Related
if i have a faster sd, would the android be snappier??
Some will say this is the case, others not so much. So, I would suspect that your experience will vary as well.
alancai said:
if i have a faster sd, would the android be snappier??
Click to expand...
Click to collapse
You have to clarify... faster in what way? Sequential write speed? (which is what the class ratings refer to) Or random read/write/access speeds? (Which tend to slow down when sequential speeds are increased)
Since we are running android off the SD, our SD cards are going to be accessing many different areas of the SD' NAND chip to read or write many small files quickly. So what is most important in a SD card for us is going to be the random read/write speeds and access time.
I could explain further and explain why the higher class cards have slower random access speeds, but I've explained in so many posts, and people aren't usually interested, and I'm tired and have other things to do so I'm wrapping this post up.
So to answer you question... if you're asking if a higher class card will make android snappier, answer is no... it may cause it to lag and slow down, actually. Go for a high quality class 2 or 4 Sandisk card... they are good at keeping good, consistent random access speeds... I have 8 Sandisk class 2 or 4, and all work very well running android off of.
I don't think you can make this phone any faster.
zarathustrax said:
I could explain further and explain why the higher class cards have slower random access speeds, but I've explained in so many posts, and people aren't usually interested, and I'm tired and have other things to do so I'm wrapping this post up.
Click to expand...
Click to collapse
Yeah, I'd stop posting that NoDoz if no one read it. Point me to that link please. I am going to do the ultimate experiment anyway: 32GB Class 10. We'll see if we can make the baby scream and cry for mercy.
You can always try playing around with the sector size; I dropped the sector size on the card I use to 1 Kb, and it feels a little better (it was 8 kb before). It sucked at 512 bytes, though. I got a lot of corruption. At 1 Kb sector size, I only get two .chk files after a scan now; one is 1 kb and the other is 2 kb. At 512 bytes, I got like 100 corrupted files after a scan, and some were large.
Does it matter the capacity, much less class or should that theoretically work for every microSD?
No idea; the card I'm using now is a 1 GB sandisk. I used to just use my regular 16 GB card, but got tired of having to scan it all the time; it took too long. Sector size is just one other thing to play with, I guess. You have less wasted space with smaller sector sizes, but benchmarks usually show slower writing speeds. I just figured smaller might be better, because so much stuff is being written all over the place all the time.
Hi, i bought some days ago an 8GB class 10 micro sd card, hoping it would speed up my phone (i was using app2sd+ with Kyrillo's ROM v7.1).
I didn't notice any diference compared to my old 4GB class 2 card, so i installed SD Tools app to test the speeds, and i realized all the cards i put in my phone get 4MB/s as the maximun write speed, i tried many different sd cards, class 2 and 10 and there's no difference. Then i tried the same cards in my girlfriend's Galaxy Ace and the speeds were much higher, 7~12 MB/s write speed.
I thought it was a rom problem, so i backed up with Titanium Backup and flashed a stock ROM (JPM), but the speeds remain the same (around 4 MB/s for writing), i also tried changing the buffer size from 128kb to 1024, 2048, 4096 with "SD Booster" and "SD Speed Increase" apps, but no good results...
Could my phone be faulty?
Is there any configuration i can try to make my sd card faster? any command line?
What are the speeds you reach with "SD Tools" and classes of your SD card?
Best Regards!
I'm not sure, but I think there's nothing you can do....
Mine is a 16GB class 6 and it's the same, whatever I try. Before had 8GB - was the same.
Whatever I wrote into the 'read ahead buffer'...
But maybe anyone else has an idea?
Try changing the buffer to 0 as sometimes that works.
Sent from my GT-I5800 using XDA App
dilzo said:
Try changing the buffer to 0 as sometimes that works.
Click to expand...
Click to collapse
TNX for the tip, but unfortunately SAME RESULT...
i also get the same speeds..
i think thats a bug with sd tools.
By the way has any one tried data2sd/apps2sd v3? do you face lags?
also do you people have SD or SDHC
I belive that sdtools has a bug. Or is seriously faulty. I have 16GB class 2 sdcard and sdtools claims that my read and write speeds are equivavlent to class 6 card (values range from 6.x/6.x to 8.x/7.x, write/read, respectively (depending on read_ahead_kb values). And I know for a fact that this really cheap sdcard does not have such performance. You can try antutu benchmark, free app on market, which provides a bit more accurate results plus you can select what to benchmark. My card gets 3.0MB/s read and 2.0 MB/s write with default buffer values. Which is more accurate than sdtools. Especially because disks (any kind) usually have higher read rate than write rate (because it is easier to read data than to write it and 'cause we usually perform much more reading than writing, so it is optimized for read operations).
mrvek said:
I belive that sdtools has a bug. Or is seriously faulty. I have 16GB class 2 sdcard and sdtools claims that my read and write speeds are equivavlent to class 6 card (values range from 6.x/6.x to 8.x/7.x, write/read, respectively (depending on read_ahead_kb values). And I know for a fact that this really cheap sdcard does not have such performance. You can try antutu benchmark, free app on market, which provides a bit more accurate results plus you can select what to benchmark. My card gets 3.0MB/s read and 2.0 MB/s write with default buffer values. Which is more accurate than sdtools. Especially because disks (any kind) usually have higher read rate than write rate (because it is easier to read data than to write it and 'cause we usually perform much more reading than writing, so it is optimized for read operations).
Click to expand...
Click to collapse
antutu give me 3.x and 4.x for write and read speed respectively!!
8gb class 10
That is odd. Do you have a card reader? Maybe you can bench from pc and see the results. I have only 2 sdcards, both class 2 and the results I get are to be expected from class 2 cards. There is also possibility that it is a low quality component. If you feel like it try to investigate, get cards info like serial, model and manufacturer and see what you'll discover. Nowadays people are selling everything claiming it to be a better than actually is. I remember reading tests regarding SD 's where they said that same card type from same manufacturer performed about 10 times worse just because one was.made in China and the other in taiwan, or something like that. I personally would do some research but it's up to you.
mrvek said:
That is odd. Do you have a card reader? Maybe you can bench from pc and see the results. I have only 2 sdcards, both class 2 and the results I get are to be expected from class 2 cards. There is also possibility that it is a low quality component. If you feel like it try to investigate, get cards info like serial, model and manufacturer and see what you'll discover. Nowadays people are selling everything claiming it to be a better than actually is. I remember reading tests regarding SD 's where they said that same card type from same manufacturer performed about 10 times worse just because one was.made in China and the other in taiwan, or something like that. I personally would do some research but it's up to you.
Click to expand...
Click to collapse
well i did a bench mark from laptop's card reader.. it was way over 18 mbps.. cancelled the benchmark in the process as it was taking too long.. but half way read speed was definitely above 18mbps.. Also my sdhc's manufacturer is transcend. I hope this company wont betray us!!
well, in that case it might have to do with phone configuration/programming. Maybe devs could figure out why the phone does not utilize full potential of the sdcard. Perhaps low ram, (relatively) "slow" cpu, something...
mrvek said:
well, in that case it might have to do with phone configuration/programming. Maybe devs could figure out why the phone does not utilize full potential of the sdcard. Perhaps low ram, (relatively) "slow" cpu, something...
Click to expand...
Click to collapse
Good point. Hope some dev is listening!!
I have the same problem.
Samsung Galaxy 3 GT-i5800, Android Froyo firmware v2.2 build XWJPL.
I tested with two class 10 microSD cards, quality ones, but got poor transfer rates.
card1: Transcend 8GB MicroSDHC Class10 (TS8GUSDHC10) - up to 20 Mb/s
card2: Samsung 8GB SDHC Plus Class10 (MB-MP8GA/EU) - Read max. 24 Mb/s, Write max 21 Mb/s
Samsung 8GB cl10 test result (SD Tools app): Write: 4.4 Mb/s; Read 5.1 Mb/s
The card write speed should be higher than 10 Mb/s
Thought I would share this awesome deal. Been using for the past 2 days and it's a great product combo for a great price. here's the link:
SanDisk 32 GB SD HC micro SDHC Class 4 Flash Memory Card with Everything But Stromboli (tm) Card Reader
Product Features and Technical Details
Product Features
Available capacities: 2 GB*, 4 GB, 8 GB, 16 GB, and 32 GB
Seamless speed and performance with microSD/SDHC compatible devices
Class 4 Speed performance rating (based on SD 2.0 Specification)
Tested under the most extreme conditions
Technical Details
Brand Name: SanDisk
Model: 32G_TF_c4_San_R4OREBS
(Gasp) Nice find! I think I might just order one of these tonight!
DAYUM
Thank you! definitely getting one of these babies
yea pretty great deal. the usb card reader makes transferring everything from the old sd card quicker too...you dont have to put it on your pc THEN onto the new card. you just put everything straight from the phone onto the new 32gig card by sticking it into the usb reader. i love you amazon.
I am returning mine. Ordered two, and after the first one failed twice, I didn't bother with the second one. The reader is also clumsy - it's very tight and you have to push the card in much harder than I would usually do with other readers. Keep in mind that most of the time, it's the insertion and removal where cards get damaged, so I wouldn't even use the reader with any other cards.
Second try after formatting with Easeus:
The media is likely to be defective.
26.9 GByte OK (56528894 sectors)
1 KByte DATA LOST (2 sectors)
Details:0 KByte overwritten (0 sectors)
0.5 KByte slightly changed (< 8 bit/sector, 1 sector)
0.5 KByte corrupted (1 sector)
0 KByte aliased memory (0 sectors)
First error at offset: 0x0000000067b7dbf0
Expected: 0xf765e38b895548f0
Found: 0xff4621f7695548f6
H2testw version 1.3
First try right out the envelope:
The media is likely to be defective.
24.3 GByte OK (51159038 sectors)
1 KByte DATA LOST (2 sectors)
Details:0 KByte overwritten (0 sectors)
0 KByte slightly changed (< 8 bit/sector, 0 sectors)
1 KByte corrupted (2 sectors)
0 KByte aliased memory (0 sectors)
First error at offset: 0x0000000386d047e0
Expected: 0xc6184f899a694fe0
Found: 0x2bae31c618694fe0
H2testw version 1.3
WOW great price I thought the 40 bucks I paid was a deal
lost_ said:
I am returning mine. Ordered two, and after the first one failed twice, I didn't bother with the second one. The reader is also clumsy - it's very tight and you have to push the card in much harder than I would usually do with other readers. Keep in mind that most of the time, it's the insertion and removal where cards get damaged, so I wouldn't even use the reader with any other cards.
Click to expand...
Click to collapse
I received mine today, so far I've had no issues copying pictures/movies to it from my old 16gb card. Although, I have to agree about the card reader, I couldn't get the 32gb card to fit at all :c the 16gb fit fine though... but eh, my usb cord worked fine for transfering everything
Sent from my SPH-D700 using XDA App
Unless you run a verify like with h2testw or go through every single file, you can't tell if your copy was good because Windows can be fooled into thinking everything was copied. I don't use any memory stick or card that doesn't pass h2testw.
I have another 32GB SanDisk class 4 that I bought from Amazon but a different seller for $28. That card is good.
Well my movies play fine so...? :| I think you just got unlucky man Dx
Sent from my SPH-D700 using XDA App
I got mine and used it with the card reader that came with my phone and it worked GREAT! Just ordered a second one for my wife's phone. I didn't know the orange gadget was a card reader, I thought it was a usb thumb drive. I'll try it next.
Just tried the orange card reader...works fine.
Damnn sorry bout the issues lost. I've been using the card for a week with zero issues and put about 13gb onto it using the card reader when I first got it.
Sent from the Epoch
No biggie and not your fault. Stromboli replied that I can send them back for refund (at my cost, but that's the cost to play the game).
h2testw reported that the corruption started occurring at around 24 to 26gb. Depending on your card, if your usage is still below that, you may or may not run into any issue. If you're not familiar with h2testw, it writes a bunch of files, each up to 1GB, then reads them back to verify that each was written correctly. It failed twice on me, so it is a sure sign of a defective card or possibly even fake, not sure which.
FrankyFiggz27 said:
Damnn sorry bout the issues lost. I've been using the card for a week with zero issues and put about 13gb onto it using the card reader when I first got it.
Sent from the Epoch
Click to expand...
Click to collapse
IronReaver17 said:
Well my movies play fine so...? :| I think you just got unlucky man Dx
Sent from my SPH-D700 using XDA App
Click to expand...
Click to collapse
IronReaver17 said:
I received mine today, so far I've had no issues copying pictures/movies to it from my old 16gb card. Although, I have to agree about the card reader, I couldn't get the 32gb card to fit at all :c the 16gb fit fine though... but eh, my usb cord worked fine for transfering everything
Sent from my SPH-D700 using XDA App
Click to expand...
Click to collapse
You're both doing it wrong, sure you may be able to get 16GB or less data onto the card...but you should really see if it can handle it's max rated capacity by verifying with h2testw.
Sorry I may be coming off as rude but it's better to catch this problem early before you reach a point where you start corrupting files even though it seems like everything is transferring in fine...I've gone through many fake 32GB cards, and I had to manually verify they were crap before I discovered h2testw.
lost_ said:
No biggie and not your fault. Stromboli replied that I can send them back for refund (at my cost, but that's the cost to play the game).
h2testw reported that the corruption started occurring at around 24 to 26gb. Depending on your card, if your usage is still below that, you may or may not run into any issue. If you're not familiar with h2testw, it writes a bunch of files, each up to 1GB, then reads them back to verify that each was written correctly. It failed twice on me, so it is a sure sign of a defective card or possibly even fake, not sure which.
Click to expand...
Click to collapse
+1, they haven't come close to the typical failure point of these "24GB" cards to have them fail, *yet*
Wah I'll have to do that test you guys keep talking about when I get home
Sent from my SPH-D700 using XDA App
IronReaver17 said:
Wah I'll have to do that test you guys keep talking about when I get home
Sent from my SPH-D700 using XDA App
Click to expand...
Click to collapse
Let us know how it goes, remember you're not only helping yourself, but also your peers here on XDA who can make a better purchasing decision with your findings, as well as Lost's. so far 2 cards were duds, maybe those were the only ones, or maybe they all will be bad.
We can't let anyone else get conned if it turns out they all are phonies, and everyone affected should get their money back and report the issue to Amazon (also check and make sure it's not just one 3rd party seller that's doing it through Amazon)
iviyth0s said:
Let us know how it goes, remember you're not only helping yourself, but also your peers here on XDA who can make a better purchasing decision with your findings, as well as Lost's. so far 2 cards were duds, maybe those were the only ones, or maybe they all will be bad.
We can't let anyone else get conned if it turns out they all are phonies, and everyone affected should get their money back and report the issue to Amazon (also check and make sure it's not just one 3rd party seller that's doing it through Amazon)
Click to expand...
Click to collapse
Will do... looks like this test is going to take awhile Dx but if its for the greater good... LOL
Edit: Ok, I did the test. It took about an hour and a half, and that's because it only wrote/verified 17 gigs. I know, I know. I should've formatted the sd card first. But I tested each movie (ten total) and fast-forwarded through them all. They all played fine.
Warning: Only 17204 of 30424 MByte tested.
Test finished without errors.
You can now delete the test files *.h2w or verify them again.
Writing speed: 3.52 MByte/s
Reading speed: 18.3 MByte/s
H2testw v1.4
I don't know if I copied the right info >.< but yeah... I'll format my sd card and do it again if you guys want. I don't really want to though, since that'll take up quite a bit of my time...
**** i didn't even know about that test. I'm gonna be extra careful now and try to stay under 24gb and be extra cautious when i get there
Sent from the Epoch
IronReaver17 said:
Will do... looks like this test is going to take awhile Dx but if its for the greater good... LOL
Edit: Ok, I did the test. It took about an hour and a half, and that's because it only wrote/verified 17 gigs. I know, I know. I should've formatted the sd card first. But I tested each movie (ten total) and fast-forwarded through them all. They all played fine.
Warning: Only 17204 of 30424 MByte tested.
Test finished without errors.
You can now delete the test files *.h2w or verify them again.
Writing speed: 3.52 MByte/s
Reading speed: 18.3 MByte/s
H2testw v1.4
I don't know if I copied the right info >.< but yeah... I'll format my sd card and do it again if you guys want. I don't really want to though, since that'll take up quite a bit of my time...
Click to expand...
Click to collapse
I'd test it completely formatted/empty myself, just to be sure but hopefully you got a good egg. Sucks it's not making it's class 4 standard, but the read speeds are nice.
FrankyFiggz27 said:
**** i didn't even know about that test. I'm gonna be extra careful now and try to stay under 24gb and be extra cautious when i get there
Sent from the Epoch
Click to expand...
Click to collapse
Or just run the test with the card empty
Just a heads up, Fry's usually has a Samsung 32GB Class 10 micro sdhc for $34 I believe, I'll try to post a link here later, in case someone is looking for a Class 10 card.
Edit: http://www.frys.com/product/6786695
Looks like it's back on sale, I bought one a month ago, and it's great
Sent from a Galaxy far, far away . . .
damn, those cards at frys look nice. Lol, so if my phonegot wet it would be toast but my sd card would be fine.
Hello,
I'm totally sad about my situation with my SD Card. I have a SanDisk Mobile Ultra microSD Class 6 16GB Card for my HTC Desire. I used it with MIUI Gingerbread and MIUI ICS and I'm installing Sandvolds ICS yet to look if I have trouble with MIUI only.
My problem is that I get always FC and Crashes. I have my old SD Card from PNY Class 10 with 8Gig and I it seems that I haven't any problems with this card. But there is a disadvantage with this SD Card: it is totally slow. I have to wait always some seconds until the app starts and this is really annoying if you want to look fastin the browser or something like that.
So, can you recommend any good SD Cards with 8-16GB memory? I don't know why this SanDisk Card makes so much trouble. I thought Sandisk is one of the best companies in memory cards?
Thanks
Greets,
Burak
I bought a Hama 16GB Class 10 micro SD. Haven't had any problems with that.
http://www.hama.de/00108088/hama-mi...-+-adapter-photo?bySearch=108088&searchMode=1
Regarding slow app starts. Are you using some sort of A2SD and have you moved APPDATA to SD?
--
I never had any problems with SanDisk, too.
Maybe Your SD-Card is broken?
Just try another Class10 SD-Card from SanDisk...
Try to format sd card with gparted (ubuntu) or partition magic (windows 7)
then
try to look for bad drive sectors (scan disk or every defrag tool).
Execute a microsd stress test for 1 hour at least.
If everything is ok, try to partitioning with Clockworkmod recovery.
What are you guys buying class 10 cards for? Those are designed for high definition video recording. You should be using class 4 or 6 with android phones, always. Any apps that need to read and write small chunks of data at high speed will get choked by class 10.
Sent from a galaxy far, far away
SJAirWolf said:
If everything is ok, try to partitioning with Clockworkmod recovery.
Click to expand...
Click to collapse
dont use CWM its pretty bad at partitioning. u recommended gparted so u shoulda just left it at that. 4ext recovery is the best recovery for partitioning sdcards and the best recovery
Sent from my HTC Desire
I'm using a Samsung 16GB Class 10 micro SD...i have no problem..realy fast!
CrystalDiskMark
Hello,
have you tried 'CrystalDiskMark' for benchmarking the MicroSD-Card? It runs under Windows and has a benchmark for 4k blocks (which are important for ext3/ext4 file systems).
Yesterday, my new SanDisk MicroSD card arrived and i tested all of my Cards. The results (all values in MB/s, the 4K entries are the interesting ones) are
SanDisk 16G Ultra Class 10 Micro SDHC (my new card)
Read: 18.76
Write: 11.92
Read 4K: 3.2
Write 4K: 1.54
SanDisk 4G Class 4 Micro SD (this card was originally delivered with my HTC Desire)
Read: 10.59
Write: 3.05
Read 4K: 0.9
Write 4K: 0.47
Tanscend 16G Class 4 Micro SDHC
Read: 18.65
Write: 4.85
Read 4K: 2.64
Write 4K: 1.26
Tanscend 16G Class 10 Micro SDHC (my actual used card)
Read: 16.47
Write: 16.07
Read 4K: 3.4
Write 4K: 0.027
As you can see on the last card, writing can be very slow on small blocks. I think, the internal block size on the most bigger class 10 cards is not optimized for small, but for big blocks. These behaviour is also documented here: http://forum.xda-developers.com/showpost.php?p=29365127&postcount=6827
Also, the partitions must be aligned to 4k. I did this by using the Linux fdisk for partitioning directly (sorry, all in german)
# fdisk /dev/sdf
Befehl (m für Hilfe): p
Disk /dev/sdf: 15.9 GB, 15931539456 bytes
64 Köpfe, 32 Sektoren/Spur, 15193 Zylinder, zusammen 31116288 Sektoren
Einheiten = Sektoren von 1 × 512 = 512 Bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Gerät boot. Anfang Ende Blöcke Id System
/dev/sdf1 2048 28494847 14246400 c W95 FAT32 (LBA)
/dev/sdf2 28494848 31116287 1310720 83 Linux
Click to expand...
Click to collapse
As you can see, the sector size is 512 Byte, so for a 4K alignment, the sector number must be divisible by 8.
Simon
I'm using sandisk 16GB class 6 and still okay for desire
Currently i'm using a "16 GB Poppstar Micro SDHC Class6" and it's working fine as a sd-ext in ext3. Cheap and good value for the money.
Samsung Class10 Micro Sd, partitioning with 4ext recovery. Everithing went fine and fast.
Transcend 16gb class 6 do the best job for me but I usually format the card with 4ext before flash new rom
Hello,
I'm sorry that I answer only now. I forgot this problem with my sd card totally . Thanks for the recommendation, I will look for a Samsung SD Card or another SanDisk SD Card Class 4. Maybe it has some problem with this Ultra MicroSDHC cards....
I use 4ext recovery touch and did the partition with it. I checked the alignment too. I tried to partition the sd card with GParted by myself, but it failed as I wanted to install the ROM. I don't know what matter was.
Thanks.
vBurak said:
Hello,
I'm sorry that I answer only now. I forgot this problem with my sd card totally . Thanks for the recommendation, I will look for a Samsung SD Card or another SanDisk SD Card Class 4. Maybe it has some problem with this Ultra MicroSDHC cards....
I use 4ext recovery touch and did the partition with it. I checked the alignment too. I tried to partition the sd card with GParted by myself, but it failed as I wanted to install the ROM. I don't know what matter was.
Thanks.
Click to expand...
Click to collapse
You should look for a Class 10 (x150, up to 20MB/s read and up to 15MB/s write), mine emtec 8GB has been bought for $15 with adapter and 5 years manufacturers warranty. Working great in Desire
I have some Kingston 16 Gb class 4 micro SDHC and it's ok even if I use data2sd, int2ext and such.
nonline said:
You should look for a Class 10 (x150, up to 20MB/s read and up to 15MB/s write), mine emtec 8GB has been bought for $15 with adapter and 5 years manufacturers warranty. Working great in Desire
Click to expand...
Click to collapse
No, class 10 is designed for recording high definition video. Class 4 and 6 are the most compatible with the Android operating system, and the apps used by it.
Try reading the thread, or actually doing some research before you attempt to make recommendations.
Sent from a galaxy far, far away
I have now Samsung Class 10 16GB Micro SD Card and it works well. I use some modded a2sd script (lx2sd or something i don't know) and everything is on the sd card except dalvik cache. If I open some apps I have to wait 2-3 seconds but it's no big deal.
I didn't find any class 6 sd card from samsung, so I took the class 10. random 4 write was really low like 0,03 mb/s but now i have it and I don't care anymore .
captain67 said:
No, class 10 is designed for recording high definition video. Class 4 and 6 are the most compatible with the Android operating system, and the apps used by it.
Try reading the thread, or actually doing some research before you attempt to make recommendations.
Sent from a galaxy far, far away
Click to expand...
Click to collapse
That is not entirely true. That random 4k read/write speed is just a benchmark. Who told you that the .dex files are scattered in random blocks on the sd-ext? 99% of the time they are not. That's where the sequential speed kicks in and that's why anyone who uses a class10 over a class 4 sees a huge improvement in responsiveness.
Plus, no lag on 720p recording with sense roms. That's just a bonus.
I'm using a Transcend 16 GB class 10 card. The card is working very good as sd-ext with ext4 partition
I dabble in microprocssors such as AVRs and such and they have a flash life of around 40,000 flashes before they are dead.
I was wondering what the "Flash Life" of tablets are. Will there be a time when they will finally burn out?
Now 40,000 flashes are more than anyone would be able to flash this device in a reasonable tablet lifetime before it is obsolete. Just wondering what the number would be.
Since all flash is in the eMMC, firmware flashes count as normal writes. The eMMC is using MLC or even TLC, so we are talking about a few 1000 writes for each cell, distributed over the full capacity by the eMMC's FTL for wear leveling. So let's say 64 GB * 1000 = 64 TB total writes, but this has to be divided by the write amplification factor. It's a bit hard to estimate write amplification due to the primitive controller and FTL - it could even be up to 1000 in the worst case of all random 4 kB writes (each would need to rewrite a full erase block). More realistic may be a factor of 5 to 20 - so let's guess 64 TB / 10 = about 6 TB written in total.
Fascinating question:
Only thing I see are claims from Hynix (formerly Hyundai) that their recent SSD and NAND memory has up to 2,000,000 hours MTBF.
Don't see how this claim would hold water in a real sense....just a calculated guess on the manufacturers part.
Hard to tell when write failure will occur at the lower voltage levels used for eMMC's.
I'd think 40 to 60,000 hours would be more in line.
Thanks _that.
I should be able to burn this thing out in a month or so. LOL J/K.
When flashing does the eMMC get totally erased before writing or are just the addresses used in the code written to the chip? This would determine the life of the chip as a total erase would shorten the life. Am I correct in assuming this or is my understanding all wrong?
Is there a data sheet available for the eMMC used in these devices or is it an ASUS trade secret?
Thats OK, are you talking about actual hours flashing or just the run time of the chip?
Dee Envy said:
Thanks _that.
I should be able to burn this thing out in a month or so. LOL J/K.
When flashing does the eMMC get totally erased before writing or are just the addresses used in the code written to the chip? This would determine the life of the chip as a total erase would shorten the life. Am I correct in assuming this or is my understanding all wrong?
Is there a data sheet available for the eMMC used in these devices or is it an ASUS trade secret?
Thats OK, are you talking about actual hours flashing or just the run time of the chip?
Click to expand...
Click to collapse
Ah I was looking at time before failure on Hynix eNAND.
That 2 million hours seemed a bit way out.
Just searching around for a data sheet on the Hynix M26M64002BNR is turning into a dead end.
Everything goes to an HY27 number looks like the chip has been replaced from the maker.
I was hoping I could find actual read\write white paper for the chip.
Dee Envy said:
When flashing does the eMMC get totally erased before writing or are just the addresses used in the code written to the chip?
Click to expand...
Click to collapse
Flash memory has 3 operations: erase, write, read.
Magnetic storage has only 2: (over)write, read.
So, to overwrite something in flash memory, an erase operation is always necessary. And this operation has a granularity in the megabyte range - that's why random 4k writes are so slow.
If you want to know how flash cards work, read this:
https://wiki.linaro.org/WorkingGroups/KernelArchived/Projects/FlashCardSurvey
Thanks for the link, _that.
There's some good reading there.:good: