SanDisk micro SDHC 8GB card under testing

[ian douglas]

Federico Lorenzi wrote:
> Makes sense, ext3 is journaled, and using a journaling FS on flash
> memory is generally a bad idea. Could you also try ext2?

Sorry, I'm not up to speed on flash and file systems -- why is a
journaled file system a bad idea?


I re-ran all of my tests on the new 8GB SanDisk micro SDHC card:


I built an 8GB partition, type 'b' (win95 fat32), formatted as 'vfat'
done on Ubuntu, then installed in my Freerunner and started up:

root at om-gta02:/media/card# /opt/iospeed2 testfile 100
Size (MiB)      Write (MiB/s)   Read (MiB/s)
100	2.038	2.755


Ran fdisk on the Freerunner, changed partition type to '83' (linux),
formatted as ext3, re-mounted as /media/card:

root at om-gta02:/media/card# /opt/iospeed2 testfile 100
Size (MiB)      Write (MiB/s)   Read (MiB/s)
100	2.046	2.643


Then re-formatted as ext2 and re-mounted as /media/card:

root at om-gta02:/media/card# /opt/iospeed2 testfile 100
Size (MiB)	Write (MiB/s)	Read (MiB/s)
100	2.107	2.779


Conclusions:
- very little difference writing a 100MB file.
- ext3 is slower, on average for reading, while vfat and ext2 are pretty
similar.


Should I try it again with smaller file sizes?

Should I try it again with the various partition/fs types running
bonnie++ to see how it benchmarks things too?