Additional windows drop their FPS while in focus instead of out of focus

EDIT: I made an error, the bug is simply when the main UE4 window is not in focus all windows have FPS throttled. This also occurs when playing the packaged game.

With this new engine, somewhere around release preview 5, additional windows would lose frame rate when in focus, and they would regain their normal frame rate when out of focus. It has been inversed.

Now when I’m trying to even use the blueprint graph the FPS is horrible. To preview an animation I have to start it then drop focus from the window for it to playback properly.

In case it could be related to my GPU or CPU… :
GPU: Asus strix 980TI
CPU: i5820k 6-core i7 @ 4.3ghz

This just became pretty urgent. Packaged games have the same issue. When I tab out the FPS begins to increment over time, like each second the FPS rises by around ~3, using stat fps shows it going up like a timer… :confused:

Hi ,

  • Does this occur in a clean, blank project with no additional content or is it limited to one project?
  • What steps can I take to reproduce this on my end?
  • Are you in a packaged game or in PIE/standalone?

These are the steps I will take for the first two questions

I do these after turning on my computer, nothing else was running.

  1. From the 4.12.2 launcher engine (not source engine) make a new project, C++ Basic Code, Desktop/Console, Maximum Quality, No Starter Content, the launcher then automatically opens both VS2015 and the UE4 editor

  2. Wait for visual to do it’s initial parse so it’s not using resources (CPU in particular), confirm via task manager that resources are all free (low cpu/mem/hdd consumption)

  3. I press ` and type ‘stat fps’ to bring up the fps stat. UE4 FPS wont go above 24 FPS. The issue is different from before. I make a new blueprint based on “Character” and open it. The FPS on the UE4 main window goes up to 120FPS. I click on the UE4 main window and it drops to 4 fps and over the period of ~2 seconds climbs back to it’s previous cap of 24FPS. I click back on the blueprint window and it shoots back to 120FPS. When I’m typing on Chrome on another monitor, it is near 80FPS.

The answer to question #1 is yes it occurs on any and all projects regardless of whether they’re blank. The answer to question #2 is above. The answer to question #3 is BOTH, this happens in UE4 editor as well as in packaged games however it does not require me to PIE. My friend tried the packaged game on his own computer and did not encounter this issue. My suspicion is the error is related to some certain hardware and an update that happened during 4.12.

The project I was working on yesterday only had proper FPS when the main window was in focus, this new one only has proper FPS when the main window is NOT in focus.

Edit → Editor Preferences → Miscellaneous → Use Less CPU when in Background UNCHECKED does not help.

The hardware on my computer is all high-end and would fall in the minority for usage, I will include a dxdiag.txt - I’ll remove this in a few days.

For now you can close this. I’ll post again if necessary.

I noticed the issue was only occurring on my rog swift monitor running at 165hz, I changed the refresh rate to 120hz then back to 165hz and the problem went away.