Other than streaming, a less obvious single threaded bottleneck would be the LCS compaction, with a rather ugly workaround of using multiple keyspaces as noted

Other than streaming, a less obvious single threaded bottleneck would be the LCS compaction, with a rather ugly workaround of using multiple keyspaces as noted in https://issues.apache.org/jira/browse/CASSANDRA-7949#comment-14223036 https://issues.apache.org/jira/browse/CASSANDRA-7949#comment... With scylla TPC approach, there will be one shard per core, and I think that shall allow more LCS compactions to run in parallel. Theoretically. I have seen the workaround on a very large cassandra cluster. Meanwhile, I never thought to myself that "well, the 200ms p99 with g1gc sure is nice, but my users would be so happy if I can lower it to 20ms". So, if I am scylla, TPC would be my main selling point, coupled with real world examples, but somehow they want to focus on p99.