Handy adapter allows normal performance on a "headless" Mac

  • Dear All,

    Whilst investigating a bug last night, I was using a mini Mac via screen sharing. The performance of Isadora was very poor... and then I learned about the problems with "headless" Macs, i.e., running a program on a computer with no display attached.
    On Mac OS X, when there is no monitor attached, all of the OpenGL calls revert to a software emulation, making things run very slowly. Of course, given that Isadora's primary purpose is to do video, this would seem like a "useless" situation -- i.e., running a Isadora on a computer that has no monitor and no video projector connected. But, who knows... you all come up with some strange setups sometimes. ;-)
    Anyway, the solution is to "fool" the computer into thinking there is a display. By using one of the adapters below, the computer thinks there is a monitor or video projector, loads the normal (fast) OpenGL drivers, and performance returns to normal.
    Below are some links to a "DIY" (do it yourself) and a pre-built solution.
    Perhaps there are other solutions out there. But these were the first to come up in Google.
    All the Best,
    @fubbi: perhaps this would have helped you in Shang-hai?

  • Ha! I was going to use Mini in one of my sound objects processing sensors data from Arduino into MIDI and sound samples with Isadora. Your discovery comes just in time. Thanks!

    I wonder if this issue is present on older Intel MacMinis with DVI port as well?
  • Izzy Guru


    Been experimenting with a live feed and masking your face into portraits for the art gallery here at work.... I was thinking of running it headless! (was just going to use VNC to get into it)
    So this could be handy! Thanks.

  • You guys are "misfortune" tellers! Amazing!

  • This is great!

    I use Izzy a lot in sound installations… although, so far, I used an iMac.

  • WOW

    this is kinda major 
    this explains many many problems...  As I often work headless
    do you have any pointers to other documentation on this? (apple dev, etc)
    thanks for the heads up

  • @mark : we did look into this a lot b4 shanghai but in the end we needed "heads" for the individual machines anyway so it was no issue.
    Most of the documentation I have found on this in the past has been in server forums where the issue is getting the most out of the GPU in server racks where no monitors are attached. Do a search for "headless server" to get into some seriously nerdy stuff.
    you can also get the dummies on ebay, just search for DVI EDID emulator or VGA emulator