(VLM) A processor and operating system that can use more than 4GB of RAM, which is the limit for systems using 32-bit addresses.
VLM architectures allow application programs and Very Large Databases with more than 4GB of data to be placed entirely in physical memory, with large performance enhancements.
Some recent processors like the DEC Alpha can process 64 bits of data at a time and use addresses wider than 32 bits.
(Unix 98 http://UNIX-systems.org/version2/whatsnew/login_64bit.html).
[How wide are the address busses?]