dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5331
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: SD Card performance in R-Pi onboard slot

Tue Aug 28, 2012 9:04 pm

pfqueiros wrote:

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 Timing cached reads:   118 MB in  2.02 seconds =  58.52 MB/sec
 Timing buffered disk reads:  56 MB in  3.02 seconds =  18.52 MB/sec
These are very low values, no :?:
No. They are pretty good.

tk321
Posts: 31
Joined: Sat Jun 02, 2012 6:09 pm
Location: UK

Re: SD Card performance in R-Pi onboard slot

Tue Aug 28, 2012 9:48 pm

dom wrote: sdhci-bcm2708.enable_llm=1 sdhci-bcm2708.sync_after_dma=0
This seems to have no impact on the hdparm benchmark (raspbian, Kingston 8GB class 6). I get before and after something like:

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 # hdparm -tT /dev/mmcblk0
  Timing cached reads:   300 MB in  2.00 seconds = 149.87 MB/sec
  Timing buffered disk reads:  60 MB in  3.08 seconds =  19.46 MB/sec

pfqueiros
Posts: 28
Joined: Sat Aug 04, 2012 3:04 pm
Location: Guimarães, Portugal

Re: SD Card performance in R-Pi onboard slot

Wed Aug 29, 2012 9:06 pm

Yeah, that's why I said my values are poor. How can I improve them?

bluegroper
Posts: 8
Joined: Mon Sep 10, 2012 8:09 pm

Re: SD Card performance in R-Pi onboard slot

Sun Sep 30, 2012 11:57 am

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[email protected]:~# hdparm -t /dev/mmcblk0
/dev/mmcblk0:
 Timing buffered disk reads:  62 MB in  3.07 seconds =  20.22 MB/sec
Stock Ra Pi. No fancy tweaks.
Ra Pi, headless, Patriot LX Pro Class 10 SD card 16GB, Realtek 150Mbps micro 802.11n USB 2.0 wireless network adapter

Stabby666
Posts: 1
Joined: Thu Nov 22, 2012 4:13 pm

Re: SD Card performance in R-Pi onboard slot

Thu Nov 22, 2012 4:16 pm

What I can gather from this is that ~20MB/sec is around the maximum that's likely to be seen using the SDCard slot. So it's not worth going for any SDCard that's much above this speed - certainly there's no point in getting 85MB/sec class 10 cards!

jrflop
Posts: 9
Joined: Tue Oct 14, 2014 11:59 pm

Re: SD Card performance in R-Pi onboard slot

Wed Oct 15, 2014 12:45 am

Hi,
I don't know if this is the good place for this. I've noticed a well hidden problem with a specific SD card (and no problem with the others)

Since a very long time now, I have noticed some problems with my Raspberry when I'm copying a big amount of data into it (by FTP, for example, but not only).
For a custom FTP Server for movies, it's really very annoying.

When it blocks, if a working SSH session is opened, if I type something and press enter, I get "bus error" and the session freeze.
When it blocks, I cannot open anything (because every access to the SD card became impossible) so I just have to unplug it and plug it again.
No problem are written into any log because you know (no more SD card, no more log).

But yesterday, it was too much (I hate things that ships as much progress to finally fail in such a unacceptable and unjustified way dozen and dozen and dozen of times for months now) - I told myself that if I'm not able to stop that problem now, there is no way I keep my raspberry one more day :evil: too much is too much.

I discovered that the problem only appears when I'm using the Samsung 32GB SDHC Plus Class 10 Memory Card
When I'm switching to a Class 4 card (Verbatim, same size), after trying all the day to make my raspberry explode, no more "bus error". I wonder if it's not a little bit slower but there is absolutely no more crash :D
No problems too with a Class 2 16GB card (PNY)

The bad card :
http://www.samsung.com/in/consumer/memo ... B-SPBGC/CN

On my computer (USB Card Reader) absolutely no problem when (over)writting the entire card.

Do anybody of you have a similar SD card ?

Can the problem be confirmed on the Raspberry ? (Try to fill the SD card with big files and fast bandwidth)

Is this a bug into the Raspberry with Class 10 cards, or anything else already known ?

I hope this observation will be useful for you and for everybody who look for the cause of the same problem.

Because this kind of problems are able to turn me mad when I don't know what's going on :roll: and when some thing turn me mad, a quick solution is the only way for the thing to remain in one piece ! My Raspberry is lucky ;) I hope others will be too !

jrflop
Posts: 9
Joined: Tue Oct 14, 2014 11:59 pm

Re: SD Card performance in R-Pi onboard slot

Wed Oct 15, 2014 7:30 pm

Something new :

I've decided to reproduce the problem with the same SD card on another Raspberry Pi (connected to a full HD TV)

When it blocks, I have :

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[email protected] ~$ [ 2262.340164] EXT4-fs error (device mmcblk0p2) in ext4_reserve_inode_write:4862: Journal has aborted
[ 2262.358808] EXT4-fs error (device mmcblk0p2): ext4_journal_check_start:56: 
[ 2262.370935] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000007
And some more lines after (if you are motivated enough to copy by hand ;) )
http://imageshack.com/a/img910/3972/ObLRhL.jpg

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DougieLawson
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Contact: Website Twitter

Re: SD Card performance in R-Pi onboard slot

Wed Oct 15, 2014 7:40 pm

That SDCard is trashed. Time to spend a tenner and get a fresh one.
Note: Having anything humorous in your signature is completely banned on this forum. Wear a tin-foil hat and you'll get a ban.

Any DMs sent on Twitter will be answered next month.

This is a doctor free zone.

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5331
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: SD Card performance in R-Pi onboard slot

Wed Oct 15, 2014 7:41 pm

jrflop wrote: I discovered that the problem only appears when I'm using the Samsung 32GB SDHC Plus Class 10 Memory Card
When I'm switching to a Class 4 card (Verbatim, same size), after trying all the day to make my raspberry explode, no more "bus error". I wonder if it's not a little bit slower but there is absolutely no more crash :D
No problems too with a Class 2 16GB card (PNY)
We have seen a problem with recent fast class 10 cards. A potential fix has been on the 3.17 kernel for testing and i'll include it in the next rpi-update.
I'll report here when update is pushed out.

jrflop
Posts: 9
Joined: Tue Oct 14, 2014 11:59 pm

Re: SD Card performance in R-Pi onboard slot

Wed Oct 15, 2014 8:40 pm

Thank you for your answers, so I keep this card empty and available to do the test when the update will be pushed-out

Some more information (just in case it's useful) :

-Outside the raspberry, this SD card is perfectly well working (for writing and reading)
I understand you could have some doubt but I have tested with my computer's USB card reader several times all over the surface : constant speed and no disconnection.

-On the Raspberry Pi, the crash happen anywhere on the SD card (just after re-installation, if I run a big copy, the copy will never fail at the same percentage, it could be earlier or later than the previous crash, even if I re-erase the SD card and do exactly the same commands)

-My digital camera is able to do a very fast* and complete flash reset of the SD card over the entire surface (while for doing the same, my PC is writing zero by zero during half an hour without using flash erase). With all my SD cards, the first reading/writing after the kind of erase is a little bit faster. But for this case, no differences for the crashes.

-The writing bandwidth I have with the computer is approximately 15MB/s, while on the Raspberry Pi, it seems to be slower : a 12,5MB/sec Ethernet and FTP session is making pauses every few seconds; regarding the starting and ending time of writing a big file, it's about 7 or 8 MB/sec approximately.

(very fast* : 10 seconds approximately, depends of the card model and trademark)

I stay tuned ;)
See you soon !

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5331
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: SD Card performance in R-Pi onboard slot

Fri Oct 17, 2014 6:04 pm

jrflop wrote:Thank you for your answers, so I keep this card empty and available to do the test when the update will be pushed-out
It's pushed. Try rpi-update and let us know if it helps.

jrflop
Posts: 9
Joined: Tue Oct 14, 2014 11:59 pm

Re: SD Card performance in R-Pi onboard slot

Sun Oct 19, 2014 2:40 pm

Hi,

After a new installation of 2014-09-09-wheezy-raspbian.img and upgrade using apt-get, (still into the involved Samsung 32 GB Class 10 + U1 card), the problem still exists.

File system expand using raspi-config
reboot using raspi-config

apt-get update
apt-get upgrade (with Yes)
reboot
apt-get install proftpd

And a big writting into /home/pi, failing after somes minutes (this time, after 8,479,182,848 bytes) - Kernel Panic like before

Is there anything I must do in a different way to do the test ?

Remark : I think that, with a limited bandwidth, there is no crash (like an old WiFi computer sending at 2 MBytes/s for example), but I will try to confirm this, because I need to do more test to be sure of this

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jbeale
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Re: SD Card performance in R-Pi onboard slot

Sun Oct 19, 2014 2:56 pm

Did you do 'sudo rpi-update' ?

Not the same as 'sudo apt-get ...'

jrflop
Posts: 9
Joined: Tue Oct 14, 2014 11:59 pm

Re: SD Card performance in R-Pi onboard slot

Sun Oct 19, 2014 4:37 pm

Thanks for your answer, I didn't know this command, so rpi-update is a kind of bios update (much better, I was thinking, for fixing this kind of low level / hardware problems !)

I'm now running the test, with the new firmware. I keep you informed in couple of minutes (hours at most).

EDIT :

After more than 40 Gigabytes written into the SD card (with one big delete for free space ;) ) I think that the problem is solved by this rpi-update.

Congratulation and thank you for this repair !

I hope this will now be better for a lot, lot lot of users around the world.

But I don't know if rpi-update is a really known command (may be I'm not often enough on Raspberries websites to know it, but it would be interesting to have it on raspi-config. It's the first time I run this command)

dom
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 5331
Joined: Wed Aug 17, 2011 7:41 pm
Location: Cambridge

Re: SD Card performance in R-Pi onboard slot

Sun Oct 19, 2014 6:41 pm

jrflop wrote:After more than 40 Gigabytes written into the SD card (with one big delete for free space ;) ) I think that the problem is solved by this rpi-update.

Congratulation and thank you for this repair ![/b]
I hope this will now be better for a lot, lot lot of users around the world.

But I don't know if rpi-update is a really known command (may be I'm not often enough on Raspberries websites to know it, but it would be interesting to have it on raspi-config. It's the first time I run this command)
Glad it has helped.

rpi-update is used for getting the very latest firmware. Normally this is used by people who like testing new features and reporting bugs, before the update is pushed out more widely.
However if someone is hitting a specific bug (like yourself), then trying the latest firmware makes sense.

Periodically we update the firmware you get from apt-get, and on a new raspbian scard image, so you will likely find this fix is available through the more common updates in a month or two.

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