The whole point of Cassandra is to run a cluster of servers to handle load at scale with minimal friction instead of having to buy a big single machine or spend all your time/money trying to run a clustered RDBMS. This test doesn't measure the correct thing.
Cassandra's performance scales linearly with the number of nodes though, so per-node performance definitely matters. Probably not 10x, but probably not 1x either.
> 1 DB server (Cassandra / Scylla)
The whole point of Cassandra is to run a cluster of servers to handle load at scale with minimal friction instead of having to buy a big single machine or spend all your time/money trying to run a clustered RDBMS. This test doesn't measure the correct thing.