NDI Computational Overhead & Limits vs HDMI & Friends?
  • CaseyJScalf
    member
    Posts: 49
    Joined: Sat Nov 08, 2014 10:15 am

    NDI Computational Overhead & Limits vs HDMI & Friends?

    by CaseyJScalf » Tue Jun 02, 2020 12:10 am

    Getting really pumped on being stoked about the NDI protocol from NewTek.

    From what I gather Syphon and Spout are still the most efficient way to send video between applications on the same computer.

    But! I am curious about what kind of limits there are for sending video over the network using NDI?

    For instance, I love maxing out computers to see how many video outs I can reliably get. You know, multiple graphics cards, weird USB-C -> HDMI Dongles, and of course the famous Matrox TripleHead2Go's.

    But! What if I could best my current records (x7 1080p@30 videos outs from a NUC Hades Canyon - running at 30 FPS with 3 layers clean BTW!!) and get say 10, or above, by using the NDI protocol? It seems like there is about 100 Mbps of overhead from each HDMI stream in NDI. So on a 1 Gb network and card we should be able to connect to at least x9 1080p@30 screens/projectors/etc right?

    Now to the real meat of it... Without buying all of the gear is it possible to test this? Say send NDI signals but not actually have any of those decoders downstream? To test out the limits right? Can your GPU/CPU handles more video outs, more efficiently, than just native HDMI & DisplayPort IO by themselves?

    Wow! If so that would be revolutionary! Finally a simpler cable that can do a lot more!

    Just checking in... thank you for keeping this tool on the new new.
  • mad-matt
    garageCube team
    Posts: 986
    Joined: Mon Sep 09, 2013 5:50 pm

    Re: NDI Computational Overhead & Limits vs HDMI & Friends?

    by mad-matt » Fri Jun 05, 2020 10:05 am

    I know some people are using it intensively in a club in Geneva. They have a powerful PC that gathers NDI from artists laptop and use MadMapper to map all this content to a bunch of video projectors.
    The problem is encoding. NDI will use your GPU to encode H264 streams. It does it fine, but encore 10x fullHD, I'm not sure. Since MadMapper you can force the engine to run at 30FPS, so 10 1080p30 would be equivalent to encoding 5x 1080p60 streams. With a good GPU I think that could be ok.
    To test, I would suggest installing MadMapper on another computer, even demo version, and display all the streams you get from the other machine. You could also use several instances of NDI Monitor.
    Let us know your findings !
  • CaseyJScalf
    member
    Posts: 49
    Joined: Sat Nov 08, 2014 10:15 am

    Re: NDI Computational Overhead & Limits vs HDMI & Friends?

    by CaseyJScalf » Mon Jun 08, 2020 9:15 pm

    Thank you for taking the time to reply.

    That is nice to hear that a club is using it to great success.

    I will indeed proceed with some tests sending video from one computer to another over Ethernet..... How wonderful it is that we can even do that!

Who is online

Users browsing this forum: No registered users and 1 guest