Frame Time Spikes due to Blackmagic Decklink Quad Hdmi Recorder

On my machine, I found a reproducable problem with Blackmagic Decklink Quad Hdmi Recorder input, resulting in periodic spikes which increase and decrease:

The Decklink is used with two inputs in 25fps. (No input is actually piped into the decklink card, but the behaviour also appears with videoinput)

The spikes appear alongside of a tiny gpu memory increase/decrease.(The two steps refer to the two decklink inputs).

Configuration:

  • Windows Tower
  • Blackmagic Decklink Quad Hdmi Recorder (installed Black Magic Video 14.2.1)
  • RTX4090
  • Intel i914900KF
  • Touchdesigner 2023.12000 running 25fps

Does this also happen on other machine and can this be fixxed?