openning Large .gdb File

I have a very large .gdb file (21 GB) I am having a problem opening. The file has county wide topography with 2-ft contours in a mountainous area (east Tennessee). What is the largest file that GM can open?
Comments
I suggest that you contact Blue Marble Geographics Support directly via e-mail (geohelp@bluemarblegeo.com). Please include a detailed description of your workflow including:
- What version of Global Mapper are you using?
- Is it 32-bit or 64-bit?
- Do you have a licensed version of ArcGIS installed on your computer?
- What is the result when you try to open the .gdb file? Is there an error message?
Cheers,Bob