Computer science: one reason they went from 32-bit to 64-bit architecture

Self-tutoring about computer science: the tutor mentions one motivation behind the change to 64-bit systems.

The following is according to my understanding.

I recall hearing about 32-bit computers back in the late 80s. I wasn’t sure what it meant at the time, but knew pragmatically it meant “more powerful:” 32-bit computers were new then, up from 16-bit.

Then, starting in the 2000s, one would hear about 64-bit. It became a consideration because some software had two versions: a 32-bit version, then a 64-bit one. Therefore, an everyday user might need to know which their computer was. Some people were very interested, so knew already; others had to find out.

The transition from 32-bit to 64-bit was motivated, partly, by a need to access a bigger memory space. Each unit of storage is identified by its address. in a 32-bit system, one has 2³² unique addresses possible. 2³² is only 4 Gigs.

Four gigabytes might have sounded absurdly large in 2000. Nowadays, however, 8GB of RAM seems nearer the low end, while a 64GB flash drive can be purchased for around 30 dollars CAN. If one wants to use, for example, 8GB, one needs twice the unique addresses that 2³² can supply: namely, 2³³. However, it seems they always double the number of bits in play when they expand, so went to 64-bit systems, to get 2⁶⁴ possible addresses. That represents an address space of 4GBx4GB, or about 16 billion billion in rough figures. That’s one reason why, nowadays, absurd amounts of storage are so common.

Source:

deusinmachina.net: The Evolution of Computing: from 8-bit to 64-bit