When working with more than 2 outputs from ProPresenter 7 (such as two auditorium outputs, a stage display, and a hallway feed), we recommend using VIDEO-based outputs rather than using GRAPHICS outputs.
As a primer…
GRAPHICS outputs are seen by your computer operating system as desktop displays. They are wired directly to the graphics card and have to be configured individually by the operating system. Your computer's desktop will be shown on graphics outputs.
VIDEO outputs (as far as ProPresenter is concerned) are Blackmagic Design DeckLink or UltraStudio devices that have SDI or HDMI outputs. These devices do NOT show up in the operating system as separate displays, but are addressable by ProPresenter. These outputs are SMPTE (television broadcast) standard, rather than computer standard.
All content in ProPresenter is drawn and composited in the computer's graphics card (or GPU). When using VIDEO outputs, the data for each output is copied from the GPU, encapsulated as a video stream by ProPresenter, and sent out the video outputs. As such, when using a lot of outputs, you need to have a dedicated GPU, regardless of whether those outputs are from the graphics card directly or through the video device. These video devices, however, are dedicated ProPresenter outputs and are not encumbered by the operating system the way graphics outputs are.
You can achieve up to four outputs with the Blackmagic DeckLink Duo2 card, and up to eight outputs with the DeckLink Quad2. Any one of the 4/8 ports respectively of these cards can alternatively be used as a video input for live camera feeds. These are both PCIe cards that can be installed on any desktop computer with appropriate slots. Macs without slots can use these cards by using external chassis that are connected with Thunderbolt 3. These are all available in the "Broadcast Video" section of our online store.