Hello everyone,
I would like to give some feedback about my experience with streaming levels regarding performance.For the last couple of days i am trying to figure out why i have this huge performance hit when using them.
For my experiment i opened a backup of my game (without streaming levels) using the same build (17/2/15 master branch) as i use for the current build with the streaming levels.
I loaded my biggest map that exceeds 16000 actors. The results were 120fps for my GPU and ~3% cpu usage that sometimes goes as low as 0.8%
Then i opened my latest game build that has a persistent level (empty) and a few levels as streaming ones.
With my main menu only visible (less than 30 actors) is see 68% cpu usage and my viewport average frame rate is about 85-90 fps.
Now if i enable the exact same level as my first experiment (no streaming levels) i see the exact same cpu usage with the previous example but my GPU drops as low as 20 fps. (!)
Is this normal behaviour?Why streaming levels have such a huge cpu and gpu impact? Sometimes i even see 99% cpu usage making it impossible to work.But even if Unreal stays at the 70% mark the second i open a blueprint ,bye bye development. 
I really need your help with this. Spending 2000$ for a 5960x+mobo+ddr4 is not an option since i do not know if it will actually make any difference because the way i see it the more levels i add the bigger the strain will be for both cpu and gpu. Up until now with my overclocked fx 8350 at 4.7 GHZ and my r290x i could work with unreal and at the same time compile the engine from github in under 25 minutes.
Could this be optimized in any way or it is just how streaming levels work?
Thank you!
EDIT: I forgot to mention one very important thing. If i load only one map (the original level that is now a sub-level) i still have the same performance issues in my project that uses streaming levels. This makes me speculate that the slowdown has nothing to do with the amount of actors that are present in my persistent (as sub levels) level but with something else . All this started the second i added an already created level as a sub level in my new empty persistent level.I would also like to state that my game is a paper2d project if that matters somehow.