1. This forum section is a read-only archive which contains old newsgroup posts. If you wish to post a query, please do so in one of our main forum sections (here). This way you will get a faster, better response from the members on Motherboard Point.

Are SSDs always rubbish under winXP?

Discussion in 'Embedded' started by Peter, Feb 25, 2012.

  1. Peter

    Peter Guest

    I have installed a number of SSDs in desktops (24/7 operation) and all
    failed within a year or so.

    Example:
    http://www.crucial.com/store/partspecs.aspx?IMODULE=CT256M4SSD2

    They get replaced under warranty but the result is still rubbish, not
    to mention hassle, loss of data (we have tape backups but it's still a
    hassle). It seems that specific files (specific locations in the
    FLASH) become unreadable. The usual manifestation is that the disk
    becomes unbootable (sometimes NTLDR is not found; those are fixed
    using the Repair function on the install CD).

    Just now I have fixed one PC which used to simply reboot (no BSOD) and
    then report "no OS found" but if one power cycled it, it would start
    up OK. Then it would run for maybe an hour before doing the same. That
    was a duff Crucial 256GB SSD too - £400 original cost. I put a 500GB
    WD hard drive in there (using the same motherboard SATA controller)
    and it is fine.

    Years ago, on a low power PC project which shut down its hard drives,
    I did some research on what types of disk access windows does all the
    time and how they can be stopped. It turns out that it accesses the
    registry c. once per second, and it is a write, not just a read. On
    top of that are loads of other accesses, but these tend to die out
    after a long period of inactivity, and in an embedded app you can
    strip out various processes anyway. But the registry write cannot be
    disabled (in fact on a desktop O/S most things can't be) and even at
    ~100k writes per day to the same spot, this is going to wear out a
    specific FLASH area pretty quick. They are good for OTOO 10M-100M
    writes.

    But don't these SSDs have a microcontroller which is continually
    evening out the wear, by remapping the sectors?

    Their performance is great, especially if you get one with a 6gbit/sec
    SATA interface and a quality fast controller (Adaptec) to match that.
    I've seen 10x speedups in some functions.

    I gather that under win7 things are done differently (it supports the
    TRIM function, but that's unrelated to wear spreading AIUI) but for
    app compatibility reasons, etc, we use XP.

    OTOH I have installed 3 SSDs, much smaller at 32GB, in XP laptops, and
    all have been 100% fine. Those were made by Samsung. But those don't
    get run 24/7.

    I have a couple of 256GB SSDs which have been replaced under warranty
    but which are basically unusable for windoze (XP). Can they be used
    under say Unix (we have a couple of FreeBSD email servers)? Or is
    there some winXP driver which can continually remap the logical
    sectors?
     
    Peter, Feb 25, 2012
    #1
    1. Advertisements

  2. Peter

    mike Guest

    If you just dropped in the drive, you got what you'd expect.
    There are numerous webpages on tweaks for SSD drives.

    EWF might be relevant.
     
    mike, Feb 25, 2012
    #2
    1. Advertisements

  3. Peter

    Mel Wilson Guest

    I did a system that used Debian Linux with small SSDs and we eliminated the
    swap partition and set the filesystem not to update inodes on access. We
    lost no SSDs in normal operation (lost one to a power-supply accident), but
    we'd only logged about a year of use in two prototypes. Good statistics
    would want more samples than that.

    Mel.
     
    Mel Wilson, Feb 25, 2012
    #3
  4. Peter

    HectorZeroni Guest

    There is your problem. You are so stupid that you would pay that much
    for so little.

    I'd bet that it comes down to something stupid like your mobo being set
    your "SMART being on or some other ancient controller chip mode.

    Oh, and "controller" is a misnomer. The controller is on the hard
    drive. "IDE" means that the controller is on the drive. The NOBO chip is
    no more than an I/O chip, NOT a controller.

    All that proves is that you were around back when there WAS a separate
    controller, and you retained the moniker even though the facts changed.
    Points to a casual attitude toward technical details.

    SATA is slightly different, but not much. Still tertiary to the PCI
    bus though.
     
    HectorZeroni, Feb 25, 2012
    #4
  5. Peter

    HectorZeroni Guest

    It would not EVER be "to the same spot".

    You need to figure out how files get written and how the volume gets
    managed and how deleted files and the space they occupied gets managed,
    and finally, how file edits get written to a file.

    What you should have done is buy a Seagate hybrid drive. They are
    500GB (now 750), with a 4GB flash drive integrated into them.

    They give flash like performance with HD like storage capacity and
    reliability. The 500/4 is nice, but I will be getting the 750/8 soon.
     
    HectorZeroni, Feb 25, 2012
    #5
  6. Peter

    HectorZeroni Guest

    Get a true RAID 5 array up, and fill it with nine of those fuckers, and
    sector map them out, and when up to two fail, the data is still
    recoverable. You can also schedule change outs to keep things in high
    rel.

    A RAID 5 array with actual hard drives would probably perform faster,
    and would certainly be years more reliable.
     
    HectorZeroni, Feb 25, 2012
    #6
  7. Modern MLC NAND block is rated at about 1-3K program/erase cycles, SLC
    should be at about 50K. Fingers crossed that the SSD controller does full
    static wear leveling, you can do the simple math about expected endurance
    with example block size of 512KB to get the feeling.

    The SDRAM cache in the SSD offsets this a bit (by deferring the write to
    the flash memory), but exactly how much depends on controller policy.
    They have. The controller does a lot, and due to complexity there can
    always be latent bugs. And the NAND reliability is just awful, especially
    with shrinking the geometry.

    Not that it matters to trendy consumer device manufacturers.
     
    Vladimir Ivanov, Feb 25, 2012
    #7
  8. Peter

    John Larkin Guest


    Now that you mention it, USB memory sticks don't last, but hard drives
    seem to never fail. I think the semi guys are pushing flash density to
    the bleeding edge of reliability.

    You may as well buy a PC with a fast hard drive and mountains of DRAM,
    so it has lots of disk cache and doesn't thrash virtual.


    --

    John Larkin, President Highland Technology Inc
    www.highlandtechnology.com jlarkin at highlandtechnology dot com

    Precision electronic instrumentation
    Picosecond-resolution Digital Delay and Pulse generators
    Custom timing and laser controllers
    Photonics and fiberoptic TTL data links
    VME analog, thermocouple, LVDT, synchro, tachometer
    Multichannel arbitrary waveform generators
     
    John Larkin, Feb 25, 2012
    #8
  9. Peter

    HectorZeroni Guest


    Where are your stats from? I have never had one fail, and I have like
    50 of them, and I change file system types, and everything.Lots of
    thorough use.

    They are one of the few things still made with mil specs in mind, if not
    followed religiously.

    They are just now selling stacked 750 GB modules, etc. That really
    ain't all that big, and the chips use densities which get tested.
    Or the OS guys will wise up and make a segmented system which puts logs
    and other constantly modified files onto magnetic storage, whenever
    available.

    The Seagate hybrids already address these issues with their intelligent
    management of what ends up on the flash half of the hybrid.
     
    HectorZeroni, Feb 25, 2012
    #9
  10. Peter

    Peter Guest

    I have done some googling on this topic and it is quite a nasty
    suprise to learn how poor a life flash drives are *expected* to have.
    For example (can't find the URL right now) the Intel X25 SSDs can have
    only about 30TB written to the drive in its whole life. With perfect
    wear spreading, this will push every part of the drive to the flash
    write limit in something like 5 years (they reckon) of average desktop
    computer usage (they reckon).

    30TB is not all that much, over years, especially with swapfile usage.

    And if the wear spreading is working less than optimally (firmware
    bugs) then all bets are off. On the SSD forums there is a ton of stuff
    about different SSD firmware versions doing different things. I have
    to wonder who actually has a LIFE after worrying about the firmware on
    a "hard drive" :) You don't worry about firmware updates on a cooker,
    do you?

    So I am not suprised my SSDs are knackered in c. 1 year while hard
    drives seem to go on for ever, sometimes making a funny noise after ~5
    years (on a 24/7 email/web server) at which point they can be changed.
     
    Peter, Feb 25, 2012
    #10
  11. Peter

    Peter Guest

    You probably don't write terabytes to them though. Also you are
    extremely unlikely to ever go anywhere near even a very low write
    cycle limit (1000+) with a removable drive. In most usage, one does
    just ONE write to the device, in each use.

    So my other post re Intel SSD write limits. They are very suprisingly
    low.
    OK, but why does anybody use an SSD?

    I used them to make a hopefully silent PC, or one drawing little
    power. Or, in portable apps, to make a tablet computer work above
    13000ft in an unpressurised aircraft
    http://www.peter2000.co.uk/ls800/index.html

    Combining a HD with an SSD defeats both those things.

    In actual usage, I find, the SSD outperforms a HD very noticeably in
    very narrow/specific apps only, which tend to be

    - a complex app, comprising of hundreds of files, loading up, perhaps
    involving loading up thousands of records from a complicated database
    into RAM

    - any app doing masses of random database reads

    Anything involving writing is usually slower, and anything involving
    sequential reading is no quicker.
     
    Peter, Feb 25, 2012
    #11
  12. Peter

    HectorZeroni Guest

    Because electronics are way faster than physical, spinning media with
    hard latencies built in to every read and write.
     
    HectorZeroni, Feb 25, 2012
    #12
  13. Peter

    HectorZeroni Guest

    Combining the two gives you instantaneous access to the files in that
    segment, and HUGE, RELIABLE storage capacity for the greater mass of your
    data.
     
    HectorZeroni, Feb 25, 2012
    #13
  14. Peter

    John Larkin Guest

    Flash *could* be made reliable, but the fabbers go for density. Once
    they get a really reliable cell designed, they scale it down and
    multi-level it until it's flakey again.

    We only buy ranges ("cookers") that don't have electronics. That makes
    them cost about 4x as much, but that's worth it.


    --

    John Larkin, President Highland Technology Inc
    www.highlandtechnology.com jlarkin at highlandtechnology dot com

    Precision electronic instrumentation
    Picosecond-resolution Digital Delay and Pulse generators
    Custom timing and laser controllers
    Photonics and fiberoptic TTL data links
    VME analog, thermocouple, LVDT, synchro, tachometer
    Multichannel arbitrary waveform generators
     
    John Larkin, Feb 25, 2012
    #14
  15. Peter

    Nico Coesel Guest

    A decent SSD should have wear leveling but if you don't disable the
    virtual memory the SSD will wear out quickly.
    Unless you disable the virtual memory XP swaps everything it can to
    the hard disk to have as much unused memory as possible. Its a real
    nuisance. Just install 2GB of memory and disable swap to get maximum
    performance. The performance gain is huge.
     
    Nico Coesel, Feb 25, 2012
    #15
  16. Peter

    John Larkin Guest

    16G, if you intend to compile FPGAs.


    --

    John Larkin, President Highland Technology Inc
    www.highlandtechnology.com jlarkin at highlandtechnology dot com

    Precision electronic instrumentation
    Picosecond-resolution Digital Delay and Pulse generators
    Custom timing and laser controllers
    Photonics and fiberoptic TTL data links
    VME analog, thermocouple, LVDT, synchro, tachometer
    Multichannel arbitrary waveform generators
     
    John Larkin, Feb 25, 2012
    #16
  17. Peter

    WoolyBully Guest

    You're a dork.
     
    WoolyBully, Feb 26, 2012
    #17
  18. Peter

    John Larkin Guest

    And you're AlwaysWrong.


    --

    John Larkin, President Highland Technology Inc
    www.highlandtechnology.com jlarkin at highlandtechnology dot com

    Precision electronic instrumentation
    Picosecond-resolution Digital Delay and Pulse generators
    Custom timing and laser controllers
    Photonics and fiberoptic TTL data links
    VME analog, thermocouple, LVDT, synchro, tachometer
    Multichannel arbitrary waveform generators
     
    John Larkin, Feb 26, 2012
    #18
  19. Peter

    WoolyBully Guest

    Only a 12 year old mind needs to call names.

    My description of you is not a name, it is a behavioral observation.
    That is beside the fact that you do not know the first thing about how
    they are making memory arrays these days, much less any reliability
    figures, you lying POS.
     
    WoolyBully, Feb 26, 2012
    #19
  20. Peter

    John Larkin Guest

    Wrong again.


    --

    John Larkin, President Highland Technology Inc
    www.highlandtechnology.com jlarkin at highlandtechnology dot com

    Precision electronic instrumentation
    Picosecond-resolution Digital Delay and Pulse generators
    Custom timing and laser controllers
    Photonics and fiberoptic TTL data links
    VME analog, thermocouple, LVDT, synchro, tachometer
    Multichannel arbitrary waveform generators
     
    John Larkin, Feb 26, 2012
    #20
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.