In the attached patch, a DX11 texture is being generated and shared, and then used in a DX9 renderer. All is well, unless you remove the DX11 preview; then the framerate drops to 2 seconds per frame on my machine.
Add another DX11 renderer, even if it has no input, and the framerate goes back to normal. Hide the DX11 renderer window with Alt-3, back to slowwww.
Weird thing is hiding the Preview window with Alt-3 does NOT slow things down! So the DX11 Preview node is doing some magic that a DX11 Renderer node does not.
SharedSlowdown.v4p (11.3 kB)