During the holidays, OctaneRender for Carrara 3.0.0.1 Beta version was released, the GPU rendering plugin that is fully integrated into Carrara.
The beta is free for those that have a license for the 2.x version.
There is also a free demo if you have not tried out OctaneRender for Carrara here:
https://home.otoy.com/render/octane-render/demo/

The beta 3.0.5.03.32 Carrara plugin thread at the Octane forums, started 2016-10-16, contains several bug fixes and new features, full release log available in the forum thread:
https://render.otoy.com/forum/viewtopic.php?f=79&t=56881

More info about the upcoming Octane V3 release:
https://home.otoy.com/otoy-unveils-octanerender-3-worlds-best-gpu-renderer/
https://render.otoy.com/forum/viewtopic.php?f=33&t=51681
https://render.otoy.com/forum/viewtopic.php?f=33&t=51679

The main thread about the OctaneRender Carrara plugin:
https://render.otoy.com/forum/viewtopic.php?f=7&t=41907

At the DAZ3D forums, there is some more info and a few renders:
http://www.daz3d.com/forums/discussion/45564/octane-render-for-carrara-or4c-public-beta-now-released/p1