You can increase the number of clients to increase the cache throughput. But sometimes if you want to have smaller set of clients and increase throughput, a trick is to use multiple DataCacheFactory instances. The DataCacheFactory instance creates a connection to the servers (e..g if there are 3 servers, it will create 3 connections) and multiplexes all requests from the datacaches on to these connections. So if the put/get volume is very high, these TCP connections might be bottlenecked. So one way is to create multiple DataCacheFactory instances and then use the operations on them.
Warning - dont create too many of these factories as you will end up opening too many connections and waste memory and CPU.