SanDisk micro SDHC 8GB card under testing

Mike Montour mail at
Sat Jul 12 05:58:41 CEST 2008

ian douglas wrote:
> ian douglas wrote:

> Mike, your binary is 420kb ... I'm guessing that you compiled your code
> with the cross-compiler toolchain?

Probably, but it was a while ago and I don't remember where I built it 
(I have a MokoMakefile cross-compile environment and a native toolchain 
on the Neo). Anyway, a natively-compiled version should be fine.

> I moved the iospeed files to /opt/ so I could compare against the 512MB
> card that shipped with the Freerunner, and ran Mike's utility three
> times on the 8GB SDHC card:
> root at om-gta02:/media/card# /opt/iospeed2 testfile 100
> Size (MiB)	Write (MiB/s)	Read (MiB/s)
> 100	1.557	9.396
> and once on the unit's own Flash ROM as a comparison:
> root at om-gta02:/media/card# cd /opt
> root at om-gta02:/var/volatile/opt# /opt/iospeed2 testfile 50
> Size (MiB)	Write (MiB/s)	Read (MiB/s)
> 50	1.577	9.530

Those numbers are very similar, and given the numbers that you posted in 
your later email I would guess that the 8G card was not actually mounted 
for this test run.

> Then tested /tmp which I guess is a RAM drive considering the speed boost:
> root at om-gta02:/media/card# cd /tmp
> root at om-gta02:/var/volatile/tmp# /opt/iospeed2 testfile 50
> Size (MiB)	Write (MiB/s)	Read (MiB/s)
> 50	28.617	42.786

Yes, /var/volatile is a 'tmpfs' filesystem.

More information about the community mailing list