Are Adaptive Subdivisions/Displacement broken right now?

I tried to use adaptive subdivisions, dicing is not working, or it seems so, I did not file a bug yet because my build is not from today, but I have a deadline, so I don’t want to change to another build, but I wanted to share this just in case it’s a known problem.

A plane with some displacement, normal Subdiv modifier (not as detailed): 700Mb or Ram
A plane with adaptive subdivisions, dicing at 2 pixels: 5.5Gb or RAM
A plane with adaptive subdivisions, dicing at 16 pixels: 5.5Gb or RAM, exact same visual result, no matter if I change the dicing on the subdiv modifier or in the cycles settings, RAM use is totally absurd and it does not react.

This question may be for @sergey or @brecht probably.


There is a bug where Blender will still do its own subdivision before Cycles. Seeing the subdivision levels to 0 can work around that.

mmm I think it’s not the same bug, the problem is that the result don’t change no matter how much dicing I configure in the modifier or in the render settings, the result is always 5Gb no matter what.

Also setting subdivs at 0 will interfere with other models that don’t use adaptive subdiv but rather normal subdiv.

I’ll check the problem again anyways and publish a bug if I find that it’s not the same problem.