New Nvidia Surround MultiMonitor is nice, but

Having some weird framerate experiences. I’m running vvvv 31.2 x64 with a Nvidia GTX 760. Nvidia finally enabled the 2-Display-Span-mode in Surround in their latest driver (and other configurations, too) which is really nice, since ATI had that option long time ago already.

So my setup is two Monitors Span (3200x1200) plus one 1680x1050
But… starting a patch with the renderer on the span-setup gives me 23FPS (Fullscreen or Windowed does not make a difference)
I have to force the Renderer in 1024x768-Fullscreen, disconnect the Layers and reconnect, then switch to 3200x1200 (As Desktop) which gives me nice freaking 60+FPS on the same patch in 3200x1200.

I’m using the MRE by dottore & co with SSAO, Shadows, Lightning,…, maybe this is related to the MRE-Engine but on a single monitor changing Output-Resolution and content-reset my best performance is 47FPS. So it has to be something related to the way of vvvv using the graphics card’s buffer or something.

maybe someone knows a little bit more details.
For everyone else: The new Nvidia Surround is nice! :)