Yes, if you use dual ranked DIMMs you can fully populate with 16GB DIMMs, so on a single processor 144GB. 
I am in the process of upgrading the RAM in our single-processor R710 and would like to verify the configuration before buying the memory. If I am reading the documentation correctly, I believe the following memory configuration should work giving us a total of 96GB. using dual-rank 16GB DDR3 RDIMMs (Kingston KTD-PE313LV/16G)
R710 Memory Configuration Help