ID 511573 - Degraded performance on processing live rendering data updates with many Live Render Update Working Sets

Problem summary
The time to process data updates during live rendering degrades proportional to the number of Live Render Update Working Sets selected in the Scene Graph tab.
 
A change in one location can have slow performance in updating the live render when many Live Render Update Working Sets are selected. This appears to be render vendor agnostic.

 
Customer reported version
katana.4.5v3
 
Customer reported platform
n_a_linux
 
Steps to reproduce
 
1) Open the attached liveRenderPerformance_arnold.katana project (a scene with thousands of spheres, a camera, and a light).
2) In the Scene Graph tab, add the /root/world/cam/camera to the Live Render Updates Working Set.
3) Start a Live Render from the RenderSettings node.
4) Wait until the render has converged, which should take about 3 or 4 seconds.
5) In the Viewer tab, change the Look Through camera to /root/world/cam/camera.
6) Move the camera in circles (ALT + LMB click) and notice the live render updates.
7) In the Scene Graph tab, add /root/world/geo and its children to the Live Render Updates Working Set.
8) Move the camera in circles (ALT + LMB click) and notice the live render updates.
 
Expected behavior
The time to process data updates during live rendering should be similar when only having the camera in the Live Render Updates Working Set. The image in the Monitor tab should be updating continually.
 
Actual behavior
The time to process data updates during live rendering is significantly slower when having many Live Render Update Working Sets are selected. The image in the Monitor tab appears to be frozen.
 
Workaround
Unknown
 
Reproduced by support
 
This bug has been reproduced in:
Katana 5.0v3 - CentOS 7
Katana 5.0v1 - CentOS 7
Katana 4.5v3 - CentOS 7
Katana 4.5v1 - CentOS 7
 
Unable to reproduce bug in:
Katana 4.0v8 - CentOS 7
 
Earliest version tested
Katana 4.0v8 - This issue doesn't appear in this version and has regressed