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Posts: 64 | Thanked: 9 times | Joined on Jun 2007 @ abuja, nigeria (currently)
#1
I've compiled hdparm ( http://sourceforge.net/projects/hdparm/ ) v 7.5 as found on my gentoo distribution for the n800 latest firmware and placed it on http://www.janerob.com/rob/n800/ . it's not a .deb, it is a binary arm executable -- just download and run in an xterm (and I guess you just have to trust me that its not going to turn your n800 into a spam shipping ddos daemon, or re-compile yourself if you like).

I have 2 sdhc cards purchased from www.7dayshop.com, with the following results:

sdhc 8GB - Class 6 - Kingston
Code:
Nokia-N800-26:~# ./hdparm -Tt /dev/mmcblk0p1

/dev/mmcblk0p1:
 Timing cached reads:   240 MB in  2.00 seconds = 119.87 MB/sec
 Timing buffered disk reads:   38 MB in  3.12 seconds =  12.20 MB/sec
sdhc 4GB - High Speed Class 4 (118x)
Code:
Nokia-N800-26:~# ./hdparm -Tt /dev/mmcblk1p1

/dev/mmcblk1p1:
 Timing cached reads:   244 MB in  2.00 seconds = 122.03 MB/sec
 Timing buffered disk reads:   38 MB in  3.09 seconds =  12.28 MB/sec
both of those were the 3rd of 3 runs as suggested by the hdparm manpage, over ssh to the n800. clearly as others have written the class 6 isn't worth it, at least for reads on the n800.

please post your own card details and numbers so I can make better choices next time.

oh yes, I'm using the updated kernel from http://intr.overt.org/4.2007.26-mmc-kernel/
Code:
Nokia-N800-26:~# cat /proc/version
Linux version 2.6.18-omap1 (maemo@ubuntu-maemo) (gcc version 3.4.4 (release) (CodeSourcery ARM 2005q3-2)) #2 Sun Jul 22 11:29:39 PDT 2007
and boot off of the 8gb card in the internal slot.

anyone suggest a preferred write speed tester?

rob.
 
Posts: 1 | Thanked: 0 times | Joined on Aug 2007
#2
0 is a Ridata 2gb labeled "PRO 150X"
1 is a 4 gig PNY that came labeled class 4 or something like that.

/dev/mmcblk1p1:
Timing cached reads: 236 MB in 2.01 seconds = 117.66 MB/sec
Timing buffered disk reads: 18 MB in 3.28 seconds = 5.48 MB/sec

/dev/mmcblk0p1:
Timing cached reads: 240 MB in 2.01 seconds = 119.69 MB/sec
Timing buffered disk reads: 18 MB in 3.15 seconds = 5.72 MB/sec
 
Posts: 3,401 | Thanked: 1,255 times | Joined on Nov 2005 @ London, UK
#3
joe.rock - you need to state which firmware/kernel you are using.... judging bye your slow SDHC performance it looks like stock 4.2007.26-8 but could be due to your card not supporting high speed mode.
 
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#4
Firmware: Stock 4.2007.26-8

Internal slot, Transcend 4GB Class 2 SDHC
Code:
/home/user # ./hdparm -Tt /dev/mmcblk0p1

/dev/mmcblk0p1:
 Timing cached reads:   240 MB in  2.00 seconds = 119.80 MB/sec
 Timing buffered disk reads:   16 MB in  3.22 seconds =   4.97 MB/sec
External slot, Transcend 4GB Class 2 SDHC
Code:
/home/user # ./hdparm -Tt /dev/mmcblk1p1

/dev/mmcblk1p1:
 Timing cached reads:   238 MB in  2.01 seconds = 118.13 MB/sec
 Timing buffered disk reads:   16 MB in  3.01 seconds =   5.32 MB/sec
 
Posts: 3,401 | Thanked: 1,255 times | Joined on Nov 2005 @ London, UK
#5
Firmware: High speed community 4.2007.26-8 kernel

Internal slot, Transcend 4GB Class 2 SDHC (48Mhz, wide bus), FAT32
Code:
/home/user # ./hdparm -Tt /dev/mmcblk0p1

/dev/mmcblk0p1:
 Timing cached reads:   228 MB in  2.00 seconds = 113.92 MB/sec
 Timing buffered disk reads:   24 MB in  3.21 seconds =   7.48 MB/sec
I have an ext2 second partition on the internal card which interestingly gives better performance:

Code:
/home/user # ./hdparm -Tt /dev/mmcblk0p2

/dev/mmcblk0p2:
 Timing cached reads:   220 MB in  2.00 seconds = 109.73 MB/sec
 Timing buffered disk reads:   30 MB in  3.03 seconds =   9.91 MB/sec
External slot, Transcend 4GB Class 2 SDHC (48Mhz, wide bus), FAT32
Code:
/home/user # ./hdparm -Tt /dev/mmcblk1p1

/dev/mmcblk1p1:
 Timing cached reads:   224 MB in  2.01 seconds = 111.44 MB/sec
 Timing buffered disk reads:   24 MB in  3.18 seconds =   7.54 MB/sec

Last edited by Milhouse; 2007-08-18 at 02:54.
 
penguinbait's Avatar
Posts: 3,096 | Thanked: 1,525 times | Joined on Jan 2006 @ Michigan, USA
#6
sdhc 8GB - Class 6 - Kingston

Code:
Nokia-N800-26:~# ./hdparm -Tt /dev/mmcblk0p1

/dev/mmcblk1p2:
Timing cached reads: 242 MB in 2.00 seconds = 120.25 MB/sec
Timing buffered disk reads: 38 MB in 3.04 seconds = 12.50 MB/sec

updated kernel listed in this post

mounted on /usr/local
 
Posts: 64 | Thanked: 9 times | Joined on Jun 2007 @ abuja, nigeria (currently)
#7
so seems like class 4 is worth it over class 2, if you are using the updated kernel.

rob.
 
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Posts: 87 | Thanked: 1 time | Joined on Mar 2006
#8
Testing internal Flash gives me a respectable result.
Code:
/dev/mtdblock4:
 Timing cached reads:   206 MB in  2.00 seconds = 102.83 MB/sec
 Timing buffered disk reads:   42 MB in  3.08 seconds =  13.66 MB/sec
How could that be? We all know that booting from mmc is boosting read performance.
Still on 51-6 with the SDHC kernel although I'm only running non-SDHC cards still.
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Posts: 3,401 | Thanked: 1,255 times | Joined on Nov 2005 @ London, UK
#9
There's no difference between a Class 4 and a Class 6 card... perhaps the N800 becomes the bottleneck at around that speed.

Before declaring that Class 4 is faster than Class 2 I think we need to see more Class 2 results from manufacturers other than Transcend.

In previous tests with dd my Transcend 8GB SDHC C2 cards achieved a transfer rate of 11.5MB/s... I didn't bother posting the 8GB results here as when testing with hdparm, the 8GB card turned in the same results as the 4GB card which I had already posted (ie. 7.5MB/s). This surprised me, and I'm not sure why my Transcend cards are now slower than they appeared to be in the past - maybe dd isn't accurate, or maybe hdparm isn't accurate...

The fact that I obtained two different results for the same card when accessing different partitions (and filesystems) suggests that hdparm isn't testing the raw performance of the card at all. Instead it appears to be testing the performance of the filesystem. Different block sizes in a VFAT partition may thus play a role in determining the figures returned by hdparm, and I'm sceptical about it's accuracy compared to dd.
 
Posts: 2,152 | Thanked: 1,490 times | Joined on Jan 2006 @ Czech Republic
#10
Originally Posted by tolou View Post
How could that be? We all know that booting from mmc is boosting read performance.
jffs2 filesystem is compressed and has big overhead. By using device you are reading compressed data blocks directly. Try to read/write files. dd and time commands may be better for this, examples can be found in this forum.
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