Re: For the Wiki: Memory cards: Is Speed Important?
 

Where is that page?
That information is wrong. Even unpatched kernel should be able to write at 6-7MB/s. In 48Mhz mode when CPU is not slowed down by powersaving code (there is a bug reported about this) it can do ~11MB/s while reading and only slightly less when writing.

Re: For the Wiki: Memory cards: Is Speed Important?
 

I'll echo this, which wiki? (hint: 'the itT wiki' is the wrong answer ;))

Re: For the Wiki: Memory cards: Is Speed Important?
 

It all depends what you're doing while writing; perhaps whoever came up with that was downloading the file, or copying from some limited-speed device. :) Reliable benchmarking's not as easy as some people think...

Re: For the Wiki: Memory cards: Is Speed Important?
 

This page:
http://www.internettablettalk.com/wi...peed_Important

Something make me suppose this thread was a discussion about it :-)

Thank you very much for the clarification.
I hope some well informed people will review that page.

Re: For the Wiki: Memory cards: Is Speed Important?
 

I'm sorry, I haven't a better answer than the wrong one :rolleyes:

Do you have any suggestions? :D

Re: For the Wiki: Memory cards: Is Speed Important?
 

Just to clarify a bit more - those speeds are raw block device speeds. Filesystem brings overhead so real numbers when creating/copying files may be slower (significantly in some cases).


Here are tests I just made on N800 running OS2007 with Transcend 150x 4GB SD card.

Nokia-N800-26:~# sync ; time sh -c 'dd if=/dev/zero of=/media/mmc1/testfile bs=102400 count=1024; sync'
1024+0 records in
1024+0 records out
real 0m 19.60s
user 0m 0.00s
sys 0m 1.45s
Nokia-N800-26:~# ls -l /media/mmc1/testfile
-rwxr-xr-x 1 user root 104857600 Aug 4 22:31 /media/mmc1/testfile
Nokia-N800-26:~# sync ; time sh -c 'dd if=/dev/zero of=/media/mmc1/testfile2 bs=1024 count=102400; sync'
102400+0 records in
102400+0 records out
real 0m 31.80s
user 0m 0.20s
sys 0m 3.64s
Nokia-N800-26:~# sync ; time sh -c 'dd if=/dev/zero of=/media/mmc1/testfile2 bs=102400 count=1024; sync'
1024+0 records in
1024+0 records out
real 0m 19.38s
user 0m 0.00s
sys 0m 1.63s
Nokia-N800-26:~# sync ; time sh -c 'dd if=/dev/zero of=/media/mmc1/testfile2 bs=4096 count=25600; sync'
25600+0 records in
25600+0 records out
real 0m 19.65s
user 0m 0.01s
sys 0m 2.05s

all tests created 100MB file on FAT partition. With block size 1024 bytes speed is ~3MB/s, with block size 4096 and up speed is ~5MB/s. This includes filesystem overhead.

Here is raw block device writing speed (zeroing 100MB beginning of first partition)

Nokia-N800-26:~# sync ; time sh -c 'dd of=/dev/mmcblk1p1 if=/dev/zero bs=102400 count=1024 ; sync'
1024+0 records in
1024+0 records out
real 0m 10.23s
user 0m 0.01s
sys 0m 1.28s

100MB in 10 seconds

and finally restoring data to mmcblk1p1 partition from file on mmcblk0p4 formatted as ext2
Nokia-N800-26:~# sync ; time sh -c 'dd of=/dev/mmcblk1p1 if=/SD4GB bs=102400 count=1024 ; sync'
1024+0 records in
1024+0 records out
real 0m 18.80s
user 0m 0.03s
sys 0m 2.56s

5MB/s raw write speed while reading real data from other mmc card

Re: For the Wiki: Memory cards: Is Speed Important?
 

By the way, fans of SEARCHING could have answered the question "which Wiki is that" by putting the following string (and indoubtedly others) into Google.

"the tablet itself is not be capable of writing"

The quotes of course make Google come up with that exact phaseology. Google comes up with only one result, so looking thru the results is not difficult.

Re: For the Wiki: Memory cards: Is Speed Important?
 

http://wiki.maemo.org

:rolleyes: The King of Useless Sarcasm strikes again.