For any SQL/NoSQL system, the more RAM, the better. They need as much RAM as possible to cache the data.
If you observed cassandra consumes a lot of RAM even with small dataset, you should tune the GC settings. Besides it, JVM itself consumes a lot of RAM.
If you observed cassandra consumes a lot of RAM even with small dataset, you should tune the GC settings. Besides it, JVM itself consumes a lot of RAM.