Massive FPS drop while streaming a sub-level

Hi all,

This is my first time posting on the forums as I normally use the answerhub but I thought for this question the forum is a more suitable place. I’m not sure if this is the right section to be asking about level streaming but I couldn’t find anything else.

I am using level streaming in my open-world game as I have a large persistent level. The actual streaming is working fine but every time a sub-level either loads or unloads, the FPS drops from 60 to around 10 for maybe half a second. In many cases this wouldn’t be a huge problem, but my sub-levels aren’t very big so quite a lot are in view at once, meaning if the player wonders around a bit they will get really obvious jerks every now and then. I don’t require the sub-levels to load quickly - is their any way I can trade off loading speed for performance? I wouldn’t mind it taking quite a while to load each one as long as there isn’t an obvious FPS drop. How could I do this?