Just for fun and search!
Testing with 1.6.0 and Linux
4 Nodes 1.5 billion documents 7 indexes. 1 query with simple "user id" filter and 20 aggregations using doc values.
Unofficial number by eyeballing iotop about 3G/s reads per node. Takes about 20 seconds to calculate all the 20 aggregations.
The cards are capable of 6G/s but that could just be the nature of the query and why it's not any faster.
Also Linux seems to be performing allot better then Windows and mmapfs and all that swap business.