Rendering with Iray
To start a render using Iray, enable Iray rendering with the 
button. Rendering will begin in the active viewport.
To increase interactivity, you may choose to keep the Patchwork 3D rendering in the active viewport and to send the Iray rendering to a remote window. To do so:
Open the Iray settings editor
Enable the rendering in a remote window with the button
If the remote window is hidden, show it by clicking on the button
During refinement, the number of passes and the current rendering time are displayed at the top of the Iray settings editor and at the top of the remote Iray rendering window, if the remote window is enabled.
A message is also displayed in the Patchwork 3D status bar when refinement has finished.