Cassandra(with Hadoop) performance with Spark

Hi Folks,
We are running Spark/Hadoop on a different set of nodes than Cassandra. We have 10 Cassandra nodes and multiple spark cores but Cassandra is not running on Hadoop. Performance in fetching data from Cassandra through spark(in yarn client mode) is not very good and bulk data reads from HDFS are faster (6 mins in Cassandra to 2 mins in HDFS). Changing Spark-Cassandra parameters is not helping much also.

Will deploying Hadoop on top of Cassandra solve this issue and majorly impact read performance ?

Thanks & Regards