The native Realsoft 3D file format has been improved to take advantage of 64 bit platforms. A 64 bit version will write 64 bit format and a 32 bit version will write 32 bit format. If a 32 bit file is read into a 64 bit program, then conversion is applied.

It is also possibe to read 64 bit format into a 32 bit version, as long as the file size is below 2GB limit, which is the maximum size for the current 32 bit IFF format implementation.