Proxies in Blender?

Hi,
I was wondering if there are proxies in Blender Cycles.
I would like to render a model with a few millions of polygons, but the viewport performance slows down a little.
So, in renders like V-ray you could create a proxy, to load heavy weight meshes, these look some what raw in the view-port, but fine in the final render.

Can we do that in Blender Cycles?
Many thanks

In blender, a “proxy” means something quite different.

But to answer your question, my rendered models are smoothed by a sub-surfacing algorithm. The smoothing can be toggled for the viewport and renders. You can also change the degree of smoothing (i.e. the relative number of subdivisions) for either the viewport or render.