What determines the maximum capacity of virtual memory?

#The maximum capacity of the computer's virtual memory is determined by the computer's address structure.

The principle of virtual memory is based on the principle of locality. When the program is loaded, it is not necessary to read all of it into the memory, but only the partial pages or segments that currently need to be executed are read into the memory. This will allow the program to start executing.

During the execution of the program, if the instructions to be executed or the data accessed are not yet in the memory, the processor will notify the operating system to transfer the corresponding page or segment into the memory, and then continue to execute the program.

In addition, the operating system will call out the pages or segments that are temporarily unused in the memory and save them in external memory, thereby freeing up space to store the programs to be loaded and the pages or segments to be loaded. From the user's perspective, the system will have much more memory than it actually has.

Although in terms of actual use, virtual memory allows the process to expand the memory that can be used to the sum of internal and external memory capacity; but the memory addressing of the process is still determined by the address structure of the computer, which determines the virtual memory theoretically the maximum capacity. For example, in a 64-bit system environment, virtual memory technology allows the available memory space of the process to reach 264B, but external memory obviously cannot reach this size, so the maximum capacity of virtual memory is determined by the address structure of the computer.

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