VA Smalltalk has support for running as a native 32-bit or 64-bit application. VA Smalltalk v9.0 was the first release to support running as a native 64-bit application on Windows. There is often confusion concerning the advantages of 64-bit. Typically this involves the assumption that migrating a program from 32-bit to 64-bit means the program is going to run faster. While this certainly can be the case, more often the 64-bit program will appear to have similar performance and measurably may, in fact, be a little bit slower. In general, this is due to more bits being shuffled around the various components of a machine's architecture. The more compelling reasons to consider a move to 64-bit have more to do with:

The VA Smalltalk virtual machine, image and programming model abstracts developers away from such low-level concepts as bitness. However, differences can present themselves when the VA Smalltalk system calls out to external code (i.e. C Shared Library), whose interfaces must be described within Smalltalk. These interfaces may vary according to bitness, so VA Smalltalk provides the necessary facilities to help developers deal with this additional detail.