Laggy engine (Blueprint-window)

like many other people as well, my engine is very “laggy”, when I’m in a new window (for example the blueprint-window). My FPS (as seen in the preview) drops to 10 fps. When the blueprint window isn’t the active one, I have like 120 FPS constant.

System is completly fresh and all drivers are up to date.


  • RAM: 32 GB Ram
  • CPU I7 6700
  • GraphicCard: GTX 1080
  • Windows 10 Pro
  • Board MSI Z170A

I checked the autostart applications, but nothing to spectacular with it.

I attached my dxdiag. Hope you can help me.
[>> DxDiag][1]

Update 1:

I checked other windows as well, even simple forms without interactions results in having those weird issues.

Running the game works fine btw, constant 120fps+

Update 2

It seems that it is somehow related to having 3 screens active. I have 1 Screen via DisplayPort, 1 via HDMI and 1 via DVI - maybe that causes the problem?


After taking a look at the issue described above it sounds like the feature “Use Less CPU when in Background”. If this is the case it, this is working as intended. If you would like to disable this feature you can go into your editor preferences and uncheck it. I have provided a link below to a similar issue for more information. I hope that this information helps.

Link: Huge framerate drop when game window unfocused (4.5/4.6) - Community & Industry Discussion - Epic Developer Community Forums

Make it a great day