The maximum amount of virtual memory available depends on the Macintosh model. The Macintosh II, IIx, IIcx, IIci, IIsi, and IIfx models can address a maximum of 13MB of virtual memory. The maximum of 13MB assumes that the user has only a NuBus video card installed. Each additional NuBus card installed in your Macintosh will decrease your maximum amount of virtual memory by 1MB.
The Macintosh SE/30 can address a maximum of 13MB of virtual memory.
Additionally, the Macintosh IIci, IIsi, and IIfx models can operate in 32-bit addressing mode. When operated in 32-bit addressing mode, these Macintosh models can address a maximum of 1GB (one gigabyte, or 1,024MB) of virtual memory.
Note: the maximum amount of virtual memory available on your Macintosh computer is also limited by available space on your hard disk.