Question / Help NDI and 4K: Stuttering


Hey folks -

I need some help and/or suggestions here. Suggestions other than: "stop playing in 4K", please. :-) I've already attached the log files from both the gaming rig and the streaming rig. Their names should give them away.

The Problem:
Gaming PC with 2 Titan X Pascal GPUs that are overclocked +200MHz (and +500MHz memory). When I'm playing Rainbow Six Siege in 4K, there are moments when the load on both GPUs bumps into 100%. When that happens, the resulting NDI video on the streaming rig stutters. Which means the stream viewers also see stuttering.

I'm not scaling the video down on either machine. The canvas on both OBS processes is 4K/60. And the outgoing stream to YouTube is also 4K/60. With games that run the Frostbite engine (eg: Battlefield 1, Battlefield 4, etc), SLI'd 4K is easy and efficient. I can hold my 140FPS soft-limit without terrible load on the machine. But Siege's Anvil engine is very inefficient, and it kicks the crap out of both GPUs.

Is there something I can do, at all, to prevent the stuttering with the GPUs hit 100%? I don't see or feel that in game. It happily maintains its 140FPS. But the preview window on the streaming rig clearly shows stuttering and skipping, and that's transmitted to YT unfortunately. I'm guessing I'm SOL, but I figured I'd ask.

To cover all the bases: Yes, I have the Elgato 4K60 Pro card in my streaming rig (you'll see that in the OBS logs). No, I shouldn't use it. The reason is that screen cloning also beats the snot out of my GPU, which causes noticeable frame dumps in-game. While Titans are pretty damned powerful, asking the primary to play at 4K and clone at 4K is a bit much. That's why I'm trying NDI again.


  • OBS-logs-gaming.txt
    13.4 KB · Views: 20
  • OBS-logs-streaming.txt
    19.1 KB · Views: 19