I'm working on an archiviz scene, multiflat house with a little garden. In the garden, I'm adding a small pool, created in a separate file and then imported in this. During the pool creation, I played a little to set up caustics and I got a pretty good result, done in 5 minutes render in fullhd.
Now, in this scene, if caustics are activated, render time, from 10/12 minutes, render time goes up to 20-40 hours.
Is there any known bug by a chance?