SD-Card slow with Filesystem FAT32

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Hello,

with FAT-Filesystem on 2Gb Card normal speed; with 8GB-Card and FAT32 is it 
very very slow.

Both cards MicroSD from Kingston.

Original issue reported on code.google.com by halloren...@googlemail.com on 11 Nov 2011 at 8:58

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My card is formatted with FAT32 and it is fast (Patriot 16GB Class10). Boots 
Android in about 2 minutes.

Original comment by sven.wit...@gmail.com on 11 Nov 2011 at 1:33

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May be. But really:

Cache size setted to 2048kb.

Here are the Read/write-Testresults:

Kingston 2GB card
Write --> 6,2MB/min
Read--> 30MB/min

Kingston 8GB card
Write --> 6,6MB/min
Read --> 22,1MB/min

Then formatted with SDformatter (fuöll overwrite) and changed "Allocation Unit 
Size" from 32k to 64k at the 8GBcard. After this we have:
Write --> 5,2MB/min
Read --> 26,9MB/min

Another issue is: the SD is very hot after a while!

Original comment by halloren...@googlemail.com on 11 Nov 2011 at 8:01

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system is running from SD-card, especially when you install/uninstall apps etc 
your card gots very stressed, so this "heat" problem is normal.

you can only use FAT32 format, recommended allcation unit size is 32k, 64k 
could be faster on cards with 8gb and higher but might be more unstable. your 
read values are very good, your write values are ok (if you min MB/sec, 
otherwise its very slow). dont forget: NAND r/w is about 2MB/sec.

after all its not a android issue ->

Original comment by b.baerth...@gmail.com on 20 Nov 2011 at 3:40

• Changed state: Done