Dual monitor on mac mini M2 pro gpu/vram use

Hi,

just wondering 'cause I found no satisfying answer...I recently attached a second 27" monitor. to my Mac Mini M² Pro mainly for use with Blender 3d. The first (5k) is connected trough Display port and the second (HD) trough HDMI. Is the memory divided over the 2 monitors, even when the second one is turned off (not in sleep), but connected? I suppose MacOS is clever enough to only gives memory to the second screen when it get the request/signal from the HDMI interface? Like with a tv that switches HDMI ports when it gets a signal on another port.

However, I have the impression that my 5K screen is much smoother when I actually disconnect the HDMI cable. It only takes a few seconds, but still, if not necessary to connect and disconnect the HDMI blindsight, I would prefer just to be able to turn the screen on/off, without losing meory for the main screen (especially when scrolling in huge files in Photoshop (for which i only use the 5k monitor).

Many thanks in advance