What is the purpose of having a wider data bus than your internal register size ( and address bus) ?

[Musicfacter]

I don't quite understand what could possibly be the purpose of having a data bus that's wider than your internal registers as the internal registers are responsible for how much information that a computer can process at a given moment right? So if I'm working for a CPU that has a 64 bit data bus but only a 32 bit internal register then what is the point because my processor isn't capable of keeping up with the amount of information its receiving. Furthermore, if my address bus is also only 32 bits wide, then I'm not able to take advantage of this can only store a certain amount of data within a given amount of cycles, which is less than the amount of data its receiving. Someone please explain.

 

[kanewolf]

Some instructions (like AVX) work on multiple registers simultaneously. Floating point data is sometimes 64 bit data, so you have to differentiate your integer registers from your floating point registers.