It seems that when working in any project on a Windows 10 machine, there is a gradual rise in frames per second and a consistent drop in performance.
The user reporting this issue claims his frame rate drops after he has toggled fullscreen, and eventually needs to restart the editor to return to the expected framerate.
When testing this issue on the Win 10 machine we have here, I noticed this was not the case on my end. After opening a default template project (FPS Template or TP Template) and toggling fullscreen, when observing the 'Stat UnitGraph' the stats all begin to gradually rise. This produces a very low performing In editor experience.
I attempted to test these exact same project on my Windows 7 machine and did not experience any sort of performance issues. I also got Matthew Clark to test this issue on a different Win 10 machine, but he did not see what I am reporting.
Tested in Binary 4.9.2 - 2707645 - Issue occurs
Tested in Binary 4.10 - 2758231 - Issue occurs
1. Create First Person Template Blueprint Project.
2. Type 'Stat UnitGraph' in console command window.
3. Press PIE
4. Toggle fullscreen on and off by pressing F11.
5. Exit PIE
6. Let the viewport sit with the stat graph still visible.
Outcome The lines on the Stat graph should slowly start to rise.
Expected The performance while in editor is at the same as when the project was initially opened.
Head over to the existing AnswerHub thread and let us know what's up.