The key with big mixes is more cores / threads Generally, a daw will attempt to stick a centralized process on to a separate core / thread. So generally, each track will be on a separate core / thread, until they're processed through a common bus that contains a plugin. Then they all get stuck on the same core / thread. So on and so forth. This is why you never stick plugins on master until midtown.

When you're running multiple layers of guitars, drums, vox, etc each with their own plugin chain, you need a lot of power and speed.

It's not uncommon for me to run two instances of superior drummer three with the tracks broken out. 40+ tracks just for the kits that feed into 10 busses. That feed into four busses. That feed into a final drum bus at midtown. And that's just the drums. Don't ask me about a guitar chain.

I can easily choke 36 threads if I don't set the chains up right. Even then I have to be careful prior to mixdown.