HDD size or speed for video?

Discussion in 'Amateur Video Production' started by David Lewis, Nov 12, 2003.

  1. David Lewis

    David Lewis Guest

    Hi All

    I am putting together a new computer system with the most demanding task
    expected to be desktop video.

    Someone said not to worry about 10,000 rpm drives as you are better off with
    larger 7200rpm drives for the equivalent money.The theory is that you are
    laying down large chunks of continuous info so do not need fast spinning
    disc to be "seeking" (provided you have defragged) and that read - write
    speeds will be dependent on other things.So which is more important for
    video..disc size or spin speed?

    Also do RAID O configurations offer significant enhancements to data
    throughput (is it worth the extra cost) ?
    I understand the theoretical advantages but would love to hear from people
    with real world experience.

    Thanks

    Regards

    David
     
    David Lewis, Nov 12, 2003
    #1
    1. Advertisements

  2. Unless you're dealing with uncompressed video, any large modern drive is
    plenty fast enough so your best bet is to focus on the cost per unit of
    storage. 160gig drives seem to be the sweet spot in terms of lowest
    cost these days. If you need lots of storage, any of the 3Ware SATA
    RAID cards + however many disks you can afford make for a lightning fast
    array at bargain basement prices.

    Cheers,

    C
     
    Chris Mauritz, Nov 12, 2003
    #2
    1. Advertisements

  3. David Lewis

    thrillcat Guest

    http://tinyurl.com/upco


    Best Buy has this 250gig drive for sale at $250, plus $90 in rebates,
    bringing the final cost to $160.

    Last time I bought a drive, CompUSA matched Best Buy's "after rebate price"
    out the door, so I'm going today to see if they'll sell me this drive for
    $160...
     
    thrillcat, Nov 12, 2003
    #3
  4. David Lewis

    drifter Guest

    It depends what type of video files you are capturing...
    I can do analog video caputre (HUffYuv codec @22MB/s) on
    7200RPM/ATA100 hard drive. Size of hard disk cache has no
    impact when dealing with multi GB files.
    OTOH, I routinely capture DV(3.5MB/s) to my laptop on 4200RPM harddrive
    with no dropped frames.
     
    drifter, Nov 12, 2003
    #4
  5. David Lewis

    David Lewis Guest

    OK thanks and good to know.I mainly need DV capture but occasional analogue
    stuff.
    If you do the maths, I think I read somewhere,raw analogue uncompressed
    broadcast video is around 25MB/sec and from say VCR is 22MB/sec.So from what
    your saying I should be fine with 7200 rpm drives for capture purposes.

    Things like rendering I presume have nothing to with hard disc speed so once
    again there would appear to be no need for disc in excess of 7200rpm?The
    only yhing that still puzzles me a bit is why ultra fast SCSI drives/systems
    are often recommended for desktop video?

    Thanks again
     
    David Lewis, Nov 14, 2003
    #5
  6. David Lewis

    Nomen Nescio Guest

    Hard disc speed has almost nothing to do with render speed.
    Some of it is just legacy information when IDE drives didn't cut it for
    desktop video.

    And some of it is when you are doing something like working with multiple
    streams of uncompressed video, ATA drives still won't cut it.
     
    Nomen Nescio, Nov 14, 2003
    #6
  7. David Lewis

    David Lewis Guest


    Ok thanks I suspected as much.I will be setting up with SATA drives in RAID
    0 for video,and possibly even that is overkill?
     
    David Lewis, Nov 14, 2003
    #7
  8. No single drive solution is going to be able to reliably capture
    uncompressed video. If that's one of your design requirements, you
    might want to try something like the Abit IC7 motherboard which includes
    a 4-port SATA RAID controller on the motherboard. Pop a few SATA drives
    in and you should be more than able to capture uncompressed video and
    take care of the more mundane firewire captures.

    Good luck!

    Cheers,

    C
     
    Chris Mauritz, Nov 15, 2003
    #8
  9. David Lewis

    David Lewis Guest


    Thanks Chris.I am looking at the ASUSP4C800 Deluxe which also has a
    (Promise)4 port SATA RAID Controller and using two 160 GB dedicated capture
    drives in RAID 0. The drives will be 7200rpm and by the sounds of it plenty
    for my needs.

    Cheers
     
    David Lewis, Nov 15, 2003
    #9
  10. David Lewis

    Samuel Paik Guest

    NTSC: 720*480*2*29.97 = 20,715,264 bytes/sec. There are a number
    of current ATA drives that can sustain 20 MBytes/sec across the
    entire disk today. A year ago I had a system which could easily
    capture uncompressed video but could barely compress to
    low Q MJPEG (only had a Duron 750 in it).
     
    Samuel Paik, Nov 15, 2003
    #10
  11. I'm not sure that a single drive is capable of sustaining that
    performance over the term of a recording of, say, 30 minutes. Or has
    the old thermal recalc overhead been eliminated? For such throughput, a
    much better approach will be one or another of the RAID schemes.
     
    William Meyer, Nov 16, 2003
    #11
  12. If you understand the theory, then the performance advantage of
    splitting of files across two drives should also be clear. Less clear
    to many is that simple striping actually *degrades* reliability, and is
    best suited to short-term storage, hence its widespread use in desktop
    editing, where projects come and go.

    If performance is crucial, and reliable long-term storage is also
    needed, then far better to explore RAID5.
     
    William Meyer, Nov 16, 2003
    #12
  13. David Lewis

    DK Guest

    My understanding of the new drives is that thermal recalibration is a thing
    of the past.
     
    DK, Nov 16, 2003
    #13
  14. Good to know. I haven't had occasion to worry about it, as I don't deal
    with uncompressed video work.
     
    William Meyer, Nov 16, 2003
    #14
  15. David Lewis

    Samuel Paik Guest

    I believe I have done so (1 hour+), but since I don't have that
    system any more so I can't reproduce it to verify.
    I believe hard drive manufacturers are using a different strategy
    than periodic thermal recals for most of the time.
     
    Samuel Paik, Nov 16, 2003
    #15
  16. There are few disks that can do uncompressed video reliably across a
    single disk without dropping frames. If it is a system that is going to
    be left completely alone, with no other traffic (not connected to a
    network) it might work. It might even work most of the time, but you're
    asking for trouble. The addition of more disks and using a RAID 0
    striping virtually eliminates the problem.

    Cheers,

    C
     
    Chris Mauritz, Nov 16, 2003
    #16
  17. David Lewis

    David Lewis Guest

    Thanks for reply,response in line

    In theory yes.In Practice I was told,rightly or wrongly,to expect an
    approximate 15% performance improvement (not doubling of write speeds)
    Less reliable because if you lose data on either drive you've lost the
    lot.But then again if you lose data on a single drive set -up it's just as
    gone.I guess with 2 drives there is twice the risk? OTOH 2 drives in RAID 0
    improves reliability by lessening chance of dropped frames during video
    capture.
    I know you can do combined RAID 0+1 which would seem to solve the problem
    (my proposed new mobo supports this) but am not sure what downsides this
    would bring

    I am ignorant about this so better go explore. Is it practical for Desktop
    Video home usage?

    Thanks again
     
    David Lewis, Nov 17, 2003
    #17
  18. I would guess that the performance issue would depend rather heavily on
    how much the muxing is implemented in hardware, rather than loading the
    host CPU.
    Yes, but only the failed drive's data is lost -- with striping, you
    lose the failed drive, and its partner. Hence the lesser reliability
    claim.
    That's an improvement of performance, not data security/reliability.
    AFAIK, to do that would either require 4 drives (mirrored setts of
    dstriped pairs), or dividing each drive into two partitions, but that
    doesn't appear to present any performance benefits.

    Once you've gone to 4 drives, you might as well consider 5 (4 data + 1
    parity) in a RAID 5 set, or even 6 drives (4 data, 1 parity, 1 hot
    spare) for automatic recovery from a failed drive.

    Given the very low costs of EIDE and SATA drives these days, and the
    modest cost of a 3ware card (modest in the context of the storage
    capacity and reliability/security issues), it's a no-brainer, from
    where I sit. OTOH, the lower lavels of RAID (0, 1, and 0+1) seem to me
    to be kludgy approaches that hardly deserve to be discussed in the same
    spirit of RAID 5.
     
    William Meyer, Nov 18, 2003
    #18
  19. David Lewis

    David Lewis Guest

    Thanks Bill,will explore further
     
    David Lewis, Nov 18, 2003
    #19
    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.