ENMTools Relative Rank measure with large datasets

[Shelly]

I am running "Niche Overlap" with ENMTools and have the 'large file overlap/breadth" button set to YES. With this setting the test runs the D and I, but not not the RR (which sounds like a better measure to me). If I set the button to NO, the files are too large for my 8GB of computer RAM to handle.  Does anyone have suggestions for getting the RR to run with the "large file" button on, or how other setting to reduce the memory needed to run RR without the button on.?

Thanks!

Shelly