Artistic artifacts in orthographic render view

Hi,
i just changed my graphics card to GTX660Ti and i found out that i get weird artifacts when rendering in view mode with ortographic camera using GPU.
Example http://i.imgur.com/sUrArKP.png?1

Should i be worried about the card or some Blender settings?

Everything looks fine in final renders(ortho and persp.) or in perspective render view.

There are known issues with artifacts in orthographic view
You could try adjusting the clip start/end distances https://developer.blender.org/T36281