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Re: Big endian vs Little endian and Network performance

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  • Bob Cox
    In article , ... For comparison, on one of my 266MHz OpenDebianSlug slugs: solaria:~# hdparm -t -T /dev/sda /dev/sda /dev/sda
    Message 1 of 45 , Jul 1, 2006
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      In article <44A5A0F4.6030603@...>,
      David Given <dg@...> wrote:

      > Is there any chance you could get hdparm and try this:
      >
      > hdparm -t -T /dev/sda /dev/sda /dev/sda /dev/sda /dev/sda
      >
      > (Yes /dev/sda is supposed to be repeated five times.) That'll do a sequence=
      > of
      > (harmless) low-level benchmarks of the drive alone, without touching the
      > network, filesystem, etc --- I'd be very interested to see the results.

      For comparison, on one of my 266MHz OpenDebianSlug slugs:

      solaria:~# hdparm -t -T /dev/sda /dev/sda /dev/sda /dev/sda /dev/sda

      /dev/sda:
      Timing cached reads: 212 MB in 2.00 seconds = 106.00 MB/sec
      Timing buffered disk reads: 32 MB in 3.07 seconds = 10.42 MB/sec

      /dev/sda:
      Timing cached reads: 216 MB in 2.03 seconds = 106.40 MB/sec
      Timing buffered disk reads: 32 MB in 3.04 seconds = 10.53 MB/sec

      /dev/sda:
      Timing cached reads: 212 MB in 2.01 seconds = 105.47 MB/sec
      Timing buffered disk reads: 34 MB in 3.09 seconds = 11.00 MB/sec

      /dev/sda:
      Timing cached reads: 216 MB in 2.02 seconds = 106.93 MB/sec
      Timing buffered disk reads: 34 MB in 3.09 seconds = 11.00 MB/sec

      /dev/sda:
      Timing cached reads: 216 MB in 2.02 seconds = 106.93 MB/sec
      Timing buffered disk reads: 34 MB in 3.10 seconds = 10.97 MB/sec
      solaria:~#

      I assume that 11 MB/sec is around 88 Mb/sec ?

      The hard drive is a Western Digital WD200JB. The IDE/USB interface is
      one of these:

      http://www.directusbstore.co.uk/cnb/shop/directusbstore?productID=223&op=catalogue-product_info-null&prodCategoryID=30

      HTH

      --
      Bob Cox. Stoke Gifford, near Bristol, UK.
      My slugpage: http://slug.bobcox.com/
    • Yann E. MORIN
      Brian, All, ... Looks like it s OK. :-) ... [--SNIP--] ... So hand-adding swap only when you need it for sure (compilation, install of packages, etc..) Yes,
      Message 45 of 45 , Jul 3, 2006
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        Brian,
        All,

        On Monday 03 July 2006 002, Brian Wood wrote:
        > [Don't know if changing the subject will preserve the threading or not]

        Looks like it's OK. :-)

        > On Jul 2, 2006, at 3:37 PM, Yann E. MORIN wrote:
        > >> Something like this:
        > >> http://www.geeks.com/details.asp?invtid=77P1636&cat=HDD
        > > Hmm, donuts!... :-) Anyway i would not entrust flash-based hard-
        > > drive, wether
        [--SNIP--]
        > I'll grant all of that, but once I get the thing going I hardly touch
        > swap at all, and that thing does seem *fast*, but I suspect the
        > limiting factor is the IDE-USB transition, so it might not be any
        > faster than a normal 4200 rpm drive.

        So hand-adding swap only when you need it for sure (compilation, install
        of packages, etc..) Yes, why not. Then that's not that bad. But still I'm
        amazed at the figures they show. Seems pretty fast for flash.

        > If the cycle number is correct on that, and they are "spreading the
        > load", I could live with having to replace the drive every year, if
        > it actually gave me a speed boost.

        Surely they are doing wear-leveling on [dr]ecent flash memories.

        > I suppose the only way to know for sure is to buy one and play with
        > it, $99 for a 2GB, oh well, it's only money.

        Be my guest. Tell us about your conclusions! :-)

        > > Maximum load when receiving: 0.94. That's really, really _big_.
        > > So what does that _mean_? It looks like we _are_ CPU-bound on the
        > > slug, and thus
        > > it can not even sustain receiving more than around 48Mibps. That is
        > > _receiving_.
        > I guess I'm not surprised, for <$100 :-)

        Yes, I can't imagine with a 133Mhz slug... :-/ Anyway, that's a good buy,
        and you get what you pay for: a good little hardware really easy to play with,
        a NAS that will fulfill most of your desires reagarding file access (except if
        you are dumb enough to have your /home on it (I am!)) and a little box that is
        quite good-looking after all.

        > > Looking at the WiKi, there is a section on using the DMA
        > > accelerations from the
        > > NPEs. That could help, but yet... :-/
        > So it looks like 48Mibps is about it, and the most helpful
        > improvement would probably be from a better network driver.

        Such as an USB-to-ethernet adapter, as David suggests. But again, we might
        see a bottleneck between usb-storage and usb-ethernet... :-/

        Anyway, if anyone can conduct the same tests with such a device, please tell
        us.

        > Much thanks for the information.

        You're welcome. I was enlighten as well by this very instructive experiment.
        At last I know how I can entrust my slug regarding file-serving speeds.

        Regards,
        Yann E. MORIN.

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