Dave has an IDLSave file which is just a bit less than 2GB, and Autoplot is still running out of memory. I was thinking it mapped data into memory, and the file size should be fine as long as it's not over 2GB.
There was code in there which copied data into the Java heap. I cleaned up the ByteBuffer use, using slice to get read-only views of the data and FileChannel.map. I need to test this on various platforms to see if there was a good reason for copying out the data. (Performance is good over NFS on my home network, interactively slicing a 100MB spectrogram.)
