larger cpu core or more cores better?

Szalam  wrote Was it Puget Sound or something like that? I've heard lots of good things about them. Especially for folks building multi-GPU rigs for using Octane or Cycles4D in Cinema 4D. They seem like a very competent company with great customer service.

Yes Puget Systems. They have graphs and stuff with comparisons. I was a bit confused about why in their recommended hardware they seemed to be saying the i7 6850K was mostly best (eg. in 2D anim), except for some tasks, but following the link that they said the i7 6700K 4.0-4.2 Ghz was better (but just now it seems like they don't recommend the 6700K because it doesn't support more than 64 GB RAM) (they also recommend the Core i7 6900K - even though their graph said it was slower for 2D anim.).

Since the 6700K is what the OP has - and if more RAM could help at all (eg. for 4K stuff - I don't know if the comps are 4K or just the monitor) I assume the processor would need to be changed (based on the above website). While using something like a 6850K instead might be slightly slower (processor-wise) - it should allow a lot more RAM so more could be cached - which could speed various things up.

andrews90790780  wrote any idea why the multithread rendering was removed?

Yes.

Long story.

The AE team asked in a blog post if we, the users, would prefer them to keep on trying to add features to AE or to take a bit of a break from that and work on simply improving AE's speed in interactivity and rendering.

Overwhelmingly, we said, "SPEED!"

So, the AE team set to work tearing apart AE's code and rebuilding the architecture almost from scratch in order to modernize the decades old code.

They debuted parts of this new architecture in CC 2015. It was much buggier than anybody would have liked, but there was a noticeable change in how AE worked. You could now keep on working with AE while the renderer was chugging away on something. This was a HUGE improvement in interactivity. Now, in CC 2017 (the 14.1 update), all of the big bugs have been squashed and AE's new architecture is more in place. It runs smoothly and stable for many/most folks and has gotten faster and faster.

So, we have much faster interactivity. However, they are not as far along on getting a new renderer in place to make rendering faster.

Downside to the rewrite is that multiprocessing was not compatible with the new architecture. Multiprocessing, for those who might not be aware, wasn't a very good solution. It was an old kludge to make the single-threaded After Effects use multiple cores. What it would do is spin up several After Effects processes in the background to render a bunch of frames. Now, it was pretty clever, but it had a number of bugs. For example, shading in the popular third-party plugin Trapcode Particular would sometimes go all flickery. Sometimes renders would fail or never even start. Some expressions weren't compatible with multiprocessing, so it would be disabled. Same with some effects (third party and native).

So, old AE was single-threaded, but kinda faked it sometimes. The new AE is genuinely using multiple threads (the UI and renderer run on different threads) which AE has never done before. And, the new C4D renderer (for generating 3d geometry natively in AE) is also a fully multithreaded renderer. The problem is that AE's main renderer isn't multithreaded yet.

Now, that's not to say that the new version of AE is always slower. With more and more effects being GPU-accelerated (which the old versions of AE never had) and AE being more efficient in other things, some projects will render quicker on the newer version. Some will render quicker on older versions.

If you find yourself more often in situations where the older version renders significantly faster, I recommend working in the new version (faster interactivity) and then save it back to version 13 to render in CC 2014 (the last version with the old architecture).

For what it's worth, I haven't opened CC 2014 in my freelance studio in months.

Does that help?