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.