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SD writes faster than it reads?

Hi. I've benchmarked my class 2 SD card with several different benchmark programs (both android and pc) and they all return the same result: read - 1.5 mb/s and write - 5 mb/s. Is this normal?

You might be experiencing what is called write caching.
This would lead to display of higher speeds with small amounts of data.
Try copying a large file - 2GB or more, for instance - and you will see that it will stabilize around your actual write speed at some point. It might still be 5MB/s as the Class 2 of your SD card guarantees minimum speeds, not maximum

[POLL] Which microSD card works best for you?

With all of the vast information over numerous pages of peoples experiences with different cards, i thought i would make a poll which should give us a very good indication of the card most likely to work.
This is NOT an indication of a card that WILL work, as many of you know. This will provide you with a statistical outlook on which card is more likely to be a success.
So, please choose the card you have had the most successs with.
And please feel free to have a conversation in the thread about your experiences, we need this to remain at the top of the forum.
If a moderator could lock it at the top that would be great!
**I Hope i have added the most common ones, if yours isnt listed, please state it below.**

wow, no ones voted, thought this might be a good idea... but apparently not.
Fair enough, was worth a try.

give it a chance, thats the first i saw this, you must have posted it at a busy time of day and it shot off the screen
Probably worth printing in BIG BOLD LETTERS
that this doesnt give an indication of a card deffinitely working, thats my biggest gripe with the other thread, "Confirmed" my arse

Not to be a nag, but, could part numbers be listed for these cards? It makes it much easier to find the particular card that may work rather than just a 8gb class 2 sandisk, of which there may be 2 or 3 different part numbers.

Can anyone please tell me how to know class of the sd card?
and which one comes with hd2 originally?

The Class number it printed on the front with a circle around it.
I also have pretty conclusive evidence that the Crystal mark program is a bit useless at determining if a card will work.
First of all i was a bit skeptical because a card which worked, was apparently slower than a card that didnt work.
I have Benchmarked the results of the SAME CARD ( Sandisk 8GB Class 2) on two different readers.
1. (the card reader inside my computer, microsd inside a SD card adapter) Gives me;
Code:
-----------------------------------------------------------------------
CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
Crystal Dew World : http://crystalmark.info/
-----------------------------------------------------------------------
* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]
Sequential Read : 4.814 MB/s
Sequential Write : 5.657 MB/s
Random Read 512KB : 4.800 MB/s
Random Write 512KB : 1.551 MB/s
Random Read 4KB (QD=1) : 2.705 MB/s [ 660.5 IOPS]
Random Write 4KB (QD=1) : 1.488 MB/s [ 363.3 IOPS]
Random Read 4KB (QD=32) : 2.402 MB/s [ 586.5 IOPS]
Random Write 4KB (QD=32) : 0.780 MB/s [ 190.4 IOPS]
Test : 50 MB [F: 0.1% (5.0/7572.0 MB)] (x1)
Date : 2011/08/16 12:52:48
OS : Windows 7 Ultimate Edition SP1 [6.1 Build 7601] (x64)
2. And the USB card reader dongle that came with the card
Code:
-----------------------------------------------------------------------
CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
Crystal Dew World : http://crystalmark.info/
-----------------------------------------------------------------------
* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]
Sequential Read : 20.049 MB/s
Sequential Write : 6.554 MB/s
Random Read 512KB : 19.448 MB/s
Random Write 512KB : 1.228 MB/s
Random Read 4KB (QD=1) : 3.907 MB/s [ 954.0 IOPS]
Random Write 4KB (QD=1) : 0.471 MB/s [ 115.0 IOPS]
Random Read 4KB (QD=32) : 3.714 MB/s [ 906.8 IOPS]
Random Write 4KB (QD=32) : 0.276 MB/s [ 67.4 IOPS]
Test : 50 MB [F: 0.1% (5.0/7572.0 MB)] (x1)
Date : 2011/08/16 12:53:32
OS : Windows 7 Ultimate Edition SP1 [6.1 Build 7601] (x64)
As you can see the speeds vary by a huge amount. Havent had the chance to test this card out on my phone yet.
Just flashing a clean rom at the moment, before i insert a new card (which everyone should do!)

click
Can anyone give some feedback about this card?
Thanks!

actually, i know we were talking before about this, could you try the card attached to the phone its self
what your saying actually makes perfect sense, connecting a card to reader is essentially adding a different layer of hardware/protocols between the computer and the card, different "readers" may employ different tech which may in turn effect performance
I wonder what the results of your card would be attached to the phone itsself and connected to a hard USB port (not an external HUB) that way we would be using the same reader. All the cards ive tested for IOPS still appear to show that random reads / writes need to be +600 / +20 IOPS, lower than that and they become unstable

Mass13 said:
click
Can anyone give some feedback about this card?
Thanks!
Click to expand...
Click to collapse
What feedback do you want on it? It may or it maynot work, i would be carefull before forking out that much money! Go for a smaller card, then if it doesnt work, you can buy another one... my advice anyway

dazza9075 said:
actually, i know we were talking before about this, could you try the card attached to the phone its self
what your saying actually makes perfect sense, connecting a card to reader is essentially adding a different layer of hardware/protocols between the computer and the card, different "readers" may employ different tech which may in turn effect performance
I wonder what the results of your card would be attached to the phone itsself and connected to a hard USB port (not an external HUB) that way we would be using the same reader. All the cards ive tested for IOPS still appear to show that random reads / writes need to be +600 / +20 IOPS, lower than that and they become unstable
Click to expand...
Click to collapse
Yea i was thinking the same. Ive just tried doing exactly that (there is only 200mb viewable) and it gives me a write error.

stevemilw said:
Yea i was thinking the same. Ive just tried doing exactly that (there is only 200mb viewable) and it gives me a write error.
Click to expand...
Click to collapse
intresting, have you tried android to gain access to the card, dont know why it does that, works fine here, unless again there is some thing we are not seeing at a low level that effects cards.

Slow internal /sdcard write speeds ?

I just tested our TF101 with "sd card tester" and the write speeds are really slow - 2.24 MB/s for a 472MB test file while the read is pretty decent - 12.09 MB/s. Compared with my new Kingmax MicroSD Class 6 doing :
read speed - 9.89 MB/s average
write speed - 10.81 MB/s average
How's it possible that the write speed is so incredibly slow? Could anyone test it out with the "sd card tester" app from the Android Market and let me know?

i got 9.59 write speed and 11.54 read speed

damn...
the internal memory is so slow at writing..
i use a cache of 3072 with 300mb test file lenght
internal sd card:
write 2.68 mb/s
read 19.97 mb/s
class 6 external card
write 10.44 mb/s
read 18.66 mb/s

Internal
Write 8.18
Read 16.07
External 8Gb MicroSDHC class4
Write 43.77
Read 43.29
FullSD Panasonic HighSpeed
Write 31.7
Read043.78

FWIW my write to internal SD was ~5 mb/s initially. I freed up about 6 gigs space by deleting some video content and it improved to close to 9 mb/s.

Those with > 5mb write speed, are you guys on custom or stock rom?
also guys please try it on a larger test file like > 2gb if you have the space or as much as you can, the results would be more accurate. using a small test file i could get around 9mb too

[Q] Recommended SD transffers

Hi. If your WP7 installs and runs apps correctly, then could you please make a WPBench data test on 5MB and tell me your storage transfer please?
Mine is 3.5MB/s and it takes about 10 minutes to install 10MB app.

kubekpop said:
Hi. If your WP7 installs and runs apps correctly, then could you please make a WPBench data test on 5MB and tell me your storage transfer please?
Mine is 3.5MB/s and it takes about 10 minutes to install 10MB app.
Click to expand...
Click to collapse
your card is too slow... from my experience all below 5 MB/s is slow and make too much problems and "hiccups"
for my Sandisk 32GB Class 2 transfer rate is around 8 MB/s

Will SanDisk's 16GB class10 (already ordered) be better? And why this one is so slow?

Kingston microSDXC UHS-I U3 too slow as the internal memory?

I noticed little issue with my brand new Moto X Play (upgraded to Android 6.0). I bought sd card Kingston microSDXC 64 GB UHS-I U3 90 MB/s read and 80 MB/s write, put to device and formatted as internal memory. After successful formatting phone displays popup: "Card is too slow". I did benchmark (A1 SD Bench). Results: Read about 20 MB/s and Write about 15 MB/s. The strange thing is that I do not feel any lag when I launching app installed on sd card (it launches nearly in the same time as from phone internal storage). Has anyone had a similar problem?

Kubasagan07 said:
I noticed little issue with my brand new Moto X Play (upgraded to Android 6.0). I bought sd card Kingston microSDXC 64 GB UHS-I U3 90 MB/s read and 80 MB/s write, put to device and formatted as internal memory. After successful formatting phone displays popup: "Card is too slow". I did benchmark (A1 SD Bench). Results: Read about 20 MB/s and Write about 15 MB/s. The strange thing is that I do not feel any lag when I launching app installed on sd card (it launches nearly in the same time as from phone internal storage). Has anyone had a similar problem?
Click to expand...
Click to collapse
I experienced the same thing with my phone. After formatting my new strontium 64 gb uhs 1 card for internal show, it displayed the 'card too slow" message. After running the benchmark test, I got around 25mbps read and 14 mbps write speed.
Planning to return the card. How has your experience been so far using this card?