I was reading an article @ http://www.acunu.com/products/choosing-cassandra/ and it mentions cassandra cannot benefit from more than 8GB allocated to JVM heap.  Is this true?  Are these cassandra installations with larger heap sizes? We are planning to have a cluster of 6 nodes with each node running with about 100 GB or so RAM. Will this be a problem? 


from http://www.acunu.com/products/choosing-cassandra/

Memory Ceiling

Cassandra typically cannot benefit from more than 8GB of RAM allocated to the Java heap, imposing a hard limit on data size. Taking advantage of big servers with lots of memory or many disks is no problem for Acunu. Thereʼs no memory ceiling for Acunu and as a result, no data ceiling either. Need to use larger servers? Go ahead.