You'll see this typically listed as a LP64 model. The other common option is ILP64, where int == long == long long == void * == 8.
It should also be noted that this has nothing to do with the underlying hardware. Instead it's a decision made by the OS ABI. There's nothing that says you can't have sizeof(int) == 8 on a 32-bit system.
While it has nothing to do with hardware per se, ILP64 is often seen on platforms, where some significant 32 bit operations (often memory accesses, but surprisingly sometimes even ALU ops) are (or used to be) slower than 64 bit.
It should also be noted that this has nothing to do with the underlying hardware. Instead it's a decision made by the OS ABI. There's nothing that says you can't have sizeof(int) == 8 on a 32-bit system.