Has anybody found / done a benchmark that would compare the scalability of a Cassandra cluster vs an ElasticSearch cluster the latter used as a NoSQL database (

Has anybody found / done a benchmark that would compare the scalability of a Cassandra cluster vs an ElasticSearch cluster the latter used as a NoSQL database (with stored fields)? I am interested with 2 kinds of scalability: - volume scalability with single concurrent user: average read / write query times vs stored-data and indexes size vs number of EC2 nodes - concurrency scalability with a fixed size database: average read / write query times vs number of concurrent users vs number of EC2 nodes