Single vs multi core processor for CAD

Hi im looking to buy a new computer a Custom PC and i wonder if i should go with a 8 core Intel (9900k) processor with turbo up 5ghz and 16 cache or a Ryzen threadripper (1920x) with 12 cores 38 cache and turbo up to 4ghz?

What is best for CAD? Heard alot of software is only using one core at at time! Ive had the most problem coping with patterns and multiple extrudes. And how big part is the graphic Cards effect was thinking of going with a 1660ti

Programs i will use most is
Fusion 360
And in the future maybe some marvelous designer and cinema 4D

You can’t BUY a single-core processor anymore, the question is how many are useful. “Content creation” tools are mostly not even theoretically possible to parallelize, certain aspects of certain operations are, very few tools in Rhino are multithreaded.

Unless you’re doing CPU rendering you aren’t going to get much use out of 12 cores, no, but don’t get the 9900K, Intel is right now kind of obsolete, without slashing prices they have nothing you can buy now to compare to the Ryzen 3000 series, it’s only a matter of do you get a Ryzen now or wait for the next-gen Threadripper.

Get as much video card as you can afford, basically.