Recommended PC for Quartus Prime Pro compilations

Faster cores are better than more cores. The compilation will spend a lot of time in a single core. This will be the single biggest factor (after ram requirements) that will affect build speed. With more cores, you can also run more builds in parallel (ensure you have enough ram)

More cache is better

I also think an SSD can improve times a bit, as there are large databases that may get written to disk, so you may save a bit of time here, but it is mostly going in and out of ram.