I am working with a 285,000 row excel spreadsheet and am performing a number of filtering and unique filtering operations. This is a Windows 8.1 64-bit machine, installed with 16 GB of RAM. Office 2013. When doing these operations, Excel only ever uses about 2 gig of the available 16 gig of RAM. How can I get it to use more and work through the operations faster? It is only using a small amount of CPU and virtually no disc I/O.