test your sd card read speeds on n800
 

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
sdhc 4GB - High Speed Class 4 (118x)
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/
and boot off of the 8gb card in the internal slot.

anyone suggest a preferred write speed tester?

rob.

Re: test your sd card read speeds on n800
 

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

Re: test your sd card read speeds on n800
 

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.

Re: test your sd card read speeds on n800
 

Firmware: Stock 4.2007.26-8

Internal slot, Transcend 4GB Class 2 SDHC
External slot, Transcend 4GB Class 2 SDHC

Re: test your sd card read speeds on n800
 

Firmware: High speed community 4.2007.26-8 kernel

Internal slot, Transcend 4GB Class 2 SDHC (48Mhz, wide bus), FAT32
I have an ext2 second partition on the internal card which interestingly gives better performance:

External slot, Transcend 4GB Class 2 SDHC (48Mhz, wide bus), FAT32

Re: test your sd card read speeds on n800
 

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

Re: test your sd card read speeds on n800
 

so seems like class 4 is worth it over class 2, if you are using the updated kernel.

rob.

Re: test your sd card read speeds on n800
 

Testing internal Flash gives me a respectable result.
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.

Re: test your sd card read speeds on n800
 

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.

Re: test your sd card read speeds on n800
 

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.

Re: test your sd card read speeds on n800
 

Firmware: 4.2007.26-8
Kernel: 2.6.18-omap1 (stock)
Card: SanDisk SDHC (4GB)

I guess it's time to update the kernel, huh.

Re: test your sd card read speeds on n800
 

good idea :)
hdparm uses the linux ioctls for reading blocks off disks, as I expect the filesystem layer does. it's written by the developer/maintainer of the (e)ide linux driver, and the man page is explicit about 'without any filesystem overhead' for the -t test. nonetheless, 'formatted filesystem' doesn't equal 'fdisk parameters' and I don't see hdparm or anything else yet as the ideal benchmark for this. I think others have posted here about logic in the cards to re-map memory blocks as they die, so there's probably a lot inside these black boxes that we won't be able to know about. there's also the point that both the benchmarking tools and the memory cards are 'imagining' a system of heads and spinning platters.

wonder if dd uses the same ioctls as well? how big were your dd tests?

both my cards are single partition ext2 filesystems tho, so can't do much testing on these different aspects. and I'm not that keen to dd a big block of data into the middle of either of them :)

rob.

Re: test your sd card read speeds on n800
 

perhaps the the sd card i/o is dispatched off to a separate bit of circuitry, while the internal flash and ram could be sharing access hardware (address and data lines)? just a guess of course...

rob.

Re: test your sd card read speeds on n800
 

About 240MB - benchmarking a dd *read* is non destructive.

Here's a link to the thread with my tests when using dd.

Re: test your sd card read speeds on n800
 

I have the official SDHC firmware. Like others, I am getting about 5.5MB/S buffered read speeds on both internal and external slots. The internal card is an older SanDisk 1GB SD. The external is the A-Data 8GB SDHC that I just bought. This is a Class 2 card, but it performs like a Class 6 in a card reader in my PC. In my N800, both cards are performing about the same. Obviously, there is a severe bottleneck in the N800.

Re: test your sd card read speeds on n800
 

Ran again, 2GB Kingston MMCMobile, VFAT (setup inside winxp)

mmc0 is mounted on /media/mmc1

then I created a 1GB ext2 filesystem on a file in /media/mmc1
/media/mmc1/1GB_file

then mount -o loop to /usr/local

mount -o loop /media/mmc1/1GB_file /usr/local


/dev/loop0:
Timing cached reads: 216 MB in 2.01 seconds = 107.24 MB/sec
Timing buffered disk reads: 30 MB in 3.01 seconds = 9.98 MB/sec
Nokia-N800-26:~# ./hdparm -Tt /dev/loop0

/dev/loop0:
Timing cached reads: 234 MB in 2.01 seconds = 116.25 MB/sec
Timing buffered disk reads: 52 MB in 3.01 seconds = 17.30 MB/sec
Nokia-N800-26:~# ./hdparm -Tt /dev/loop0

/dev/loop0:
Timing cached reads: 242 MB in 2.00 seconds = 120.85 MB/sec
Timing buffered disk reads: 52 MB in 3.14 seconds = 16.56 MB/sec

Check this out, kinda interesting?

Re: test your sd card read speeds on n800
 

yes, the bottleneck is in the firmware which does not implement the full speed the hardware is capable of. the view seems to be that this was probably done to ensure the widest compatibility for non-techy users. if you're concerned about measuring and getting the fastest speeds from your card then you have probably moved out of the initial target audience and should consider using the kernel with the speed enhancements.

rob.

Re: test your sd card read speeds on n800
 

it does seem like we can get different speeds from different regions of the card, tho really not clear what effect the ext2 on top of vfat has here :) also, what class is the MMCMobile?

I do think Milhouse/Fanoush are right - dd and their 240mb read tests will probably give a more accurate picture of card speed overall than the hdparm 2sec/3sec tests.

ideally we'd all think to do dd write tests when we first get the cards before reformatting them and loading up all our goodies.

rob.

Re: test your sd card read speeds on n800
 

A-DATA Turbo 8GB Secure Digital High-Capacity(SDHC) Flash Card Model TurboSD SDHC 8G - Retail (Class 6)
http://www.newegg.com/product/produc...82E16820211180
/dev/mmcblk1p1:
Timing cached reads: 186 MB in 2.00 seconds = 92.80 MB/sec
Timing buffered disk reads: 14 MB in 3.18 seconds = 4.40 MB/sec

second card:
/dev/mmcblk0p1:
Timing cached reads: 194 MB in 2.02 seconds = 96.26 MB/sec
Timing buffered disk reads: 14 MB in 3.10 seconds = 4.51 MB/sec

Re: test your sd card read speeds on n800
 

/dev/mmcblk1p1:
Timing cached reads: 194 MB in 2.00 seconds = 96.42 MB/sec
Timing buffered disk reads: 10 MB in 3.18 seconds = 3.14 MB/sec

/dev/mmcblk1p2:
Timing cached reads: 192 MB in 2.02 seconds = 95.27 MB/sec
Timing buffered disk reads: 14 MB in 3.03 seconds = 4.62 MB/sec


OK, so why is my benchmark so darn slow!?! On my N810 I have a 4Gig Class 6 SD brand card. I have dual boot installed and currently booted into my SD card.

This has prompted me to look for the 48MHz mmc hack and I've installed the "Modified initfs with onscreen boot menu and usb network recovery" from http://fanoush.wz.cz/maemo/ which I thought had the 48MHz hack in there. When I got into "About" I see that I have version 2.2007.51-3 but on Fanoush's website it says "2.2007.50-2" so do I not have it installed then? If so, how am I dual booting?

I'm confused, any help would be great. Basically, I'm sick of how damn slow everything loads and was hoping that by having a faster SD card, booting from it, getting away from the jffs2 OS, and launching programs from my SD card, everything would load 25% faster or better.

Re: test your sd card read speeds on n800
 

The 48Mhz sd hack is in the kernel. It is also noted, in OS2008, you have to turn off the cpufreq to get it to the full speed.

Re: test your sd card read speeds on n800
 

Thanks for the reply qwerty12. So that sucks then about the cpu freq down for sd speed. So with all of the hacks you have on your NIT, what speed is your sd card with this benchmark?

Is there a program where I could toggle the cpu in favor of sd speed? Maybe an auto throttling background task?

Re: test your sd card read speeds on n800
 

I wish I had all those hacks back :). I'm still recovering from flashing.

You would have to flash Fanoush's kernel (either from his website or the one in the rotation thread if you like rotation too, fanoush's one, not jott's one)

Then you can echo these as root:
echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
echo 400000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq

That will make the cpu run at it's full speed and bring the battery down.

To bring it back to normal;
echo 165000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
echo ondemand > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

I just received a class 2 8GB SD card so after hacking, I'll post the speed of it :)

Re: test your sd card read speeds on n800
 

qwerty12,

Man, you have made a happier person with information. The whole device is snappier and more usable at this point thanks to the speed up. I'm leaving the system in the faster speed because it really hasn't diminished my battery life much at all from a normal days use. But, the speed difference is there and makes things a little more pleasant. Thanks again. The NIT also just seems to run aplications faster such as my emulators and normal web browsing. Maybe it's a placebo but I'm think that since the unit doesn't auto-throttle the processor, it just allows a smoother/faster day to day operation.

Here are my new results after running the two command lines from Xterm:

/dev/mmcblk1p1:
Timing cached reads: 204MB in 2.01 seconds = 101.25 MB/sec
Timing buffered disk reads: 26 MB in 3.00 seconds = 8.66 MB/sec
/dev/mmcblk1p2:
Timing cached reads: 200MB in 2.00 seconds = 99.95 MB/sec
Timing buffered disk reads: 38 MB in 3.00 seconds = 12.66 MB/sec


My old numbers (For reference):
/dev/mmcblk1p1:
Timing cached reads: 194 MB in 2.00 seconds = 96.42 MB/sec
Timing buffered disk reads: 10 MB in 3.18 seconds = 3.14 MB/sec
/dev/mmcblk1p2:
Timing cached reads: 192 MB in 2.02 seconds = 95.27 MB/sec
Timing buffered disk reads: 14 MB in 3.03 seconds = 4.62 MB/sec

Re: test your sd card read speeds on n800
 

not totally related....but sorta is....i tested using hdtac the internal drive on the n800...only got 5 mb/s but whence on an external reader the same card got 20.2 mb/s my version on the about product is 2.2007.51-3 didnt run the hdparm yet

Re: test your sd card read speeds on n800
 

That looks like a good setup. When you do get hdparm on your device and test it, please post what you find. I would like to know if it reports these same smoking speeds.