 6 or 10 card won't work, or that a class 2 card will definitely work, but more class 2 cards worked than class 6.
Also, since card makers don't really rate the random access speed, they don't keep the speed very consistent batch to batch... even with a card that's the same brand and class. You might get a Class 4 sandisk that works great, but someone else gets the exact same class 4 sandisk, but it was made a week later at the same factory and it may not work. The chips they use can be different from batch to batch, and they only watch and keep the sequential read and write speeds consistent.
Hopefully now that wp7 needs cards with good random access speed, card makers will rate that speed and sell cards good for wp7. And also when running android off SD, I've found that random access speed is what makes the biggest difference in performance. I remember reading about people having more lag in sd android builds with higher class cards... well that's why.
dazza9075 said:
ah somebody else noticed this, i believe they messed with some caches and that about somes it up, to be perfectly honest i dont see any where a noticable speed improvment could be made with regards to the UI so its all a bit of FUD if you ask me.
with regards to your speed, just because its a 16GB class 6 doesnt automatically make it work, infact, if its stable at all your on to a winner, ive got a class 2 thats quicker than a 4, its just luck of the draw, most slowdowns are SD related, try other cards, dont splash out because it might not even work but play around and see what you can get.
Click to expand...
Click to collapse
Your are right. i have to correct me - i got an 16 GB Class 2 SanDisk Card.
But why is there no info on how they speed up the MarktPlace that much? Its obvious that it is indeed faster - at least on Mobile network...
Sakem said:
Most chiefs use these tweaks
Not really "performance", more "optimizations"
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Yeah i see that - but, as you allready said, those are no perfomance tweaks ... but thanks for the hint...
zarathustrax said:
Yeah, it's not the rated class that matters with wp7... the class just rates the sequential write speed. It's random access speed that matters with wp7 (or when running any os off a sd card)... it's the time it takes to access small random bits of data when to os needs it. Higher class cards actually tend to have lower random access speed because of the tweaks the manufacturer does to raise the sequential write speed.
To raise the sequential read and write speed, the higher class card will initialize the part of the chip thats being used before actually using it so it can then write or read to that part more quickly... but that takes time to initialize, and ends up taking longer if you are just grabbing one little bit of data from one part and a bit from another part, etc than it will take a class 2 card which doesn't do the initializing process and just starts grabbing the data when it's asked to.
Microsoft found this when testing sd cards for wp7... class 2 cards tended to work better than class 6 or 10 cards. It doesn't necessarily mean a class 6 or 10 card won't work, or that a class 2 card will definitely work, but more class 2 cards worked than class 6.
Also, since card makers don't really rate the random access speed, they don't keep the speed very consistent batch to batch... even with a card that's the same brand and class. You might get a Class 4 sandisk that works great, but someone else gets the exact same class 4 sandisk, but it was made a week later at the same factory and it may not work. The chips they use can be different from batch to batch, and they only watch and keep the sequential read and write speeds consistent.
Hopefully now that wp7 needs cards with good random access speed, card makers will rate that speed and sell cards good for wp7. And also when running android off SD, I've found that random access speed is what makes the biggest difference in performance. I remember reading about people having more lag in sd android builds with higher class cards... well that's why.
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Thanks for the good explanation from the hardware point of view. but again all tweaks they made are software side.
Could it be that this is just a subjective speed improvement?

[Q] Is microSDHC Class 10 compatible with HTC HD2?

I ordered a ADATA 8GB MicroSDHC Class 10 memory card for my HTC HD2. I'd like to know if it will work well on my phone since the transfer is so high. I'm asking this because I want to use a SD version on android.
Thank you in advance for the answer!
When i asked my friend who was the Sales Director of Sandisk Australiasia, he said that the read and write speeds of the supplied Class 2 was more than enough, since these Class 2 is the minimum guaranteed write speeds for that card.
Personally, i'd like to use a faster card, but i think that the key here is the quality of the card over the speed. Im using android over SD and dont mind the negligible lag.
Perhaps someone who has tried a faster card can comment on Droid on SD, as NAND speed offers the fastest, but without the flexibility.
GLO said:
When i asked my friend who was the Sales Director of Sandisk Australiasia, he said that the read and write speeds of the supplied Class 2 was more than enough, since these Class 2 is the minimum guaranteed write speeds for that card.
Personally, i'd like to use a faster card, but i think that the key here is the quality of the card over the speed. Im using android over SD and dont mind the negligible lag.
Perhaps someone who has tried a faster card can comment on Droid on SD, as NAND speed offers the fastest, but without the flexibility.
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I found a really old thread where people were saying it is fully supported. Thanks for the answer! I want to use android on the sd too because I don't really want to risk messing up my phone with a rom install.
It's been around for ages that the speed of the SD doesn't matter for SD android.
what matters is the access time, here's a thread for benchmarks:
http://forum.xda-developers.com/showthread.php?t=1048649
the smaller the access time the better. in other words, you might get a class 10 card with long access time, and a class 2 with short access time, the class 2 will perform better overall (faster system loading, etc). but when you copy large files the class 10 will be faster.
meaning: for running android on SD you need a faster access time, and each millisecond counts.
[edit] forgot to say that random read and write speeds play a good role as well.
I use PNY 32GB class 10 MicroSD card in my HD2. No problem at all. Phone is only one week old and haven't installed any cooked ROM yet so 32GB card on stock ROM.
yes, a class 10 would work perfect with stock or custom windows ROMs. and with NAND android to some point.
I'm talking about SD android which, in case you haven't read the previous posts, he wants to run a build on his SD. and that's where the class 10 cards start to look bad. they mostly have slower random read/write speeds. In usage terms that's: lags, lags, errors, and more lags.

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