Not too CPU heavy as per my initial impression, should be able to run a few instances without a problem on a decent computer. For some complex presets and when all oscillator sources are utilized, it increases quite a bit though, which is obvious. Pigments 2 has only 2 sources and is apparently more CPU intensive than Equator2.
This is based on quick playing and observations, not proper testing. Hope it helps a bit.
EDIT: Overall, it is in the league of Massive X and Pigments 2 as far as CPU usage is concerned, only a bit less with some not-so-complex presets.
