How to fix normal shading in Cycles?

[Zot]

Hello, how to fix those sharp edges in Cycles render? Please help.
It’s just a smoothed ico sphere.

[omgold]

It’s called terminator artifacts. See .e.g. my answer here:

Cycles Rendering Artifacts

I have searched but found no solution. I’m getting artifacts in cycles render, and in viewport when I use the Rendered mode. I managed to eliminate them when I used subdivision modifier, but the moment I Apply the modifier, the artifacts are back again. Anyway, I don’t want to have to use subdivision every time, sometimes my mesh is already the way it’s supposed to be. Here are quick renders for comparison: low resolution, no modifier. [Pinky01] With Subdivision modifier on [Pinky02] After c…