I'm using ENVI+IDL 4.2 on a Windows XP 64-bit box with 4 GB physical RAM. The ENVI config file seems limited to 2GB of RAM (at least, any more than that entered into the System Preferences dialog goes to a negative value). I've read the Tech Tip on memory ( https://www.rsinc.com/services/techtip.asp?ttid=3346 ) so I understand that the limit would be difficult to push with a 32bit OS (though they imply there is a way to push it to 3GB, but dont provide instructions). Since ENVI is compiled as a 32-bit program, I suppose the limits may be hard to push until RSI compiles a 64bit version of ENVI? Or is there some way to do it with the 32-bit program running on a 64-bit OS? Or could someone point me in the right direction for the implied ability to push the limit to 3 GB? Thanks, -Eric