SanDisk micro SDHC 8GB card under testing

[Francesco Cat]

this is extremely interesting! On the Wiki we should add the max (or
medium) read and write speed I think. This will grant no surprises at
all for anyone buying a listed card

2008/7/11 ian douglas <ian.douglas at iandouglas.com>:
> ian douglas wrote:
>> I'll try Mike's iospeed utility next, but here's a dual-run of the
>> bonnie++ utility:
>
> I should mention too that before running bonnie++ or Mike's utility,
> that I deleted the FAT32 partition on the 8GB card, created a single
> primary type-83 Linux partition and formatted it ext3. Since I rarely
> run Windows at home any more, I didn't see any need to continue to use
> vfat-formatted memory cards.
>
>
> Mike Montour wrote:
>> http://members.shaw.ca/mmontour/neo/iospeed is a simple
>> performance-test program that I wrote (source is "iospeed.c" in the
>> same directory)
>
> Mike, your binary is 420kb ... I'm guessing that you compiled your code
> with the cross-compiler toolchain?
>
> After installing gcc/g++ and stdlib stuff via opkg on the Freerunner, I
> was able to compile the utility directly on the Freerunner and it came
> out to only 15kb.
>
> Either way, here's my results with the 8GB SDHC card:
>
> root at om-gta02:/media/card# wget \
> http://members.shaw.ca/mmontour/neo/iospeed
>
> root at om-gta02:/media/card# chmod +x iospeed
>
> root at om-gta02:/media/card# wget \
> http://members.shaw.ca/mmontour/neo/iospeed.c
>
> root at om-gta02:/media/card# gcc iospeed.c -o iospeed2
>
> root at om-gta02:/media/card# ls -l
> -rwxr-xr-x    1 root     root       418384 Jul 10 21:08 iospeed
> -rw-r--r--    1 root     root         2444 Jul 10 21:08 iospeed.c
> -rwxr-xr-x    1 root     root        14758 Jul 10 21:19 iospeed2
>
> root at om-gta02:/media/card# ./iospeed2
> usage: ./iospeed2 <filename> <size-in-MiB>
>
> 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     0.776   8.890
>
> root at om-gta02:/media/card# /opt/iospeed2 testfile 100
> Size (MiB)      Write (MiB/s)   Read (MiB/s)
> 100     1.566   9.417
>
> 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
>
> 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
>
>
> The 512MB card that came with my Freerunner has some other files on it,
> and is formatted as vfat/FAT32. I ran the iospeed utility there three
> times as well:
>
> root at om-gta02:/media/card# /opt/iospeed2 testfile 100
> Size (MiB)      Write (MiB/s)   Read (MiB/s)
> 100     2.020   2.739
>
> root at om-gta02:/media/card# /opt/iospeed2 testfile 100
> Size (MiB)      Write (MiB/s)   Read (MiB/s)
> 100     2.187   2.743
>
> root at om-gta02:/media/card# /opt/iospeed2 testfile 100
> Size (MiB)      Write (MiB/s)   Read (MiB/s)
> 100     2.207   2.736
>
>
> So according to Mike's utility, writing the the 8GB card is slightly
> faster, but reading is several times slower reading the 512MB card.
>
> I was curious if this was a vfat vs ext3 performance hit, so I deleted
> the partition on the 512MB card, built a primary type 83 partition,
> formatted it ext3 and re-ran the iospeed tests:
>
> root at om-gta02:/media/card# /opt/iospeed2 testfile 100
> Size (MiB)      Write (MiB/s)   Read (MiB/s)
> 100     1.789   2.495
>
> root at om-gta02:/media/card# /opt/iospeed2 testfile 100
> Size (MiB)      Write (MiB/s)   Read (MiB/s)
> 100     1.722   2.505
>
> root at om-gta02:/media/card# /opt/iospeed2 testfile 100
> Size (MiB)      Write (MiB/s)   Read (MiB/s)
> 100     1.786   2.478
>
> So interestingly enough, writes were slower on ext3 than vfat on the
> 512MB card.
>
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