Hello, I need help on the Hardware side of Media & Cache in After Effects

None of this will help quite as much as buying more RAM and waiting for it to cache, then playing it back. If it won't play back at a proper speed when cached... thems the breaks and you might want to look at some cheaper, newer alternatives for VFX. It sounds to me you probably want a program that can take advantage of your beefy GPU and isn't a RAM hog, so davinci resolve is a good start- it's free for 4k UHD outputs. I like Nuke, and it has better VFX features than resolve, but it costs a pretty penny.

You could also try turning off hyperthreading or even setting your swap space/page file to better handle overflow from RAM, and making sure your cache is in the drive closest to your CPU, and if only some slots are full, the 2 and 4 slots are usually faster when the others are empty

Since 2019, I've been working from 4TB Flash storage that does 2,400+- MB/s writes and 2,800+- MB/s reads for OS, Applications, and Media Cache and an 8TB external Thunderbolt 3 NVMe SSD that does 1,900 +- writes ands 1,700 MB/s reads four projects, source footage, and renders with no complaints.

Issues come up now and again, but After Effects, Photoshop, Premiere Pro, and Illustrator all run extremely well.

From 2013 to 2018, it was a 1TB Flash storage with 10 GigaBIT SAN.  No complaints then either.

Partitioning SSDs is pretty much a pointless exercise to begin with due to how they work. Other than providing another virtual drive to make things look organized this bears no influence on performance or actual data writing. So in the end it doesn't matter. Only an actual separate SSD will make a difference, but even then you may have to consider how it's hooked up to your PCI bus.

Mylenium