Is it possble to create sharp procedural voronoi texture in cycles?
,how it is now 
,how it need to be
,How would be perfect)
Have you tried to apply a color ramp to first image?. I think that tweaking that color ramp you will get a result similar to the second image.
Not at the moment. A voronoi crackle procedural texture is very high on my wish list. Better to bring in a raster texture than to use a very large nodetree to fake it.
there is an OSL to do voronoi crackle!
did you try it
but not certain it can work with ramp !
happy bl