[Q] SD Card Class Question - Epic 4G General

Ok.... So I have a 32gb Class 4 SD Card. When I went from the stock 16 class 6 card I noticed a speed difference... And well.. It has finally got to me... I am looking at going class 10 but I am wondering if anyone has done an upgrade like this and has any input.
I understand the class number is directly related to the speed in mbps but I guess what I am really curious about is will the epic write/read the card at faster speeds (than 6 [which is stock]) reducing my lag spikes in applications, pictures (taking and viewing), and in gallery 3d(While creating thumbnails [I have noticed this has slowed down the MOST])
For anyone who is interested I am looking at getting this SD card (Please note that I have nothing to do with this seller on amazon and am purely asking for opinions)...
amazon /Patriot-Signature-MicroSDHC-Memory-PSF32GMCSDHC10/dp/B004H8FTCU <----- Insert .com
Again I do know the pure fact that a class 10 offers more speed than class 6 and 4 but is the epic capable of using that speed?
Thanks in advance!

I don't know if our hardware will push the speeds of a class 10, that's not saying you cant use it, just saying you likely won't get those speeds out of it. Most of the time you can't get that much out of one even if the hardware will support it. I'd be willing to be 60% of cards out there are over classed or numbers are inflated from actual production chips.

"Stock card" was a Class 6? My launch day Epic came with a Class 2...

crzyrider250 said:
"Stock card" was a Class 6? My launch day Epic came with a Class 2...
Click to expand...
Click to collapse
My 3 month old Epic also came with a Class 2. LOL - popping it out with the phone running caused my Phone to reboot (Bonsai).

Kcarpenter said:
I don't know if our hardware will push the speeds of a class 10, that's not saying you cant use it, just saying you likely won't get those speeds out of it. Most of the time you can't get that much out of one even if the hardware will support it. I'd be willing to be 60% of cards out there are over classed or numbers are inflated from actual production chips.
Click to expand...
Click to collapse
Yes. Our hardware can. I have done tests transferring files from my computer to the USB card via my phone and it is extremely fast. Camra speed has also dramatically increased if you are taking HD photos. Camcorder speed also increased. But I was going from a stock class 2 16gb that came with the phone to a class 10... So coming from a Class 6, I dunno how much of an increase that would be.

Related

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"
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
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?

SD Card benchmarks

Hi guys,
I'm curious about the speed of the bundled microSDHC card. I just benchmarked it with SD Tools and consistently get around 6-8MB/s writes and around 17MB/s reads, and the label says Class 2 so it's performing way faster than rated (more like a Class 6). I'm running jt's CM7 Alpha 3 if that makes any difference.
I'd appreciate it if people would post benchmarks of their bundled cards or any other SD cards that they've bought for comparison. Thanks!
Edit: 8MB/s writes also reported by Antutu System Benchmark, so it might not be a fluke. Also, when transferring files via USB I'm getting 7.5MB/s too. This is crazy! I'm actually looking at getting a cheap 32GB Class 4 card tomorrow but it seems like it'll probably be slower... Although class rating is just a minimum write speed, I doubt most cards have such fast write speeds, especially when they're marked Class 2.
Write: 7.7
Read: 28.9 / 21.2
Pretty impressive for a class 2.
Sent from my SCH-I500 using XDA App
Though I have a 32 class 4, the card that came with the phone consistently transferred just as fast, if not faster, than it. I was always impressed by it.
I too ended up buying my own class 4, but not because the SD card that came with the phone was slow, as you guys know, it is quite fast. My problem was I was burning through them. I burned through three in about three months and they got sick of giving me new ones...lol. Class 4 now for about 2 months, and not a problem, and honestly about the same speed, so it seems.

is this normal for a class 4 sd card?

i bought an 8gb sandisk micro sd card quite a few years back before my first smartphone. didnt know it was a class 4. didnt know about that back then.(finally looked at the card itself just yesterday lol)
anyways, ive had it in my wifes hero and i was using the stock evo one, found out about sd tools and did some tests. stock evo sd was doing about 5MB/s write and about 10MB/s read. i noticed on hers she was getting about 7MB/s write and about 10-12MB/s read. kicked myself in the butt for accidently letting her have the faster one(she doesnt care)
well i swapped em. 12.8MB/s(avg 10-11MB/s) write and 20+MB/s read
i always thought 1 MB/s per class number
Is this test accurate? Did same test on a class 10 card and got the same results. Is the EVO able to transfer information at that rate to the sd card to achieve the above test results?
the class.. is to mark batches made a certain speed... but to the lowest possible deviation.
i am sure that in the same batch.. there are some that are not as fast.. and some are faster. you got lucky with this one.
also maybe.. sometimes manufactures just make a huge production line of product... but mark some a lower speeds... cost is the same for the manufacturer.
mark some class 4, some class 6.
in the past.. Intel has done this with a few CPUs....

Class of SD card

Did my Mango update fix the "class" issue for Micro sd cards. Can I use a class 10 card now?? Or is this a DVP issue?
slight22 said:
Did my Mango update fix the "class" issue for Micro sd cards. Can I use a class 10 card now?? Or is this a DVP issue?
Click to expand...
Click to collapse
The class is not a DVP specific issue. It's a MS WP7 OS level issue/limitation. Class 2/4 is the max recommended (not by MS, but by user experience).
Read here for details on the card class.
Has anyone ever tried a class 10 just to see if it would work? I only ask because i can buy a class 10 for only 10 dollars more than a class 4.
slight22 said:
Has anyone ever tried a class 10 just to see if it would work? I only ask because i can buy a class 10 for only 10 dollars more than a class 4.
Click to expand...
Click to collapse
I would save the ten bucks and get something that's more widely accepted to work.
FWIW a Class 10 is only worthwhile if you're constantly dragging heaps of files (or big files) backwards and forwards onto/from it.
The Class signifies the sequential transfer speed. Manufacturers tweak the random access times to boost sequential throughput. Random access times are things like saving camera photos to the SD card, loading the gallery, loading the music collection, running Apps from SD etc.
You will sacrifice everyday 'zip' to gain good throughput for big file transfers. Class 10 cards, to me at least, are just not worth the trouble. I'd rather have good speed in everyday tasks than good speed doing a card dump back and forth. YMMV of course
juzz86 said:
I would save the ten bucks and get something that's more widely accepted to work.
FWIW a Class 10 is only worthwhile if you're constantly dragging heaps of files (or big files) backwards and forwards onto/from it.
The Class signifies the sequential transfer speed. Manufacturers tweak the random access times to boost sequential throughput. Random access times are things like saving camera photos to the SD card, loading the gallery, loading the music collection, running Apps from SD etc.
You will sacrifice everyday 'zip' to gain good throughput for big file transfers. Class 10 cards, to me at least, are just not worth the trouble. I'd rather have good speed in everyday tasks than good speed doing a card dump back and forth. YMMV of course
Click to expand...
Click to collapse
I kinda knew what the differences was, but thank you for the refresher
I actually did buy a class 4 card here yesterday and it should be here tomorrow, or amazon says. But i was more asking to see if it had been done.
Thx
slight22 said:
I kinda knew what the differences was, but thank you for the refresher
I actually did buy a class 4 card here yesterday and it should be here tomorrow, or amazon says. But i was more asking to see if it had been done.
Thx
Click to expand...
Click to collapse
Lol, sorry mate. I may have misinterpreted your question a little!
Appreciate the 'thanks' though!
I'm using a class 10 card, no issues so far fixed all the problems that I had with the original one plus it's much faster

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