L1 cache (ram cache) only without L2 cache (SSD)

[syednasir]

Any benefits of just setting L1 cache (ram cache) only to cache SSDs and HDDs?

[Jaga]

If you have enough ram for a large L1 cache, you can even cache NVMe drives effectively. I have a 30GB L1 on my 1TB NVMe boot drive which is less than half full, and get great hit rates if I consistently use the same software/game(s).

If the size of your L1 cache is less than 10% of the total data to be cached on the target drive, your hitrates start to suffer (unless you really focus on only one piece of software).