After Effects loves fast SSDs for its cache. In Ae’s preferences, make sure “Enable Disk Cache” is on, choose a folder on your fast SSD for the cache, and set its size as high as you are comfortable.
As you work and preview, Ae will store rendered layers and frames in the disk cache, and then it will read back those stored layers and frames for any operation where reading is faster than re-rendering.
In Preferences > Previews, there’s a “Cache Frames When Idle” setting. If Ae is open and you’re not actively working in it (like, you stop to think, or make coffee, or check email), it can automatically cache frames in your active timeline.
If you’re using a lot of disk-intensive footage in your projects, you could store that on your fast SSD so Ae doesn’t bottleneck on storage on a slower disk.
That said, lots of operations in Ae can be CPU-, GPU-, or RAM-bound, and a fast SSD won’t help you with those.
What are your other system specs?