The 4.5 update helped a little but S1 still isn't multicore optimized. Whereas DAW's like Logic spread out the workload of a single channel onto multiple cores. S1 only uses multiple cores for multiple channels, meaning that having multiple plugins on a single channel can quickly cause dropouts. This is especially concerning for many producers who produce with a temporary mastering chain on the mix bus, rendering this workflow nearly impossible.
Please add multicore support for single channels.