intel experience


    Dec 01 2006 | 10:05 pm
    hi!
    i have just made a strange experience working on an intel mini mac we
    use for an installation.
    i was planning to run the machine without a display connected as its
    output is only sound and dmx with another part of the patch doing
    jitter video processing of a live camera feed.
    in such a situation i use a VNC server to be able to operate the
    machine remotely.
    this works flawlessly when an actual screen is connected to the mini
    mac.
    if i unplug the screen, though, and reboot without a display the
    jitter performance drops from 30 fps to 5 fps.
    now, if i do the same to a PPC mini mac the same thing happens, but
    not quite as bad.
    the frame rate drops from 11 fps to 7.5 fps, so that in the end the
    PPC outruns the intel machine (!) which is actually 3 times as fast.
    would anyone know a way to explain this?
    as far as i understand it the intel machine does not have any
    dedicated video ram anymore, but uses a part of the computers memory.
    presumably the size of memory changes depending on the size of the
    display and without an actual screen there, it could be very small.
    could i fool the intel machine that there really is a nice 20 inch
    screen there somewhere..?
    any pointers would be appreciated!
    many thanks
    hiaz