Two pass execution:

1. first pass only fast nodes are calculated and only to the active
viewer node
2. second pass all nodes to all outputs

Temp disabled highlights because of random crashes.

release/scripts/startup/bl_ui/space_node.py

@@ -233,8 +233,9 @@ class NODE_PT_quality(bpy.types.Panel):
         layout.prop(tree, "edit_quality", text="Edit")
         layout.prop(tree, "chunk_size")
         layout.prop(tree, "use_opencl")
+        layout.prop(tree, "two_pass")
         layout.prop(snode, "show_highlight")
-
+        
 
 class NODE_MT_node_color_presets(Menu):
     """Predefined node color"""