"ScyllaDB also handles complex query processing in the same engine. RonDB does all complex query processing in MySQL in a separate program." — i.e., as soon as things might get a bit hairy, RonDB punts it off-system. While a clever way to keep performance numbers high, you'd have to also then analyze the MySQL latencies and throughputs to get an overall view of complete system performance.
It's a clever dodge, but it's not a magical way to eliminate the need for those pesky CPU cycle times.
