Hello everyone,
This is a continuation of this forum post: Streaming levels Performance questions. - Feedback & Requests - Epic Developer Community Forums.
A little more information on this. As the pictures show it makes no logical sense (to me at least) that performance will decrease by x30 times because i added to my persistent level 3 times the actors of a single level.You simply cannot go from 3% cpu usage to 70/80 or even 99% with something like this.Another strange thing is why the GPU performance is affected as well. Any help will be greatly appreciated since i cannot work anymore under these circumstances .It takes forever to do the simplest of tasks.
Thank you.
Hi ,
Does this occur in a blank project with no additional content or is it limited to a specific project?
I am afraid it is happening only in my project.I read that cleaning up re directories might fix this problem but unfortunately it didn’t. Any ideas or suggestions on how to cure this?
Are you using any bsp’s in your level? If so changing these to static meshes will help reduce the amount of resources being used. Additionally how many draw calls are being made in your game? If you have a lot of complex textures you may be getting a lot of draw calls, which would absorb resources as well.
My game is a paper2d only game and i have 0 bsp’s. In matter of fact i only use sprites for everything. Up until 4 days ago my game was running at >100fps as a “new editor window” with unreal minimized or about 70fps with a blueprint in debugging mode.Now it runs at a max of 25fps(!) in the first scenario and less than 15 in the second.My cpu usage as you already know spiked to ridiculous numbers.It is the EXACT same game but i just added my levels under an empty persistent level. That for some strange reason triggered something that causes all the above.
At first i thought it had to do with either how streaming levels behave or the fact that i had many actors but now i am convinced that this it is not the case.It is illogical to add 3 times the amount of actors into a streaming level(than you previously had with only one level) and see a 3000% performance drop,
After some searching in the answerhub i saw similar cases or random performance drops and i am wondering what is causing them.
The good news is not having those two things rules out the easiest problems and their solutions. Do you have a copy of the project that you wouldn’t mind sharing? I know Ben here at the office has a copy, however he won’t be back into the office until Monday so if you have a copy I’d be more than happy to take a look and see what might be occurring.
I have (sort of) good news. I narrowed it down and it has nothing to do with anything regarding the amount of actors,streaming levels or whatever. It has to do with the fact that unreal does not use my GPU and (i assume) it offloads all the calculations to my CPU and that is the reason for the slowdown.
Lets take it from the start. I was (still am!) so stressed out with me not being able to work all these days that i decided when i suspected that it was a GPU (couldn’t possibly imagine then that it was not hardware but software) malfunction to go and buy an ASUS GTX980 STRIX.
I formatted my system, re-installed win 8.1 installed the new card and when i opened for the first time unreal, BOOM! 120FPS on the editor and 120FPS on the standalone window at the same time! I go to bed since it was really late ready to enjoy my victory (apart from the fact that i am 700$ poorer lol ) over my sleep.
When i open up Unreal again this morning i see that terrible cpu and GPU(i assumed) meltdown .When i stopped swearing i had an epiphany to open up the GPU monitor. And guess what ? :
As you can see my cpu is melting and my gpu is not even bothering.On the second picture you can see that it never goes beyond 15% .
What the heck is going on? This is not driver specific since it does the exact same thing with 2 different gpu brands. I tried to play around with nvidia settings (maximum performance etc) but with no success. The second i fire up a benchmark ( 3d mark, passmark etc) everything goes to 100% and my score ratings are superb.
Have you ever heard something like this before? Another thing that needs our attention are the newly created seams (you can see them at the second picture) between tiles. But i believe they are caused by the fact that the GPU does not render anything as its supposed to do.
Heeelp!
I pinpointed what is causing this!
The slowdown is caused by my movies!!
My movies are all WMV, and they are located in " Content/Movies" inside my content browser .I then make a media texture and from there i create a texture material that i either use inside a UMG or as a material for a actor.
The (details) source for the movie is the default “File or URL” and the stream mode is from “URL”. Each of my movies original location is located inside my dropbox folder.For some strange reason when i created my streaming levels this started to create the slowdown! If i go to my dropbox and change the folder name (that contains all my videos) to something else and unreal cannot find the path for them everything goes back to normal. WTF???
The reason i told you earlier that when i first opened my game with the new graphics card everything was ok , it was because i hadn’t installed dropbox yet and i had accidentally found the cure for it.Before i went to bed i left it open to download everything and in the morning when unreal found my videos she started behaving badly again.
You can see in my second picture that the video is missing. My CPU is happy again!
Now i sometimes have 120fps both in the editor and in my preview and sometimes i have about 75 (as seen in the picture). It is a HUGE improvement but the question is why on earth would my videos file path cause something like this when i started using stream levels? Why my GPU usage is still so low and why do i have seams in my tiles?
Questions , questions questions… 
If you change the location of the movies from dropbox to another location, do you still see the same FPS drop? It could be the fact that it is pulling from a dedicated FTP service as opposed to directly from your HDD that the framerate drops so low.
I will try it when i get back home but i highly doubt that this is the problem since these videos are present in my project for a little more than a month now and the files reference locations are in my ssd. Also if i open up one of my backups from the day before i started using streaming levels everything works perfectly fine. It must be a weird combination of things that is causing this but to be 100% certain i will post back as soon as i try your suggestion.
I just moved all of my videos locally to my SSD, set up one by one all my videos file references to the new location and i still see exactly the same terrible performance loss. The second i changed the folder name to something else and Unreal lost their references everything went back to super smooth.
So there is a huge bug hidden in there .
Could you send me one of the movies causing this fps drop? I will try to run it in a blank project at the office and see if I can reproduce the same error. Any reproduction steps you could provide that would allow me to recreate this on my end would be beneficial to attempting to find the root cause of the error.
OK, let me see what i can do about it
Hi ,
We have not heard from you in a few days. I am marking this thread as answered for tracking purposes. If you are still experiencing this error, please comment with the requested information. Thank you!
