Stopping RT sometimes takes ages (very very long time). Why?

[GidPDX]

Just wondering why sometimes when I stop RT it takes what feels like ages- several minutes. This isn't always the case with the same scene etc.

Is there anything I can do to improve this? Is this a known issue?

[vladimir.nedev]

Can you reproduce this or does it happen after a long time of randomly tweaking the scene with RT running ?

Is it a complex scene ? How much geometry and textures ?

Greetings,
Vladimir Nedev

[GidPDX]

I can reproduce it. Scene I somewhat complicated, but I find the stopping time changes oddly in that it isn't always taking the longest when the most geo or textures are being rendered.

I'll try and narrow it down a bit and see if I can get you a scene or a video showing what's going on.