I have a cache drive in my NAS for reads, thinking about putting a second drive in there so I can have a read/write cache array. It makes a huge difference over just having spinning rust. I’d love an all-flash array, but 36TB of SSD would be very expensive right now.
Note to others reading this: If your main use case is gaming (or anything other than storing/processing buttloads of data), I’d suggest just getting a bigger pcie3 drive instead of a faster pcie4/5 drive. Going with a faster drive won’t be a noticeable difference, but having 2-3x the capacity (for the same price) will help.