Flash writing and reading speed (was: Re: Picture viewer?)
Mike Montour
mail at mmontour.net
Fri Feb 15 07:59:51 CET 2008
Asheesh Laroia wrote:
> Not to mention eight megabytes of I/O from the micro-SD slot. I don't
> have my Neo on-hand, but it'd be great to see some performance numbers
> that can indicate what sort of performance is reasonable to expect.
I have written a small program that measures the speed of writing and
reading a file. It is located at
http://members.shaw.ca/mmontour/neo/iospeed (with a .c source file in
the same directory) and it takes 2 parameters - the filename, and the
desired size in MiB. Examples for my GTA01:
NAND flash, jffs2 filesystem:
root at fic-gta01:/mnt# ~/iospeed test.dat 8
Size (MiB) Write (MiB/s) Read (MiB/s)
8 1.503 7.113
Kingston 2G SD-card, ext3 filesystem:
root at fic-gta01:~# ~/iospeed test.dat 8
Size (MiB) Write (MiB/s) Read (MiB/s)
8 2.276 3.243
The write measurement includes the time to fsync() the file after
writing all of the data, and the cache is flushed with posix_fadvise()
before performing the read test.
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