Request to help us to run coxph model for large data set with 300 columns( 6 GB )

We are trying to run coxph model using h2o,Rsparkling for large data set with 6 GB with 300 columns, whatever the configuration we take for spark, we are getting memory issues.

As per h2o, we should only have 4 times data size bigger cluster, but we took even 128GB 4 worker nodes with a 128 master node. But still its raising issues.

Please help us to choose the spark configuration needed to run h2o with our current data set