So apparently it is claimed on Immersive Engineering's issue tab that it it a Rubidium 0.5.5 issue.
It's like cubic chunks got splattered all over the place.
There are screenshots both on their issues tab as well as on this one, a few publications back: #441
Btw, I am aware that it can be "fixed" by adding mixin.features.chunk_rendering=false to config/rubidium-mixins.properties, but it creates weird animation glitches (water, kelp for example), makes trees have what seems to be -∞ mipmaps and also decreases fps.

DIS BETTAH BE FIXED [insert angry anvil sound ^^]

same?

or is this something else

The same problem, only in my case adding mixin.features.chunk_rendering=false greatly reduces fps and causes freezes

Update Rubidium