SD Card is So Freaking Slow! - X Style (Pure) Q&A, Help & Troubleshooting

I have a PNY U3 Turbo Performance 64GB High Speed MicroSDXC Class 10 UHS-I, up to 90MB/sec Flash Card. It seems to get slower with time. I mean it is literally taking me like 60 seconds to delete a few pictures. The card is formatted to portable storage. I only store music and photos on it. Reformatting offered no improvement. It is borderline unusable.
So, I benchmarked and found that my read speed is about 59 mb per sec and my write speed is 4.4 mb per sec. I can live with the read speed but the write speed is horrible. What gives?

How many pictures are you talking about, and how large are they?

128KB clusters?
I found trying to use 4K clusters in exfat was resulting in the same slowness. Reformatted to 128KB clusters and it flys (~20MB/s write ~70MB/read). Sandisk ultra plus 64GB.

I have this issue as well I have one of the fast Samsung cards. First few months worked great super fast but now takes a while to carry over a gig of pics and music. I also notice lag in loading and delteing photos through the phone

These are normal pics 5-6 MB. There has to be something wrong.

Irieone said:
These are normal pics 5-6 MB. There has to be something wrong.
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Click to collapse
If you find any info/solution let us know.
Im thinking about running it through one of the tests that show the read/write speed, if its not up to par on that I will contact samsung see if its covered under their warranty.

Why not opt for a 128GB sd card? My Moto X Pure will be here Thursday. I have a 64GB in my old phone but I may get 128.

Has the OP tried backing up their data and reformatting the card?

gpz1100 said:
Has the OP tried backing up their data and reformatting the card?
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Click to collapse
Yes, I have tried this a few times and it did not help. The write speed of this particular card is somewhere between 5 and 9 mb/sec. I have used multiple benchmarking tools that all confirm the same thing. The sad thing, if you drill down into the specifications for a lot of these new sd cards there is no mention of write- speeds. I asked a question similar to my OP on Reddit and had somebody with the same card echo my issue. Terrible write speeds. I am not in the mood to buy another card with great specs only to find it performs poorly in my phone? There is still a part of me that thinks it's hardware or software related and specific to the phone. I can't quite believe that something advertised as "turbo", UHS-1, Class 10, and 90 mb/sec has an actual write speed of 5 mb/sec. It seems criminal.

^^See my post #3. I've found this card to have very good write speeds on the phone of ~14-16 MB/s, reads around 40-50. On the pc through a usb 3 card reader I can write at the speeds posted above.
But yes, unless you drill down, the marketing and advertising doesn't list write speeds. I can see why. It all depends where you'll be using it. I'll be lucky to see sustained 10MB/s read through my dash cam (not sure what the write speed even is) even through the card is capable of 40MB/s +.
I should say, using the moto x, through MTP, I've seen read speeds upwards of 35-40MB/s, write speeds of about 7-10MB. The card is faster through twrp, backup stats indicate ~14-16MB/s.

http://forum.xda-developers.com/moto-x-style/general/micro-sd-speed-chart-t3196020

Related

Has anyone tried a Class 6/10 MicroSDHC card?

Found some Transcend and A-Data class 6 MicroSDHC cards that are sold cheaply on Amazon, but I'm not sure I want to spend the extra cash if the Evo has bottlenecked write/read speeds. So I was wandering if any of you have tested out a class 6 or 10 MicroSDHC card on the Evo.
The Evo comes with a Class 2 card.
Download "SD Card Speed Tester" from android market to base our results. Will be posting mine in a bit.
First test results for 8GB Class 2 MicroSDHC Card(Comes with Evo):
Write speed is 2.0MB/s
Read speed is 9.0MB/s
Second test same card:
Write 4MB/s
Read 9MB/s
Well I read that this test is inaccurate. I will try to find better, external methods.
Does the Geebees matter when it comes write/read speeds on SDHC cards?
I bought a 32GB class 6 from ebay. took a few weeks to get since it came from hong kong and i paid 40 bucks :] anyways, writing to the sd seems smoother to me. i havent "truly" tested since im a complete n00b
ripalsanghani said:
I bought a 32GB class 6 from ebay. took a few weeks to get since it came from hong kong and i paid 40 bucks
Click to expand...
Click to collapse
Since there are no 32 gb class 6 cards... you got taken.
I bought a 16 g class 6 in amazon. How do i test it? I mean to me writes and reads fast but is there a appl for that?
mikevillarroel said:
I bought a 16 g class 6 in amazon. How do i test it? I mean to me writes and reads fast but is there a appl for that?
Click to expand...
Click to collapse
Download "SD card speed tester" from android market.
without any "real" tests in android there really doesn't seem much of an improvement. mainly b/c the small amount of data that apps use.
nandroid back ups are faster though and prepping sd card at boot up is faster.
no numbers though.
madsquabbles said:
without any "real" tests in android there really doesn't seem much of an improvement. mainly b/c the small amount of data that apps use.
nandroid back ups are faster though and prepping sd card at boot up is faster.
no numbers though.
Click to expand...
Click to collapse
What about 720p recording.
Plancy said:
What about 720p recording.
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shoot, didn't think of testing that.
if no one else does it i'll do it later today if i can.
i went to a 16 gig class 2 card since space was more important than speed for me.
madsquabbles said:
shoot, didn't think of testing that.
if no one else does it i'll do it later today if i can.
i went to a 16 gig class 2 card since space was more important than speed for me.
Click to expand...
Click to collapse
Oh please do, can't test it, don't have a class 6 card. Hope some people who do stumble onto this thread.
I bought a 16GB Class 6 mSDHC card and I can tell you that it is noticeably better than the shipped 8GB Class2 card. I notice it most when playing back high bitrate vid, I ripped some stuff from blu-ray to 800x480 mpeg4 and it loads the video faster now and plays without a single hiccup. Also from time to time I would get hiccups in the 720p videos recording with the class2 and I have not had a single hiccup with my class 6 card.
These are just my observations I have no actual measurements to compare so take this with a grain of salt.
djmend said:
I bought a 16GB Class 6 mSDHC card and I can tell you that it is noticeably better than the shipped 8GB Class2 card. I notice it most when playing back high bitrate vid, I ripped some stuff from blu-ray to 800x480 mpeg4 and it loads the video faster now and plays without a single hiccup. Also from time to time I would get hiccups in the 720p videos recording with the class2 and I have not had a single hiccup with my class 6 card.
These are just my observations I have no actual measurements to compare so take this with a grain of salt.
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Click to collapse
, what brand/where did you get your Card?
posguy99 said:
Since there are no 32 gb class 6 cards... you got taken.
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Sorry, confused myself with the standard SD.
I just ran that SD speed card test, transcend c6 card. Not using a2sd or anything else. It reports write speed at 5MB/s, read at 10MB/s. Says its a c4 card. Dont know how accurate the test is but thought itd be useful posting...
*edit* ran it a second time and got write at 5, read at 11. Seems pretty consistant
TrevE said:
I just ran that SD speed card test, transcend c6 card. Not using a2sd or anything else. It reports write speed at 5MB/s, read at 10MB/s. Says its a c4 card. Dont know how accurate the test is but thought itd be useful posting...
*edit* ran it a second time and got write at 5, read at 11. Seems pretty consistant
Click to expand...
Click to collapse
Test multiple times, for some reason I got 4MB/s write the second time.
ran test a 3rd/4th time.
Write 6MB/s
Read 10MB/s
Write 5MB/s
Read 11MB/s
A fluctuation of a meg up or down i think is normal. The program might also round seeing i saw no partial numbers. Now as far as if its worth it to get a c6 id say yes regardless just for the wearleveling features.
from cyaogen wiki: http://wiki.cyanogenmod.com/index.php/Swap_and_Compcache
However, newer, high-end SD cards feature wear leveling, a mechanism that distributes write wear uniformly over the entire memory card by dynamically remapping logical memory blocks to different physical memory blocks over time. This largely alleviates the issue of card wear when using applications that tend to write to the same memory blocks over and over (i.e. swap). Most Class 6 microSDHC cards include hardware wear leveling, while Class 4 and lower cards typically do not. This feature depends on the decision of your card's manufacturer. A-Data and Transcend Class 6 cards were specifically cited as having hardware wear leveling.
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Click to collapse
I have a 16GBA a-data class 6 in mine and the speed test is showing 8mb write and 12mb read. Not sure how accurate that is though, the read speed is about 4mb faster than what my computer told me it was.
A-data cards are fast but if you get another brand make sure other people are saying they can do what they say they can. There are a lot of companies who flat out lie.
Plancy said:
Download "SD card speed tester" from android market.
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Click to collapse
Don't know if it's good or not but at least says is a class6
I seem to have gotten lucky with my Class 2 16GB.
Ran SD Card Speed Test from the market 3 times, and all 3 tests came back with at least 6MB/s write speed. Got it for $25 shipped off of Ebay. PM me if you want the seller, maybe someone else can get lucky too...
ripalsanghani said:
I bought a 32GB class 6 from ebay. took a few weeks to get since it came from hong kong and i paid 40 bucks :] anyways, writing to the sd seems smoother to me. i havent "truly" tested since im a complete n00b
Click to expand...
Click to collapse
Make sure you test it thoroughly before you run out of time to file a claim. There have been a lot of 16gb cards with the 32gb markings coming from china. It's formatted so it looks like the space is there but they wont let you use more than 16gig
Actually alot of the cards on ebay at 2gb cards. Not even a full 8 or 16. Also if you want to do a better test for your sd card speads use ATTO. its free and gives alot better breakdown. It runs on your PC.

Don't bother with anything above class 2 microSD cards

I bought a class 6 card and popped in the N1 and started copying files via USB... except it peaked out at 2mb! wtf, thought I, have I been screwed?
Pop it in a SD adapter, plug it into laptop.... copies at 8.5mb/sec
It would appear that the Nexus One itself limits the speed of sdcard writes. There is no point putting anything other than class 2 into the N1.
What a let down
Well the point is internal write speed, not external. Example would be taking a 720p video where you need fast write speed.
evilkorn said:
Well the point is internal write speed, not external. Example would be taking a 720p video where you need fast write speed.
Click to expand...
Click to collapse
+1
Also the problem of slow write speeds has also already been discussed in multiple threads. Pop my sd card into my old touch pro 2 and it copies files 5 times quicker than my nexus

Sd Card Class 10

Does anyone know the specific read and write megabytes per second limitations of our cpu's? More specifically i am wondering if we would benefit from a class 10 or if anything beyond a class 6 or are we wasting our money cuz the phone's cpu cant match the read and write speeds of a class 10. Also does anyone know how accurate sd card speed tester app is? I used it and it said with the stock class 2 sd card that it was reading 13mb per sec and writing 7mb per sec. If that is accurate then to my knowledge We would benefit from atleast a class 6 or higher.
I've looked for specs on this as well, but can't find anything, just that the max size supported is 32gb microsdhc. ;\ Would you really want to spend the money on a Class 10 card, though? $90 bucks for 16gb? No danke.
jbadboy2007 said:
Does anyone know the specific read and write megabytes per second limitations of our cpu's? More specifically i am wondering if we would benefit from a class 10 or if anything beyond a class 6 or are we wasting our money cuz the phone's cpu cant match the read and write speeds of a class 10. Also does anyone know how accurate sd card speed tester app is? I used it and it said with the stock class 2 sd card that it was reading 13mb per sec and writing 7mb per sec. If that is accurate then to my knowledge We would benefit from atleast a class 6 or higher.
Click to expand...
Click to collapse
The CPU itself would not be the limiting factor.
One tip: Sandisk's most expensive Class 10 flash is NOT the fastest for random-access reads. I've seen benchmarks done in multiple places that show that other brands (mostly sold by Newegg, nothing you can even fantasize about buying in a major retail store) are up to 50% faster.
The paradox is because "class" measures ONLY write speeds, but the way most guys here use it is as a fake hard drive in ways that are more read-intensive. Sandisk's target market isn't performance-oriented owners of high-end Android phones. Their target market is video professionals who only care about reliability and storage-life. As a result, if they have to choose between optimizing for long-term data integrity and raw blazing performance, they'll go for integrity every time as long as write performance is fast enough to meet the standard.
If you're going to walk into a store like CompUSA/TigerDirect and buy flash without reading reviews, your best bet is probably class 6. It's dirt cheap compared to class 10, and isn't much slower than average-benchmarking class 10 when it comes to reads. More to the point, it's cheap enough that if you strike out, you can chuck it and buy a more carefully-researched second card online without hating yourself for the next year. If you spend $15-20 on a mediocre class 6 4-gig card, it's not a big deal. If you spend $120+ on a mediocre class-10 16-gig card, you're basically stuck with it for the next 2 years unless you can unload it on somebody who doesn't know better.
write speeds are the more intensive and slower than read speeds. Kingston sells their products based upon write speeds. sandisk sells upon read speeds. kingston class 10 sd card equals 10 mb write speeds 19 mb read speeds sanddisk class 10 is 10 mb read and 7-8mb write speeds. it takes longer to write data and takes more cpu use. the write speeds are your priority.
Class 10
I have a class 10 Sandisk and it sucks in the nexus one
for some reason if I use the card in a reader it perform ok (10MB WRITE) but in the phone it is painfully slow... and this is true either testing with an SD card test app or by hooking thru the usb cable, so something is wrong and I am not sure it's 100% the card since it perform ok in a card reader...
Doing the same with a class 2 card is transparent, same performance from any interface (USB, Internal).
I have made some test with cluster size if 4K, 16K, 32K and it's the same... The only difference is the card themself, I know they use a new SDHC 3.0 standard, maybe this is the reson why they under perform in the nexus...
jbadboy2007 said:
write speeds are the more intensive and slower than read speeds. Kingston sells their products based upon write speeds. sandisk sells upon read speeds. kingston class 10 sd card equals 10 mb write speeds 19 mb read speeds sanddisk class 10 is 10 mb read and 7-8mb write speeds. it takes longer to write data and takes more cpu use. the write speeds are your priority.
Click to expand...
Click to collapse
You are right in regard to write being more intensive than read, especially for MLC flash but AFAIK Class are part of the SD Card standard and are based on WRITE Speed, can you point out where you take this "difference" between 2 major brand, I am not a sandisk fanboy (far from it) but I doubt this is based on anything real...
actually i read in wikipedia that sandisk sells thier products by read speed and kingston sells thier products by write speed.
It's been awhile since I looked at the spec, but the class is the minimum write speed to earn that spec. Most cards seem to exceed this. The only real way to find out real speeds is via independent tests.
Sent from my SPH-D700 using Tapatalk
Are the only 32 gb cards available Class 2? I haven't found anything faster.....

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...

Native SD (Where is the speed that everyone talking about?)

i have bought a new Sandisk Ultra 16GB class 10 card and flash nexushd2 rom in native sd but i notice no different than nand in the speed !!!
i test the card with h2testw_1.4 and it was ok the speed was 10mb R/W,
So Where is the Speed that everyone talk about !!!!
x_max_best said:
i have bought a new Sandisk Ultra 16GB class 10 card and flash nexushd2 rom in native sd but i notice no different than nand in the speed !!!
i test the card with h2testw_1.4 and it was ok the speed was 10mb R/W,
So Where is the Speed that everyone talk about !!!!
Click to expand...
Click to collapse
That's basically because it's a myth .
I'm kidding, I don't know if it is or not, but personally, I didn't notice any speed difference or improvement. I tried different ROMs, they all behaved as if they were on NAND. I have the same card as you do.
Someone told me once: "It's because you have a UHS card, HD2 doesn't support them so the speed is degraded".
I am not sure of that, but there was no apparent improvement over NAND installation.
+1, I never saw any speed difference. My guess is that since it would theoretically be faster there was a placebo effect and people actually felt their phones being faster. The same thing happens with build.prop tweaks and the entropy seed generator, both of which had great comments but no actual effect on my phone.
x_max_best said:
i have bought a new Sandisk Ultra 16GB class 10 card and flash nexushd2 rom in native sd but i notice no different than nand in the speed !!!
i test the card with h2testw_1.4 and it was ok the speed was 10mb R/W,
So Where is the Speed that everyone talk about !!!!
Click to expand...
Click to collapse
You should read first my friend,this way you will save some Money,any Sandisk class 4 will be faster than any class 10 in native sd, simply because with a class 10 card you get high sequential data transfer and very low random data transfer, and that is the secret random access transfer rate.
But the manufacturers won't tell you the random access speeds, you have to test.
Use crystal disk mark to test the sd and check for the last 2 values..
And read..and search..
Sent from my GT-I9300 using xda premium
x_max_best said:
i have bought a new Sandisk Ultra 16GB class 10 card and flash nexushd2 rom in native sd but i notice no different than nand in the speed !!!
i test the card with h2testw_1.4 and it was ok the speed was 10mb R/W,
So Where is the Speed that everyone talk about !!!!
Click to expand...
Click to collapse
I can confirm that the problem is with the Sandisk Ultra SD Card. I had good read but very poor write speeds on a Sandisk UHC which caused all sorts of problems. I changed to a Samsung Class 10 32Gb card and the difference is very noticeable The Sandisk gave a write speed of about 3/4 Mbs and a read speed of about 15 Mbs. The Samsung now gives a write speed of 9.7 and a read speed of 20.15. Both tested with a cache size of 2048Kb.
sandymac said:
I can confirm that the problem is with the Sandisk Ultra SD Card. I had good read but very poor write speeds on a Sandisk UHC which caused all sorts of problems. I changed to a Samsung Class 10 32Gb card and the difference is very noticeable The Sandisk gave a write speed of about 3/4 Mbs and a read speed of about 15 Mbs. The Samsung now gives a write speed of 9.7 and a read speed of 20.15. Both tested with a cache size of 2048Kb.
Click to expand...
Click to collapse
I had the same low write speed in native SD (3 mb), but i flash the rom again in DataonExt mod and the speed of write was 7 mb and i feel some speed up in apps (not in the rom) Rom toolbox collect data faster , I think there is something wroung with Native SD ,the speed of write should be higher than 3mb
Edit: it was a placebo effect , there is no speed up in DataonExt , i test the same app in Nand
x_max_best said:
I had the same low write speed in native SD (3 mb), but i flash the rom again in DataonExt mod and the speed of write was 7 mb and i feel some speed up in apps (not in the rom) Rom toolbox collect data faster , I think there is something wroung with Native SD ,the speed of write should be higher than 3mb
Click to expand...
Click to collapse
Well, if you looked, I am on Native SD and generally manage around the 10Mbs write with 20Mbs read so nothing wrong with Native SD.
as the creators of nativeSD and others have pointed out, it's all down to the small block size random read/write speed, that's what most read/writes are when running an OS, small and random.
While reading (for example) a video, it will read bigger, almost certainly sequential, block sizes.
The industry quoted max speed of a card is almost always based on the largest block size, usually read, always sequential speed, so a class 10 can read large block sizes at 10meg, however, test the card for all different block sizes and you'll see that small random r/w's are wayyyyy slower, massively so, often on the order of a factor of 1000 slower.
In general, the lower class cards actually beat the class 10s, often by a large factor, so the rom running from it feels snappier and more responsive than on a class 10.
Check out the (admittedly over a year old, but still a good example) comparison charts HERE, and note especially the 4th and 5th charts, where the class 4 blows the others down by over a factor of 100
http://www.tomshardware.com/reviews/microsdhc-memory-card-performance,3011-12.html
samsamuel said:
as the creators of nativeSD and others have pointed out, it's all down to the small block size random read/write speed, that's what most read/writes are when running an OS, small and random.
While reading (for example) a video, it will read bigger, almost certainly sequential, block sizes.
The industry quoted max speed of a card is almost always based on the largest block size, usually read, always sequential speed, so a class 10 can read large block sizes at 10meg, however, test the card for all different block sizes and you'll see that small random r/w's are wayyyyy slower, massively so, often on the order of a factor of 1000 slower.
In general, the lower class cards actually beat the class 10s, often by a large factor, so the rom running from it feels snappier and more responsive than on a class 10.
Check out the (admittedly over a year old, but still a good example) comparison charts HERE, and note especially the 4th and 5th charts, where the class 4 blows the others down by over a factor of 100
http://www.tomshardware.com/reviews/microsdhc-memory-card-performance,3011-12.html
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yugoport said:
You should read first my friend,this way you will save some Money,any Sandisk class 4 will be faster than any class 10 in native sd, simply because with a class 10 card you get high sequential data transfer and very low random data transfer, and that is the secret random access transfer rate.
But the manufacturers won't tell you the random access speeds, you have to test.
Use crystal disk mark to test the sd and check for the last 2 values..
And read..and search..
Sent from my GT-I9300 using xda premium
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This is crystal disk mark for my SD Card , See it and tell me where exactly the problem !!
x_max_best said:
This is crystal disk mark for my SD Card , See it and tell me where exactly the problem !!
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Click to collapse
Look at my scandisk class 2 32 gb below, in the last field at right is basically more than 30 times faster than yours in the random write..
https://www.dropbox.com/s/bgbm6tcv99a1r7j/scandisk class 2 32 gb.JPG
This is crystal disk mark for my SD Card , See it and tell me where exactly the problem !!
Click to expand...
Click to collapse
The random write speed is to low! Look by "write 4k" and "write 4k/QD32".
Look here, the second ranking is importand for us:
http://forums.whirlpool.net.au/forum-replies.cfm?t=1582172
And here from XDA:
http://forum.xda-developers.com/showthread.php?t=1150369
x_max_best said:
This is crystal disk mark for my SD Card , See it and tell me where exactly the problem !!
Click to expand...
Click to collapse
as already noted 4k and 4kqd32 (qd32 = there are 32 or more write operations in the queue, probably quite common when running an operating system) speeds are atrocious, thats gonna be your real speed, more often than not, somewhere between 38K/sec and 0.6MB/sec,,, a world away from 10MB/sec. Course, oftentimes the system is reading those small blocks, not writing, which is faster so you can probably make a rough estimate of total average r/w at around 2MB/sec, still a long way from 10MB/sec
yugoport said:
Look at my scandisk class 2 32 gb below, in the last field at right is basically more than 30 times faster than yours in the random write..
https://www.dropbox.com/s/bgbm6tcv99a1r7j/scandisk class 2 32 gb.JPG
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Click to collapse
Fietz said:
The random write speed is to low! Look by "write 4k" and "write 4k/QD32".
Look here, the second ranking is importand for us:
http://forums.whirlpool.net.au/forum-replies.cfm?t=1582172
And here from XDA:
http://forum.xda-developers.com/showthread.php?t=1150369
Click to expand...
Click to collapse
Your Conclusion is wroung , i retest my card with CrystalDiskMark and the result was interesting (attachment) ,and all i did to get this result is change the test size to 50 mb , i start to believe that there is noting called fast Native SD , it is just placebo effect.
if you want me to believe u ,provide a video in Youtube for the fast Native SD that u have and let me know what do u mean by fast Native SD
x_max_best said:
Your Conclusion is wroung , i retest my card with CrystalDiskMark and the result was interesting (attachment) ,and all i did to get this result is change the test size to 50 mb , i start to believe that there is noting called fast Native SD , it is just placebo effect.
if you want me to believe u ,provide a video in Youtube for the fast Native SD that u have and let me know what do u mean by fast Native SD
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I don't need to prove anything..if you think it's not fast or it doesn't suits you use nand.. I have more important things to do..
Sent from my GT-I9300 using xda premium

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