Drop in FPS when closing monitor

[mowgli]

I'm doing some audiovisual recordings using OBS and routing Resolume to it through NDI.
In an attempt to increase the video performance, I closed the monitor in Resolume and to my surprise the FPS of the output dropped considerably.

I would've expected to either increase performance or stay the same, definitely not a drop!
Is there an explanation for this?

Any tips for improving performance when recording to OBS on the same machine that runs Resolume?

[Zoltán]

Probably the OS trying to save power.
Check the settings, in the OS and also the GPU drivers, set to prefer maximum performance.