Topic List

Click a topic to learn more.


Term of the Moment

housekeeping


Look Up Another Term


Definition: memory capacity


The total memory (RAM) that can be added to a computer depends on the size of the address registers built into the CPU. For example, most 32-bit CPUs have a 32-bit address register that can access 4GB (four gigabytes) of memory.

The maximum memory capacity in a 64-bit computer is essentially limitless (see chart below) because a 64-bit address register can access 16 exabytes of memory. See address register, flat address space and memory.
                   Simultaneous
           Maximum    Bytes
     CPU   Memory   Processed

    8-bit   65KB        1

   16-bit    1MB        2

   32-bit    4GB        4

   64-bit   16EB**      8

 ** Limitless for all intents
    and purposes.  No computer
    contains that much RAM.
    See binary values.