OESF Portables Forum
Model Specific Forums => Sharp Zaurus => Zaurus - pdaXrom => Topic started by: sigmaX on August 24, 2004, 11:07:59 am
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Is there any existing application that measures speed in a storage medium, compiled for PdaXrom ? If not.... any cool soul can do it ?
Maybe it can be done from scratch:
1) start a timer
2) Store a dummy file (size user configurable)
3) measure save speed
4) Read that file
5) measure read speed
I bought an SD card that suppossedly is "Speeded up" (A viking 512MB) but I think it is no good speed behind it ... I would love to see actual numbers !!
Regards,
Enrique.
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Maybe it's a little n00b solution and not accurate, but this is how I imagine a simple test:
Writing speed test (writing a 32Mb file to SD card):
# time dd if=/dev/zero of=/mnt/card/testfile count=65536You get a real time, Divide it by 32 get the reciproc (1/x) and tadaaa. You get a Mb/sec value from it.
The read test is just the same:
# time dd if=/mnt/card/testfile of=/dev/nullSame procedure.
Ohh, and a tip: don't forget to delete the testfile.
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1,301 Mb/sec reading and 1,217 Mb/sec writing speed here. Yeah, it was the cheapest SD in the store.
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I'm not sure how to read these results, but I got 38.746s for the first test, and 5.888s for the second test. What does that mean?
By the way, I'm using a 256MB SimpleTech SD card.
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I'm not sure how to read these results, but I got 38.746s for the first test, and 5.888s for the second test. What does that mean?
By the way, I'm using a 256MB SimpleTech SD card.
Divide it by 32 (38.746/32=1.211) and get the reciproc (1/1.211=0.826). So you have a 0.826 Mb/sec card writing speed. The reading is much better, but... calculate it yourself.
Zumi
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There is already a good program available for doing read and write speed tests. See this thread (https://www.oesf.org/forums/index.php?showtopic=5380&hl=bonnie) for instructions and the download link.
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Damned Viking card, bought thru amazon .... they stated "6 mb per second transfer speed" ... blah blah ... it goes like:
0m41.652s for writing
0m24.345s for reading
It's formatted in ext2 .. and got some stuff already in it ... I think that being with some megs already in use deteriorates the test result ... but anyway it is pretty slow !!
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zumi I have not clear at all your math ... you create a file with count=65536 and state it is a 32 mb file ?
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Hi
I guess that the count argument to dd is not in bytes but in blocks. Each block is 512 bytes, that gives the 32MB file size. (Please correct me if I'm wrong)
Anyhow, have you guys had any problems with corruption while doing your tests? I have had some major SD corruption since I bought my Sandisk card. The only thing that helps is to include the sync parameter when mounting.
/Marcus
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Hi
I guess that the count argument to dd is not in bytes but in blocks. Each block is 512 bytes, that gives the 32MB file size. (Please correct me if I'm wrong)
Anyhow, have you guys had any problems with corruption while doing your tests? I have had some major SD corruption since I bought my Sandisk card. The only thing that helps is to include the sync parameter when mounting.
/Marcus
Correct, tt creates a 32Mb file.
Sync is your friend anyway. It forces the system to write everything immediately to the card. This is good, because you can pull out the cards anytime; maybe by accidentally, or you forgot that you just wrote something on it and it is not physically written on it yet. And you create a mess on your card with this move. So use sync! (isn't this the default anyway??? because if not, this test would be highly imprecise)
Zumi
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Its quite interesting about the SYNC parameter. It took me about 5 min to thrash the SD card after installing 1.1.0-RC2 since the SYNC parameter wasn't set in the fstab file. I added it and reformatted the card and no problems so far.
I cant remember exactly but I think that my performace for both write and read was about 23 sec, no too bad anyhow.
/Marcus
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I've just got a Kingmax 512MB MMC (not SD) formatted with FAT16.
Using Zumi's method I get:
Read: 1.5MB/s
Write: 1.5MB/s
Pretty impressed by that for a MMC card.
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Just ran this test on my brand new Lexar 1GB SD:
Write - 1.86MB/s
Read - 32.52MB/s
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Lexar SD128 (ext2):
Write: 0.55 Mbit/sec
Read: 1.3 Mbit/sec
Bytestor "Hi-speed" CF 256M (FAT):
Write: 1.3 Mbit/sec
Read: 2.1 Mbit/secMbit/sec
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lexar 256 MB 32x high-speed (ext2)
write 1.33 Mb/
read 42.78 Mb/s
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SanDisk ultra ll CF (fat 16)
write: 2.82 Mb/s
read: 42.66 Mb/s