Significant frame drop while blueprint nodes are being rendered on other monitor.

The nodes in the blueprint editor require a lot of resources to render, causing framerate issues whenever they're being shown. The more that are shown, the worse the framerate issues. While a framerate difference is expected, it shouldn't be so severe for such simple looking elements.

Regression?: No
This also occurs in 4.12.5

1. Create a blueprint project based off the Third Person Template
2. Open the ThirdPersonCharacter blueprint
3. Make the main editor window full screen on one screen and make the blueprint editor full screen on your other (Please note this requires dual monitors to see the full effect)
4. In the main editor window, enter the console command

    stat FPS 

5. In the blueprint editor, drag the graph so that all of the nodes are not visible
6. Observe the fps being shown in the viewport
7. In the blueprint editor, drag and zoom the graph so that all of the nodes are visible
8. Observe the fps being shown in the viewport
   Result: There is a large difference in FPS just for rendering these fairly basic looking nodes (about 30 FPS with a GTX 970 using the setup shown above.) The more nodes in the blueprint, the more FPS is lost.
   Expected: The FPS loss should be there but it shouldn't be this severe.