Cubase Pro 9 Struggling under controller data


I’m running CB Pro 9.0.4 on OS X 10.12.5 and have found that it struggles when there’s a certain amount of CC data. In this instance, i’m doing a small quartet-ish mock up and am using 3 or 4 CC’s on each of the kontakt string tracks for expression, dynamics and vibrato control etc. Even with the lowest buffer setting of 2048, CB spits and struggles to deal with the CC data and the CPU monitor is hitting just below 50%. I’ve tried different options in the audio control panel like, ASIO guard off/on, multi threading off/on etc. but same result. It’s not RAM related as there’s plenty spare so am not sure what’s occurring.

Any thoughts and or ideas?