What are some rough performance limits (read/s, write/s) for a single database server (no master-slave architecture), assuming storage on disk? How many read/s, write/s, depending on the kind of disk? (SSD vs non-SSD) , assuming simple operations (select one row by primary key, update one row, correctly indexed). I assume this limit is dependent on disk seek/write.

EDIT: My question is more about getting rough metrics of the number of operations a database supports: to be able to know for example, if a new feature triggering 300 inserts/s can be supported without scaling out with additional servers.