I am facing serious framerate drops with build game.

Hi, fellow developers,
My team is developing a game with local VR player and keyboard player playing in the same time. The game have two swindow instance. I konw the framerate can’t be good if we did it this way. But we have about 45 fps in editor mode. Once we build the game, we have only about 21. That’s what really surprised me.
I have ran some tests, lower the graphic won’t fix the game, nor did losing focus cause such a framerate drops.
In this game, we have two swindow instance, I doubt that the game is rendering both VR content and normal content in each window instance even some of the content is not showing in a viewport.
And what made it worse, our designers decided to add more camera in game , to see some stuff from a certain angle. But those graphic didn’t show anything in build game, while it did show content in editor mode.
So, I suspect there is something wrong with slaterender, or slateapplication.

My target is just o restore the fps of the eidor mode for the build game.
I wonder if anyone knows where should I check to solve this problem?



Use the mighty profiler that comes built-in with the Unreal Engine. While running your game inside the editor, open the console (the default is the “^” key), issue the command “stat startfile”, play around for some time, and issue “stat stopfile” again. Now go to Window->Developer Tools->Session Fronted. In the window that pops up, to the top right, you will have four tabs, click the fourth one and load the profile you just created. You will receive a lot of data including where most time is spent. You will be interested in the rendering thread and possibly the game thread. In case you come across CPU stall, you know it it GPU you are bound by (meaning there graphics card has to do so much work your CPU has to even wait for it to finish). Please go ahead and send a few screenshots of the resulting analysis if you wish to have more support.


Ok, sounds nice. I got a little confused by the profiler on the document.

Oh and about the screen shot, sorry for that. I tried to upload some, but only ran into dataerror, don’t know why

The forums have some problem if you try to upload PNG files. Convert it into JPEG and it should work. That is the case for me at least :).

Thanks, I will give it a shot.