[lkml]   [2002]   [Jan]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [2.4.17/18pre] VM and swap - it's really unusable
    Rob Landley wrote:

    > And a sound card with only 1mS of buffer in it is definitely not useable on
    > windoze, the minimum buffer in the cheapest $12 PCI sound card I've seen is
    > about 1/4 second (250ms). (Is this what you mean by "hardware fun"?) Even
    > if the app was taking half that, it's still a > 100ms big gap where the OS
    > leaves it hanging before you get a dropout. (Okay, some of that's watermark
    > policy, not sending more data to the card until half the buffer is
    > exhausted...) What sound output device DOESN'T have this much cache?

    Imagine taking an input, doing dsp-type calculations on it, and sending it back
    as output. Now...imagine doing it in realtime with the output being fed back to
    a monitor speaker. Think about what would happen if the output of the monitor
    speaker is 1/4 second behind the input at the mike. Now do you see the
    problem? A few ms of delay might be okay. A few hundred ms definately is not.

    > Now VIDEO is a slightly more interesting problem. (Or synchronizing audio
    > and video by sending really tiny chunks of audio.) There's no hardware
    > buffer there to cover our latency sins. Then again, dropping frames is
    > considered normal in the video world, isn't it? :)

    If I'm trying to watch a DVD on my computer, and assuming my CPU is powerful
    enough to decode in realtime, then I want the DVD player to take
    priority--dropping frames just because I'm starting up netscape is not


    Chris Friesen | MailStop: 043/33/F10
    Nortel Networks | work: (613) 765-0557
    3500 Carling Avenue | fax: (613) 765-2986
    Nepean, ON K2H 8E9 Canada | email:
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 13:15    [W:0.025 / U:69.216 seconds]
    ©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site